On Saturday, June 22, 2019 at 5:58:02 PM UTC-4, Commander Kinsey wrote:
On Sat, 22 Jun 2019 17:03:08 +0100, TMS320 wrote:

On 21/06/2019 21:19, Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know when to
switch to trickle charge?

It doesn't.

Mine does, if I start my car when the battery is say 80% full, the voltage will be 14.4V. After a while, something causes that voltage to drop to 13.8, because something knows the battery is full and should no longer be charged at a high rate.


Go find a description of the voltage regulator/alternator and/or a
schematic for that car. Give us the references. If something is telling
the VR/alternator what voltage to target, then there must be an additional
wire or connection of some kind. I have not seen that. The other possibilities
are that the VR itself lowers the target voltage, based on? Makes no sense
and I've never seen it mentioned anywhere. I just googled for VR and looked
at half a dozen references, all just say the VR targets a specific voltage
period. The other possibility is that when you read the voltage later,
some other load is present that is lowering the system voltage that you see.






I can understand it noticing a drop in
charging current if the battery is on its own, but what if a random
changing load is connected, as there is in a running car?

Ohm's law.

Explain how an alternator or charger can use ohm's law to distinguish between:
1) A car battery which is full, with a load of 10 amps connected to it, like two headlights.
2) A car battery with no load, which is not full yet and draws 10 amps for the charge.

Rod claims that they have an extra sensing wire at the battery terminal
and use the voltage there versus the voltage at the other end of the
cable, to determine the current. I seriously doubt that, for obvious
reasons involving the very large gauge cable and current of interest.
And he can't produce a damn thing from anywhere that says that's what
they do, except his own worthless statements. If it's done that way
anywhere, it's not done on the cars I've seen here, that have just one
battery cable on the positive terminal. Why doesn't someone show us
an example, a description of one of these alleged fancy voltage regulators
that are computer controlled?

On 6/23/19 8:39 AM, trader_4 wrote:

And so far I haven't seen any evidence presented here that shows modern
ones can tell the difference and care about it either. The ones I've
seen, still have a voltage regulator in the alternator that functions
like it has for most of the last century. Rod claims to know so much,
including that they use the resistance of the battery cable to measure
current, but he can't produce anything other than his own flapping BS
gums and he's likely just doing the usual, making it up on the fly
and lying.

One problem with what he's suggesting is the connection from the
cable to
the battery itself if I understand what he's saying. I've seen so many
bad connections
over the years. Wiggling that connection or putting a sheet metal screw
in it changes
the resistance dramatically.
A few feet of wire in an engine compartment won't have much
resistance to measure.
It would take a very sensitive tester to measure that little bit. 14
awg copper wire has about 2.5 ohms resistance per 1000 feet. #2 awg
wire has about 0.16 ohms per 1000 feet.

On Saturday, June 22, 2019 at 7:30:59 PM UTC-4, Commander Kinsey wrote:
On Sat, 22 Jun 2019 16:16:30 +0100, trader_4 wrote:

On Friday, June 21, 2019 at 7:33:38 PM UTC-4, Commander Kinsey wrote:
On Fri, 21 Jun 2019 23:57:52 +0100, Rod Speed wrote:



"Commander Kinsey" wrote in message
news On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian
wrote:

On 21/06/2019 21:19, Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know when to
switch to trickle charge? I can understand it noticing a drop in
charging current if the battery is on its own, but what if a random
changing load is connected, as there is in a running car?

The voltage perhaps.

Why would the voltage change?

That's the way batterys work, the battery voltage does change as its
charged.

That's determined by the alternator or charger.

Nope.

Yip. I can put any voltage I like across a battery's terminals. The battery then chooses how much current is drawn.

Correct, within reason and the physical limits of the battery. A battery
looks like an ideal voltage source connected in series with a low value
resistor.





Let's say the charger/alternator gives out 14.4V initially, to charge the
battery quickly. It'll just sit at 14.4V forever, providing the charger
can give out enough current to charge the slightly flat battery and power
any connected loads.

Its more complicated than that with the current going to the battery and the
battery is charged.

If the battery had no loads connected, it would take a lot less current
when it became full, but the voltage would stay the same.

No it doesn't even with a very crude battery charger.

For example, I'm currently keeping my car's battery topped up with a bench supply overnight. It's set to 13.8V, with a current limiter only to prevent overloading the supply. The voltage stays at 13.8V all the time, sometimes 100mA is drawn, sometimes up to 4A. The only way I or the supply can tell the battery is full, is by the current dropping to 100mA. But it's actually always full, as when 4A is drawn, that's going to a load.

If the charger monitored the current it was providing, how does it know if
the battery is still charging at 10 amps, or if the battery is full and
there's a 10 amp load?

By checking the current actually being delivered to the battery.

I guess that may be true, if the car's computer has two ammeters and subtracts one from the other. But AFAIK, the alternator regulator only works by it's own current sensor. And that current could be going into the battery, or past it to the loads.

The voltage regulator actually senses VOLTAGE, which is why it;s called
a voltage regulator.

No it doesn't. It keeps the voltage at the correct level for charging, which is 14.4V for fast charge and 13.8V for trickle charge. It senses a drop in current to tell when the battery is full.


No it doesn't what? Of course the voltage regulator SENSES VOLTAGE because
otherwise it obviously can't regulate it. It doesn't target CURRENT.
And this is why you keep asking about how the VR knows how much current
is going to the battery vs how much is going to the car. It doesn't.
It doesn't care. It targets VOLTAGE and that's why it's called a VOLTAGE
REGULATOR, not a current regulator. Good grief, this is explained all over
the internet, not hard to find.

On Saturday, June 22, 2019 at 7:25:04 PM UTC-4, Commander Kinsey wrote:
On Sat, 22 Jun 2019 16:29:26 +0100, trader_4 wrote:

On Saturday, June 22, 2019 at 6:41:22 AM UTC-4, Xeno wrote:
On 22/6/19 7:58 pm, Rod Speed wrote:


"Xeno" wrote in message
...
On 22/6/19 9:57 am, Rod Speed wrote:


"Commander Kinsey" wrote in message
news On Fri, 21 Jun 2019 23:57:52 +0100, Rod Speed
wrote:



"Commander Kinsey" wrote in message
news On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian

wrote:

On 21/06/2019 21:19, Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know
when to
switch to trickle charge? I can understand it noticing a drop in
charging current if the battery is on its own, but what if a random
changing load is connected, as there is in a running car?

The voltage perhaps.

Why would the voltage change?

That's the way batterys work, the battery voltage does change as its
charged.

That's determined by the alternator or charger.

Nope.

Yip.

Nope.

I can put any voltage I like across a battery's terminals.

Nope.

The battery then chooses how much current is drawn.

And that current changes depending on the how charged the battery is.

Let's say the charger/alternator gives out 14.4V initially, to
charge the
battery quickly. It'll just sit at 14.4V forever, providing the
charger
can give out enough current to charge the slightly flat battery
and power
any connected loads.

Its more complicated than that with the current going to the
battery and the
battery is charged.

If the battery had no loads connected, it would take a lot less
current
when it became full, but the voltage would stay the same.

No it doesn't even with a very crude battery charger.

For example, I'm currently keeping my car's battery topped up with a
bench supply overnight. It's set to 13.8V, with a current limiter
only to prevent overloading the supply.

It actually specify the current being supplied.

The voltage stays at 13.8V all the time, sometimes 100mA is drawn,
sometimes up to 4A. The only way I or the supply can tell the
battery is full, is by the current dropping to 100mA. But it's
actually always full, as when 4A is drawn, that's going to a load.

What load ? There no load with a battery being charged with a bench
supply.

Correction

Nope.

the *battery* is the *load*.

Not when the battery is fully charges and is being charged
with a bench supply that is delivering 4A to the battery.

Take the case of an alternator charging a battery at ~4 amps. The
battery is the load and it also provides, as part of that function, the
reference *voltage* that the alternator *must have* in order to control
the output.

+1
You are 100% correct.

You do realize who you are dealing with here, right? Here is some of
the other BS he posted and then just continued to lie about, refuse
to acknowledge it was all wrong:

How can one dope be wrong on so many things?



The 737 MCAS doesn't rely on just one AOA sensor (It does)

The FAA would never approve that design (They did)

[snip]

You've already posted all that ****e. Repeating yourself is a sign of illness.

No, arguing with the Aussie troll who has a track record of BS and lies
is the illness. Maybe you don't care about anyone's credibility and
will debate nuclear physics with the village idiot who lies about most
things. Do so at your own risk.

On Sunday, June 23, 2019 at 4:45:51 AM UTC-4, Xeno wrote:
On 23/6/19 1:37 pm, Rod Speed wrote:


"Xeno" wrote in message
...
On 23/6/19 1:45 am, Rod Speed wrote:


"trader_4" wrote in message
...
On Friday, June 21, 2019 at 6:48:31 PM UTC-4, wrote:
On Fri, 21 Jun 2019 23:15:21 +0100, "Commander Kinsey"
wrote:

On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian
wrote:

On 21/06/2019 21:19, Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know
when to
switch to trickle charge?Â* I can understand it noticing a drop in
charging current if the battery is on its own, but what if a
random
changing load is connected, as there is in a running car?

The voltage perhaps.

Why would the voltage change?Â* That's determined by the alternator
or charger.Â* Let's say the charger/alternator gives out 14.4V
initially, to charge the battery quickly.Â* It'll just sit at 14.4V
forever, providing the charger can give out enough current to
charge the slightly flat battery and power any connected loads.
If the battery had no loads connected, it would take a lot less
current when it became full, but the voltage would stay the same.
If the charger monitored the current it was providing, how does it
know if the battery is still charging at 10 amps, or if the
battery is full and there's a 10 amp load?

Not really true with anything but the most primative regulator like
you might see on an old outboard. Voltage is regulated somewhere
between 13.x and 14.x, not just reflecting what the alternator can do
against the load.
Rod is right, they look at current from the alternator

Every car I've seen, the the alternator, the battery
and the rest of the car are tied to one point

But there is normally more than the one wire
at the the positive terminal of the battery.

Parallel circuits,

Nope, the separate wires go to different bits of the car like
the starter, the alternator and the rest of the electrical system.

The starter wire, that big fat one, is *irrelevant* unless starting. The
power to the vehicles *system*, usually fused, is but an extension of
the B+ wire from the alternator. Once the alternator is running and
producing charge, it takes over all electrical supply to the vehicle's
various circuits. Technically, the battery no longer needs to be there,
since all supply is provided by the alternator, but it does serve as a
suppressor of spikes, prevents overvoltage, etc.

+1

Correct again Sir. That's how the cars I've worked on have been wired.
Basically the alternator output wired together with the battery,
starter, and to the rest of the car. Variety of possibilities as to
how exactly those wires meet, but they are all just tied together.









so what?

So its possible to work out what current the battery is taking.

and there is no monitor for what current
is going to the battery vs to the car load.

Wrong when there is normally more than the one
wire at the the positive terminal of the battery.

And Rod is talking computers,

Because thats what his car has.

so how did cars work prior to the 80s?

The regulator uses the voltage it sees which varys
with the load and the charge of the battery.

They didn't have a computer didn't monitor anything
other than the voltage regulator maintained a constant
voltage of ~14v while the car was running.

Its more complicated than that with the voltage.

No it isn't.

Yes it is. He has said more than once that the
voltage just after starting the engine is different
to what it is when the battery is fully charged.

And that is what you would *expect to see* since you have just made a
150-300 amp draw on the battery.

It was that way from the early days and auto batteries charged fine.

Generators do it differently to alternators and we arent discussing
whether they charged fine or not, we are discussing what the
regulator does when the battery is fully charged so that it doesnt
boil off the water in the battery. Thats particularly important
now that most car batterys arent refillable with water anymore.

There may be some modern cars where they do monitor the current going
to the battery, maybe to save energy and increase fuel consumption,

It actually to avoid ****ing the battery by delivering
the same current to the battery when its fully charged.

but it's not necessary to keeping the battery charged.

That isnt what is being discussed either.

There is nothing they can do about the load so they don't
give a **** about the lights.Â* The regulator just watches
alternator current and cranks up the voltage to keep it up.

That's rather bizarre.Â* The alternator monitors current?Â* So, what's
the correct current that it's targeting?Â* 2 amps, 20 amps?Â* 70 amps?
The current depends on what loads are on and the alternator doesn't
know that.Â* Seems to me it keeps the system VOLTAGE at ~14V

No it doesnt. Doing that would overcharge a fully charged battery.

and that has worked for 100 years.

Wrong again, generators do it differently to alternators.

Yes, no argument there. You mean like this;
http://mgaguru.com/mgtech/books/pdf/..._Box_Tests.pdf


Voltage and current control. They were pretty much on the way out by
the time I finished my apprenticeship.

With alternators, voltage is key.

You need to get with the times. Generators went out with button up boots.

That was commenting on that fool ******_4's stupid claim that nothing
has changed in 100 years with car electrical systems. Of course it has.

Electrical systems - yes, alternators - no. The only part that has
significantly changed has been the regulator and that function, in some
case, is being done by the computer. The alternator regulator has been
through a number of changes since its inception. The first were
*mechanical*, using relays to control output. They then progressed to
transistorised and hybrid. Computer control of voltage regulation is
just the next logical progression.


I said that the alternator/VR have been used for the better part of the
last 100 years. Which is true. Now the Aussie asshole wants to start
a separate stupid argument about that.

On Sun, 23 Jun 2019 23:36:35 +1000, Xeno, another brainless, troll-feeding,
senile Australian idiot, blathered:


Ooops, got that arse about - disconnect the *battery* with the 240V
power still connected.

You've been warned, senile Ozzie tard!

On Sun, 23 Jun 2019 06:39:09 -0700 (PDT), tardo_4, another mentally
challenged, troll-feeding, senile Yankietard, blathered again:


And so far I haven't seen any evidence presented here that shows modern
ones can tell the difference and care about it either.

Neither of those two asshole trolls cares about it either, troll-feeding
senile asshole! All they care about is whether they manage to bait as many
senile assholes as possible with their ENDLESS BLATHER! tsk

On Sun, 23 Jun 2019 06:34:29 -0700 (PDT), tardo_4, another mentally
challenged, troll-feeding, senile Yankietard, blathered again:


Pity about that.

Yeah, about another never-ending idiot thread that you idiots keep alive
....until the time when the troll is fed up with you!

On Sun, 23 Jun 2019 06:55:23 -0700 (PDT), tardo_4, another mentally
challenged, troll-feeding, senile Yankietard, blathered again:


How sad do you have to be to collect so many quotes from somebody?


What other way would you suggest to document that Rod is full of **** most
of the time?

The sociopathic troll baits ...and the senile Yank bites, every time! LMAO

On Sunday, June 23, 2019 at 9:36:43 AM UTC-4, Xeno wrote:

But it can't tell the difference between current going to the lights and
to the battery.

It doesn't need to. All it needs to know is the aggregate current draw,
the total. That will be indicated by the voltage.


--

Xeno



The voltage regulator actually doesn't need to actually know the current period.
It just senses the system voltage and adjusts the current to the alternator
rotor to maintain the target voltage of ~14V.

On Sun, 23 Jun 2019 07:22:13 -0700 (PDT), tardo_4, another mentally
challenged, troll-feeding, senile Yankietard, blathered again:


No it doesn't what? Of course the voltage regulator SENSES VOLTAGE because
otherwise it obviously can't regulate it. It doesn't target CURRENT.
And this is why you keep asking about how the VR knows how much current
is going to the battery vs how much is going to the car. It doesn't.
It doesn't care. It targets VOLTAGE and that's why it's called a VOLTAGE
REGULATOR, not a current regulator. Good grief, this is explained all over
the internet, not hard to find.

Why should he find it when he can have so much fun baiting you seniles on
these groups, time and again! Just look at the latest big "success" of his
latest never-ending idiotic thread! tsk

On Sun, 23 Jun 2019 06:53:00 -0700 (PDT), tardo_4, another mentally
challenged, troll-feeding, senile Yankietard, blathered again:


Go find a description of the voltage

No, he won't, senile idiot! He will go and set out yet another bait for all
you assorted seniles on this group, once he is fed up with you in this
thread! BG

On Sun, 23 Jun 2019 07:22:25 -0700 (PDT), tardo_4, another mentally
challenged, troll-feeding, senile Yankietard, blathered again:

You've already posted all that ****e. Repeating yourself is a sign of illness.

No, arguing with the Aussie troll who has a track record of BS and lies
is the illness.

EXACTLY, oh senile one! And so is arguing with the Scottish troll ...even
more so! tsk

On Sunday, June 23, 2019 at 9:56:21 AM UTC-4, Dean Hoffman wrote:
On 6/23/19 8:39 AM, trader_4 wrote:

And so far I haven't seen any evidence presented here that shows modern
ones can tell the difference and care about it either. The ones I've
seen, still have a voltage regulator in the alternator that functions
like it has for most of the last century. Rod claims to know so much,
including that they use the resistance of the battery cable to measure
current, but he can't produce anything other than his own flapping BS
gums and he's likely just doing the usual, making it up on the fly
and lying.

One problem with what he's suggesting is the connection from the
cable to
the battery itself if I understand what he's saying. I've seen so many
bad connections
over the years. Wiggling that connection or putting a sheet metal screw
in it changes
the resistance dramatically.
A few feet of wire in an engine compartment won't have much
resistance to measure.
It would take a very sensitive tester to measure that little bit. 14
awg copper wire has about 2.5 ohms resistance per 1000 feet. #2 awg
wire has about 0.16 ohms per 1000 feet.

Bingo! We have a winner! Exactly what I was thinking when I said
it seems unlikely that they would use the resistance of a heavy, 2g
battery cable to try to measure current flow to the battery.
Especially when cars have worked fine for decades without measuring it
at all. All the systems I've been familiar with the alternator/VR
just target a fixed voltage. You have 3 feet of wire, to determine
whether the battery is getting 100ma or 10 amps, good luck with
that, especially in a potentially noisy environment, with system loads
turning on and off rapidly, etc. Figure out how small those voltages
would be.

Rod just makes crap up on the fly, he's caught doing it all the time
and has zero credibility. If this method exists, I'm still waiting
for a reference that shows it. I just googled for alternators,
VR, charging, and all show the basic system targeting VOLTAGE,
nothing about sensing current flow into or out of the battery.
I think the bottom line is that auto batteries are fine being
presented with ~14V. They either charge if needed or accept a small
current anyway, with no harmful effects. And if not, then how
did alternators/VRs work just fine without computers or fancy
circuitry, for better part of a century?

And note I'm not saying that some cars, somewhere don't have some more
advanced system, it's certainly possible, maybe to slightly reduce
wasted energy, at the expense of increased complexity. But the OP
was asking about charging systems and batteries in general and if
something fancy is going on, it's not central to the question he asked.
And if this system does exist, still waiting for Rod to show it to us.....

On 24/6/19 12:45 am, trader_4 wrote:
On Sunday, June 23, 2019 at 9:36:43 AM UTC-4, Xeno wrote:

But it can't tell the difference between current going to the lights and
to the battery.

It doesn't need to. All it needs to know is the aggregate current draw,
the total. That will be indicated by the voltage.


--

Xeno



The voltage regulator actually doesn't need to actually know the current period.
It just senses the system voltage and adjusts the current to the alternator
rotor to maintain the target voltage of ~14V.

+1

That's what I said - the aggregate current draw will be indicated by the
voltage.

;-)


--

Xeno


Nothing astonishes Noddy so much as common sense and plain dealing.
(with apologies to Ralph Waldo Emerson)

On 22/06/2019 22:58, Commander Kinsey wrote:
On Sat, 22 Jun 2019 17:03:08 +0100, TMS320 wrote:
On 21/06/2019 21:19, Commander Kinsey wrote:

How does a lead acid battery charger (or car alternator) know when to
switch to trickle charge?

It doesn't.

Mine does, if I start my car when the battery is say 80% full, the
voltage will be 14.4V.* After a while, something causes that voltage to
drop to 13.8, because something knows the battery is full and should no
longer be charged at a high rate.

I can understand it noticing a drop in
charging current if the battery is on its own, but what if a random
changing load is connected, as there is in a running car?

Ohm's law.

Explain how an alternator or charger can use ohm's law to distinguish
between:

To determine current, measure the voltage across a series resistor, duh.

1) A car battery which is full, with a load of 10 amps connected to it,
like two headlights.
2) A car battery with no load, which is not full yet and draws 10 amps
for the charge.

Two resistors?

On Sunday, June 23, 2019 at 12:27:13 PM UTC-4, TMS320 wrote:
On 22/06/2019 22:58, Commander Kinsey wrote:
On Sat, 22 Jun 2019 17:03:08 +0100, TMS320 wrote:
On 21/06/2019 21:19, Commander Kinsey wrote:

How does a lead acid battery charger (or car alternator) know when to
switch to trickle charge?

It doesn't.

Mine does, if I start my car when the battery is say 80% full, the
voltage will be 14.4V.Â* After a while, something causes that voltage to
drop to 13.8, because something knows the battery is full and should no
longer be charged at a high rate.

I can understand it noticing a drop in
charging current if the battery is on its own, but what if a random
changing load is connected, as there is in a running car?

Ohm's law.

Explain how an alternator or charger can use ohm's law to distinguish
between:

To determine current, measure the voltage across a series resistor, duh.

1) A car battery which is full, with a load of 10 amps connected to it,
like two headlights.
2) A car battery with no load, which is not full yet and draws 10 amps
for the charge.

Two resistors?

The issue is not how it can be measured, the question is if any cars
actually do it, ie measure the current flowing into the battery and
use it to control the alternator. I've never seen it, never heard of
it. So far, all we have is Rod's flapping gums and he's made all kinds
of false claims and lies here. And he said they don't use a resistor,
that they just use the resistance of the battery cable. That doesn't
make sense to us, for obvious reasons. So, we're still waiting for
Rod to show us some documentation of what he claims cars do......

On Sun, 23 Jun 2019 17:27:09 +0100, TMS320, yet another brain damaged,
troll-feeding, senile asshole, blathered again:



Two resistors?

Two idiots (a troll and a troll-feeding senile asshole) having a
"conversation"? BG

"trader_4" wrote in message
...
On Saturday, June 22, 2019 at 3:55:09 PM UTC-4, Commander Kinsey wrote:
On Sat, 22 Jun 2019 20:44:15 +0100, trader_4
wrote:

On Saturday, June 22, 2019 at 3:06:28 PM UTC-4, Rod Speed wrote:
"Commander Kinsey" wrote in message
news On Sat, 22 Jun 2019 15:28:21 +0100, trader_4
wrote:

On Friday, June 21, 2019 at 6:48:31 PM UTC-4,
wrote:
On Fri, 21 Jun 2019 23:15:21 +0100, "Commander Kinsey"
wrote:

On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian

wrote:

On 21/06/2019 21:19, Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know
when
to
switch to trickle charge? I can understand it noticing a drop
in
charging current if the battery is on its own, but what if a
random
changing load is connected, as there is in a running car?

The voltage perhaps.

Why would the voltage change? That's determined by the
alternator or
charger. Let's say the charger/alternator gives out 14.4V
initially,
to charge the battery quickly. It'll just sit at 14.4V forever,
providing the charger can give out enough current to charge the
slightly flat battery and power any connected loads. If the
battery
had no loads connected, it would take a lot less current when it
became
full, but the voltage would stay the same. If the charger
monitored
the current it was providing, how does it know if the battery is
still
charging at 10 amps, or if the battery is full and there's a 10
amp
load?

Not really true with anything but the most primative regulator
like
you might see on an old outboard. Voltage is regulated somewhere
between 13.x and 14.x, not just reflecting what the alternator can
do
against the load.
Rod is right, they look at current from the alternator

Every car I've seen, the the alternator, the battery and the
rest of the car are tied to one point and there is no monitor
for what current is going to the battery vs to the car load.
And Rod is talking computers,
so how did cars work prior to the 80s? They didn't have a computer
didn't monitor anything other than the voltage regulator maintained
a constant voltage of ~14v while the car was running. It was that
way from the early days and auto batteries charged fine.

There may be some modern cars where they do monitor the current
going
to the battery, maybe to save energy and increase fuel consumption,
but it's not necessary to keeping the battery charged.

I doubt it saves much energy. Charging a lead acid at 13.8 to 14.4V
continuously, wastes **** all power. More likely it can charge at a
higher voltage to begin with to make the battery full quickly, then
pull
back to trickle when needed. Handy if you make a habit of using a
lot of
accessories like lights when the engine is off then need it charged
quickly when you drive for 10 minutes. Or if like me you drive for
100
yards at a time and are using the starter a lot (or have one of
those stop
start engines). Older cars would run out of battery if you did lots
of
short journeys, as there was no fast charge.

There is nothing they can do about the load so they don't give a
****
about the
lights. The regulator just watches alternator current and cranks
up
the voltage to keep it up.

That's rather bizarre. The alternator monitors current? So,
what's
the correct current that it's targeting? 2 amps, 20 amps? 70
amps?
The current depends on what loads are on and the alternator doesn't
know that. Seems to me it keeps the system VOLTAGE at ~14V and
that
has worked for 100 years.

It would have to monitor the current going into the battery, by
having at
least two ammeters,

Just two cables from the battery positive terminal, one to the
alternator
and one
to the rest of the electrical system and measure the voltage drop over
those.

or have all the positive wires join somewhere

They do, the positive terminal of the battery.

and measure the branch off to the battery.

Just subtract the current to the rest of the electrical system
from the current going from the alternator to the battery
terminal. That gives you the current going into the battery.

When you have an actual credible cite that describes this alleged
system, post it. Until then, all you are doing is making crap up on the
fly.

I can believe him, I've observed my car's alternator change from 14.4V to
13.8V after it's been running for a bit, so it must know the battery is
full.

Like claiming that all cars have more than one wire to the battery
positive terminal.

I've never seen one that doesn't. Usually I see one for the alternator,
one for the starter, and one for everything else. Why would you have
only one? These are high currents, best to connect things directly.

Well, wherever you are, cars must be put together differently. I've
worked
on American cars, BMW, Mercedes, none had anything more than one cable
to the positive battery terminal. Additionally, there are aftermarket
battery cables for generic replacement, I've never seen one of those with
more than one cable either. Just because you only have one cable, doesn't
mean that the starter, etc can't be connected, it's just wire. There are
many ways it can be connected and routed, there is no reason more than one
cable needs to go to the battery.

Must be why so many cars have more than one.

Or that cars use the resistance of the large gage cable to measure
current. You just pulled that one from your ass, it's rather unlikely
for some obvious reasons. But hey, you claim that's how it's done,
provide some references.......

I do hate it when people say "for obvious reasons" - they are never
obvious to anyone else.


Pity about that.



That is precisely how you measure current, by a voltage drop across a
known resistance. And they certainly don't want to add more resistance
to something trying to carry 100s of amps. I guess they could also use
an amp clamp, but that would cost more.

"Dean Hoffman" wrote in message
...
On 6/23/19 8:39 AM, trader_4 wrote:

And so far I haven't seen any evidence presented here that shows modern
ones can tell the difference and care about it either. The ones I've
seen, still have a voltage regulator in the alternator that functions
like it has for most of the last century. Rod claims to know so much,
including that they use the resistance of the battery cable to measure
current, but he can't produce anything other than his own flapping BS
gums and he's likely just doing the usual, making it up on the fly
and lying.

One problem with what he's suggesting is the connection from the cable to
the battery itself

Nope.

if I understand what he's saying.

You clearly dont.

I've seen so many bad connections over the years. Wiggling that
connection or putting a sheet metal screw in it changes the resistance
dramatically.

Yes, but that has no effect on the RESISTANCE
of the substantial wire between the positive
terminal connector and the other end of that wire.

A few feet of wire in an engine compartment won't have much resistance to
measure.

What is measured is the voltage drop across that wire.
Thats acting like an ammeter shunt.

It would take a very sensitive tester to measure that little bit.

Trivial to measure the VOLTAGE DROP across that wire.

14 awg copper wire has about 2.5 ohms resistance per 1000 feet. #2 awg
wire has about 0.16 ohms per 1000 feet.

"trader_4" wrote in message
...
On Sunday, June 23, 2019 at 4:45:51 AM UTC-4, Xeno wrote:
On 23/6/19 1:37 pm, Rod Speed wrote:


"Xeno" wrote in message
...
On 23/6/19 1:45 am, Rod Speed wrote:


"trader_4" wrote in message
...
On Friday, June 21, 2019 at 6:48:31 PM UTC-4, wrote:
On Fri, 21 Jun 2019 23:15:21 +0100, "Commander Kinsey"
wrote:

On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian
wrote:

On 21/06/2019 21:19, Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know
when to
switch to trickle charge? I can understand it noticing a drop
in
charging current if the battery is on its own, but what if a
random
changing load is connected, as there is in a running car?

The voltage perhaps.

Why would the voltage change? That's determined by the alternator
or charger. Let's say the charger/alternator gives out 14.4V
initially, to charge the battery quickly. It'll just sit at 14.4V
forever, providing the charger can give out enough current to
charge the slightly flat battery and power any connected loads.
If the battery had no loads connected, it would take a lot less
current when it became full, but the voltage would stay the same.
If the charger monitored the current it was providing, how does it
know if the battery is still charging at 10 amps, or if the
battery is full and there's a 10 amp load?

Not really true with anything but the most primative regulator like
you might see on an old outboard. Voltage is regulated somewhere
between 13.x and 14.x, not just reflecting what the alternator can
do
against the load.
Rod is right, they look at current from the alternator

Every car I've seen, the the alternator, the battery
and the rest of the car are tied to one point

But there is normally more than the one wire
at the the positive terminal of the battery.

Parallel circuits,

Nope, the separate wires go to different bits of the car like
the starter, the alternator and the rest of the electrical system.

The starter wire, that big fat one, is *irrelevant* unless starting. The
power to the vehicles *system*, usually fused, is but an extension of
the B+ wire from the alternator. Once the alternator is running and
producing charge, it takes over all electrical supply to the vehicle's
various circuits. Technically, the battery no longer needs to be there,
since all supply is provided by the alternator, but it does serve as a
suppressor of spikes, prevents overvoltage, etc.

+1

Correct again Sir. That's how the cars I've worked on have been wired.
Basically the alternator output wired together with the battery,
starter, and to the rest of the car. Variety of possibilities as to
how exactly those wires meet, but they are all just tied together.









so what?

So its possible to work out what current the battery is taking.

and there is no monitor for what current
is going to the battery vs to the car load.

Wrong when there is normally more than the one
wire at the the positive terminal of the battery.

And Rod is talking computers,

Because thats what his car has.

so how did cars work prior to the 80s?

The regulator uses the voltage it sees which varys
with the load and the charge of the battery.

They didn't have a computer didn't monitor anything
other than the voltage regulator maintained a constant
voltage of ~14v while the car was running.

Its more complicated than that with the voltage.

No it isn't.

Yes it is. He has said more than once that the
voltage just after starting the engine is different
to what it is when the battery is fully charged.

And that is what you would *expect to see* since you have just made a
150-300 amp draw on the battery.

It was that way from the early days and auto batteries charged fine.

Generators do it differently to alternators and we arent discussing
whether they charged fine or not, we are discussing what the
regulator does when the battery is fully charged so that it doesnt
boil off the water in the battery. Thats particularly important
now that most car batterys arent refillable with water anymore.

There may be some modern cars where they do monitor the current
going
to the battery, maybe to save energy and increase fuel consumption,

It actually to avoid ****ing the battery by delivering
the same current to the battery when its fully charged.

but it's not necessary to keeping the battery charged.

That isnt what is being discussed either.

There is nothing they can do about the load so they don't
give a **** about the lights. The regulator just watches
alternator current and cranks up the voltage to keep it up.

That's rather bizarre. The alternator monitors current? So, what's
the correct current that it's targeting? 2 amps, 20 amps? 70 amps?
The current depends on what loads are on and the alternator doesn't
know that. Seems to me it keeps the system VOLTAGE at ~14V

No it doesnt. Doing that would overcharge a fully charged battery.

and that has worked for 100 years.

Wrong again, generators do it differently to alternators.

Yes, no argument there. You mean like this;
http://mgaguru.com/mgtech/books/pdf/..._Box_Tests.pdf


Voltage and current control. They were pretty much on the way out by
the time I finished my apprenticeship.

With alternators, voltage is key.

You need to get with the times. Generators went out with button up
boots.

That was commenting on that fool ******_4's stupid claim that nothing
has changed in 100 years with car electrical systems. Of course it has.

Electrical systems - yes, alternators - no. The only part that has
significantly changed has been the regulator and that function, in some
case, is being done by the computer. The alternator regulator has been
through a number of changes since its inception. The first were
*mechanical*, using relays to control output. They then progressed to
transistorised and hybrid. Computer control of voltage regulation is
just the next logical progression.

I said that the alternator/VR have been used for the
better part of the last 100 years. Which is true.

In fact **** all cars and trucks had an alternator before
the 60s so you are just plain wrong, as always.

"trader_4" wrote in message
...
On Sunday, June 23, 2019 at 9:36:43 AM UTC-4, Xeno wrote:

But it can't tell the difference between current going to the lights
and
to the battery.

It doesn't need to. All it needs to know is the aggregate current draw,
the total. That will be indicated by the voltage.

The voltage regulator actually doesn't need to actually know the current
period.
It just senses the system voltage and adjusts the current to the
alternator
rotor to maintain the target voltage of ~14V.

The PHuckers voltage clearly isnt maintained at just one voltage.

On Mon, 24 Jun 2019 04:35:45 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:


One problem with what he's suggesting is the connection from the cable to
the battery itself

Nope.

Nope? You disagree? Well, that's news! LOL

--
Kerr-Mudd,John addressing senile Rot:
"Auto-contradictor Rod is back! (in the KF)"
MID:

"trader_4" wrote in message
...
On Sunday, June 23, 2019 at 9:56:21 AM UTC-4, Dean Hoffman wrote:
On 6/23/19 8:39 AM, trader_4 wrote:

And so far I haven't seen any evidence presented here that shows modern
ones can tell the difference and care about it either. The ones I've
seen, still have a voltage regulator in the alternator that functions
like it has for most of the last century. Rod claims to know so much,
including that they use the resistance of the battery cable to measure
current, but he can't produce anything other than his own flapping BS
gums and he's likely just doing the usual, making it up on the fly
and lying.

One problem with what he's suggesting is the connection from the
cable to
the battery itself if I understand what he's saying. I've seen so many
bad connections
over the years. Wiggling that connection or putting a sheet metal screw
in it changes
the resistance dramatically.
A few feet of wire in an engine compartment won't have much
resistance to measure.
It would take a very sensitive tester to measure that little bit. 14
awg copper wire has about 2.5 ohms resistance per 1000 feet. #2 awg
wire has about 0.16 ohms per 1000 feet.

Bingo! We have a winner!

Nope.

Exactly what I was thinking when I said it seems unlikely
that they would use the resistance of a heavy, 2g battery
cable to try to measure current flow to the battery.

What is measured is the voltage drop across that cable.
Thats what gives you the current thru it, stupid.

You have 3 feet of wire, to determine whether the battery
is getting 100ma or 10 amps, good luck with that,

Trivially easy to do by measuring the voltage drop across that cable.

especially in a potentially noisy environment, with
system loads turning on and off rapidly, etc.

That doesnt happen with the car running.

Figure out how small those voltages would be.

Trivially easy to measure and the arent that small
with the total current the entire electrical system
takes and with the current thats charging the battery.

And note I'm not saying that some cars, somewhere don't have
some more advanced system, it's certainly possible, maybe to slightly
reduce wasted energy, at the expense of increased complexity.

Nothing to do with wasted energy.

On Mon, 24 Jun 2019 04:25:49 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

more than one cable either. Just because you only have one cable, doesn't
mean that the starter, etc can't be connected, it's just wire. There are
many ways it can be connected and routed, there is no reason more than one
cable needs to go to the battery.

Must be why so many cars have more than one.

So, how MANY cars did you check for their wires, senile Mr Know-it-all?

--
"Anonymous" to trolling senile Rot Speed:
"You can **** off as you know less than pig **** you sad
little ignorant ****."
MID:

On Sun, 23 Jun 2019 14:39:09 +0100, trader_4 wrote:

On Saturday, June 22, 2019 at 5:22:54 PM UTC-4, Commander Kinsey wrote:
On Sat, 22 Jun 2019 16:45:08 +0100, Rod Speed wrote:



"trader_4" wrote in message
...
On Friday, June 21, 2019 at 6:48:31 PM UTC-4, wrote:
On Fri, 21 Jun 2019 23:15:21 +0100, "Commander Kinsey"
wrote:

On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian
wrote:

On 21/06/2019 21:19, Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know when to
switch to trickle charge? I can understand it noticing a drop in
charging current if the battery is on its own, but what if a random
changing load is connected, as there is in a running car?

The voltage perhaps.

Why would the voltage change? That's determined by the alternator or
charger. Let's say the charger/alternator gives out 14.4V initially, to
charge the battery quickly. It'll just sit at 14.4V forever, providing
the charger can give out enough current to charge the slightly flat
battery and power any connected loads. If the battery had no loads
connected, it would take a lot less current when it became full, but the
voltage would stay the same. If the charger monitored the current it
was providing, how does it know if the battery is still charging at 10
amps, or if the battery is full and there's a 10 amp load?

Not really true with anything but the most primative regulator like
you might see on an old outboard. Voltage is regulated somewhere
between 13.x and 14.x, not just reflecting what the alternator can do
against the load.
Rod is right, they look at current from the alternator

Every car I've seen, the the alternator, the battery
and the rest of the car are tied to one point

But there is normally more than the one wire
at the the positive terminal of the battery.

and there is no monitor for what current
is going to the battery vs to the car load.

Wrong when there is normally more than the one
wire at the the positive terminal of the battery.

And Rod is talking computers,

Because thats what his car has.

so how did cars work prior to the 80s?

The regulator uses the voltage it sees which varys
with the load and the charge of the battery.

That was my original question - on an old car, there is no way for the regulator to tell the difference between the battery still charging at 10 amps and the headlamps being switched on.


And so far I haven't seen any evidence presented here that shows modern
ones can tell the difference and care about it either. The ones I've
seen, still have a voltage regulator in the alternator that functions
like it has for most of the last century. Rod claims to know so much,
including that they use the resistance of the battery cable to measure
current, but he can't produce anything other than his own flapping BS
gums and he's likely just doing the usual, making it up on the fly
and lying.

What he says sounds very easy to implement, and it would make sense to allow the battery to be put on fast charge after starting it, then go back to trickle later. And my own car certainly does change the voltage after a while. 14.4 then 13.8.

On Sun, 23 Jun 2019 14:36:35 +0100, Xeno wrote:

On 23/6/19 9:24 am, Commander Kinsey wrote:
On Sat, 22 Jun 2019 11:41:15 +0100, Xeno wrote:


the *battery* is the *load*.

Not when the battery is fully charges and is being charged
with a bench supply that is delivering 4A to the battery.

Take the case of an alternator charging a battery at ~4 amps. The
battery is the load and it also provides, as part of that function, the
reference *voltage* that the alternator *must have* in order to control
the output.

I believe the reason Rod mentioned load as being seperate to the battery
is this thread is about my car, with a fault that draws current from the
battery, and it's also connected to a bench supply. In this situation,
we refer to "load" as the faulty alarm system. I originally asked how
an alternator could distinguish between the battery charging, and a load
such as your headlamps being on.

In the process of being charged it is using electric current. That
makes it the load.

See above.

What happens to the charger when you disconnect the power with the
battery connected? It should, if designed correctly, shut down since it
no longer sees a load. Otherwise it may destroy itself.

Ooops, got that arse about - disconnect the *battery* with the 240V
power still connected.

How would it destroy itself? Mine in fact just stay at 13.8V open circuit.

Bull****. You're telling me that a bench supply with a battery on the
output and no 240V input will blow up if it doesn't shut down? Wrong.

The battery is the load. And I'm referring to a charger and the leads to
the battery being disconnected, not the 240V input. The same as if you
open circuit the battery on a running, and charging, alternator. It can
be done but there is a high risk of a spike zapping something. The
battery acts to dampen spikes and it's removal from the circuit exposes
the regulator and any other electronic components to spikes.

Yes, but that has nothing to do with having a charger with no battery on it.

Absolutely wrong. The output end of the supply (which probably ends
with smoothing capacitors) is just kept at the normal output voltage by
the battery.

I used the term *charger* for a very good reason.

They are one and the same, constant voltage current limited supplies

Even when it is fully charged it will still take a trickle charge

4A isnt a trickle charge.

That depends entirely on the amp hour rating of the battery.
Also, my bench charger will start off at 4 amps, its maximum capacity.
As the battery becomes charged, that current will drop down to *1 amp*
and, from that point, it will maintain a *trickle charge*.

How ****ing big is that battery?! When I charge a 60Ah lead acid at
13.8V, it drops to about 150mA when full.

When I was working on trucks, it wasn't unusual to see 4 x 12 Volt, 200
AH batteries wired series-parallel, so yes, 1 amp can be a trickle.

Yes with 400Ah I can believe a 1A trickle.

From Wikipedia;
For lead-acid batteries under no load float charging (such as
in SLI batteries), trickle charging happens naturally at the
end-of-charge, when the lead-acid battery internal resistance
to the charging current increases enough to reduce additional
charging current to a trickle, hence the name. In such cases,
the trickle charging equals the energy expended by the
lead-acid battery splitting the water in the electrolyte into
hydrogen and oxygen gases

Trouble is you might want to do a bulk charge first, at 14.4V.

The car alternator regulator is no different. It sees the battery as a
load, determines the voltage reference and pumps up its output.

All it can do is supply a certain voltage. 13.8V is safe. If it uses
14.4V or higher, it has to know when to back off to 13.8. It cannot do
that if there is an external current draw like headlamp, as it won't
know if they're switched on, or if the battery is drawing that current.

The regulator has a Zener diode to *limit* the voltage. An external
current draw will lower the voltage.

Only if the alternator can't provide enough current.

When the
regulator sees the battery voltage at the peak setpoint,

You can't tell a battery is full by voltage. You can only tell by it
drawing less current. The voltage is determined by the charger.

The voltage at the battery will be determined by the battery's *internal
resistance*. As that battery's internal resistance goes higher, as it
will do as it becomes charged, the voltage will go higher and current
will reduce.

********. If I connect a 13.8V regulated supply (or charger, same thing) to a car battery sat on my bench, provided it's not needing a lot of current to charge it from empty, the charger will keep the terminals at precisely 13.8V. The only thing that changes as it becomes completely full is the current, so that's what the charger has to monitor.

it too will
drop the current to a trickle.

Actually it drops the voltage, to 13.8. I used to have a solar battery
regulator which had very detailed instructions saying how it worked. It
took the voltage of the solar cells and altered it up or down a bit to
suit the battery condition.

If you add a load, say by turning
headlights on, that is in *parallel* to the battery and it will drop the
system voltage down a tad. The regulator will see that and pump up the
output current appropriately. The current will apportion itself to the
*two* loads as appropriate to their individual internal resistances.

But it can't tell the difference between current going to the lights and
to the battery.

It doesn't need to. All it needs to know is the aggregate current draw,
the total. That will be indicated by the voltage.

If it's going to switch between fast and slow charge rates, it needs to know where that current is going. There is no way in hell it can tell from it's own internal sensing whether your battery is charging at 10 amps, or you have two 60W headlights switched on.

On Sun, 23 Jun 2019 11:32:57 +0100, Mr Pounder Esquire wrote:

Commander Kinsey wrote:
On Sat, 22 Jun 2019 11:55:51 +0100, Mr Pounder Esquire
wrote:
Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know when
to switch to trickle charge? I can understand it noticing a drop in
charging current if the battery is on its own, but what if a random
changing load is connected, as there is in a running car?

Asks the unemployable ******/troll with a 20 year old worthless
degree and a stated IQ of 138. Odd that a few years ago your stated
IQ was 142.

It has always been 135. And the degree is 22 years old.

My mistake.

"I have an IQ of 140".
"I am seldom wrong".
(Peter Hucker)

It may be possible it varies slightly, I've taken it in several places.

"I have driven a Ford Sierra 1.6 at 90mph on single track roads
with passing places in the NW of Scotland. ****ing great fun"!

Not my fault you're too thick to drive fast.

"Vauxhalls and Fords are mass produced. VWs are engineered".

What do you find wrong with that?

[snip more silly quotes, collected by Pounder the OCD stalker]

On Mon, 24 Jun 2019 04:47:30 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

FLUSH senile asshole's latest troll****

--
about senile Rot Speed:
"This is like having a conversation with someone with brain damage."
MID:

On Mon, 24 Jun 2019 04:40:25 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:


In fact **** all cars and trucks had an alternator before
the 60s so you are just plain wrong, as always.

Shove your alternator up yours, senile ashole! That might shut you up for a
while!

--
addressing nym-shifting senile Rodent:
"You on the other hand are a heavyweight bull****ter who demonstrates
your particular prowess at it every day."
MID:

On Mon, 24 Jun 2019 04:41:35 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:


The PHuckers voltage

You can shove PHucker up yours, too, senile asshole! LOL

--
Richard addressing Rot Speed:
"**** you're thick/pathetic excuse for a troll."
MID:

Commander Kinsey wrote:
On Sun, 23 Jun 2019 11:32:57 +0100, Mr Pounder Esquire
wrote:
Commander Kinsey wrote:
On Sat, 22 Jun 2019 11:55:51 +0100, Mr Pounder Esquire
wrote:
Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know when
to switch to trickle charge? I can understand it noticing a drop
in charging current if the battery is on its own, but what if a
random changing load is connected, as there is in a running car?

Asks the unemployable ******/troll with a 20 year old worthless
degree and a stated IQ of 138. Odd that a few years ago your stated
IQ was 142.

It has always been 135. And the degree is 22 years old.

My mistake.

"I have an IQ of 140".
"I am seldom wrong".
(Peter Hucker)

It may be possible it varies slightly, I've taken it in several
places.

Yeah, right.

"I have driven a Ford Sierra 1.6 at 90mph on single track roads
with passing places in the NW of Scotland. ****ing great fun"!

Not my fault you're too thick to drive fast.

"Vauxhalls and Fords are mass produced. VWs are engineered".

What do you find wrong with that?

[snip more silly quotes, collected by Pounder the OCD stalker]

They are your quotes.

On Sun, 23 Jun 2019 21:30:16 +0100, Mr Pounder Esquire wrote:

Commander Kinsey wrote:
On Sun, 23 Jun 2019 11:32:57 +0100, Mr Pounder Esquire
wrote:
Commander Kinsey wrote:
On Sat, 22 Jun 2019 11:55:51 +0100, Mr Pounder Esquire
wrote:
Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know when
to switch to trickle charge? I can understand it noticing a drop
in charging current if the battery is on its own, but what if a
random changing load is connected, as there is in a running car?

Asks the unemployable ******/troll with a 20 year old worthless
degree and a stated IQ of 138. Odd that a few years ago your stated
IQ was 142.

It has always been 135. And the degree is 22 years old.

My mistake.

"I have an IQ of 140".
"I am seldom wrong".
(Peter Hucker)

It may be possible it varies slightly, I've taken it in several
places.

Yeah, right.

Yip. So what's yours? Bod admitted to 98.

"I have driven a Ford Sierra 1.6 at 90mph on single track roads
with passing places in the NW of Scotland. ****ing great fun"!

Not my fault you're too thick to drive fast.

"Vauxhalls and Fords are mass produced. VWs are engineered".

What do you find wrong with that?

[snip more silly quotes, collected by Pounder the OCD stalker]

They are your quotes.

You collected them, which makes you a psychopath.

On Sun, 23 Jun 2019 14:34:29 +0100, trader_4 wrote:

On Saturday, June 22, 2019 at 3:55:09 PM UTC-4, Commander Kinsey wrote:
On Sat, 22 Jun 2019 20:44:15 +0100, trader_4 wrote:

On Saturday, June 22, 2019 at 3:06:28 PM UTC-4, Rod Speed wrote:
"Commander Kinsey" wrote in message
news On Sat, 22 Jun 2019 15:28:21 +0100, trader_4
wrote:

On Friday, June 21, 2019 at 6:48:31 PM UTC-4, wrote:
On Fri, 21 Jun 2019 23:15:21 +0100, "Commander Kinsey"
wrote:

On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian
wrote:

On 21/06/2019 21:19, Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know when
to
switch to trickle charge? I can understand it noticing a drop in
charging current if the battery is on its own, but what if a random
changing load is connected, as there is in a running car?

The voltage perhaps.

Why would the voltage change? That's determined by the alternator or
charger. Let's say the charger/alternator gives out 14.4V initially,
to charge the battery quickly. It'll just sit at 14.4V forever,
providing the charger can give out enough current to charge the
slightly flat battery and power any connected loads. If the battery
had no loads connected, it would take a lot less current when it became
full, but the voltage would stay the same. If the charger monitored
the current it was providing, how does it know if the battery is still
charging at 10 amps, or if the battery is full and there's a 10 amp
load?

Not really true with anything but the most primative regulator like
you might see on an old outboard. Voltage is regulated somewhere
between 13.x and 14.x, not just reflecting what the alternator can do
against the load.
Rod is right, they look at current from the alternator

Every car I've seen, the the alternator, the battery and the
rest of the car are tied to one point and there is no monitor
for what current is going to the battery vs to the car load.
And Rod is talking computers,
so how did cars work prior to the 80s? They didn't have a computer
didn't monitor anything other than the voltage regulator maintained
a constant voltage of ~14v while the car was running. It was that
way from the early days and auto batteries charged fine.

There may be some modern cars where they do monitor the current going
to the battery, maybe to save energy and increase fuel consumption,
but it's not necessary to keeping the battery charged.

I doubt it saves much energy. Charging a lead acid at 13.8 to 14.4V
continuously, wastes **** all power. More likely it can charge at a
higher voltage to begin with to make the battery full quickly, then pull
back to trickle when needed. Handy if you make a habit of using a lot of
accessories like lights when the engine is off then need it charged
quickly when you drive for 10 minutes. Or if like me you drive for 100
yards at a time and are using the starter a lot (or have one of those stop
start engines). Older cars would run out of battery if you did lots of
short journeys, as there was no fast charge.

There is nothing they can do about the load so they don't give a ****
about the
lights. The regulator just watches alternator current and cranks up
the voltage to keep it up.

That's rather bizarre. The alternator monitors current? So, what's
the correct current that it's targeting? 2 amps, 20 amps? 70 amps?
The current depends on what loads are on and the alternator doesn't
know that. Seems to me it keeps the system VOLTAGE at ~14V and that
has worked for 100 years.

It would have to monitor the current going into the battery, by having at
least two ammeters,

Just two cables from the battery positive terminal, one to the alternator
and one
to the rest of the electrical system and measure the voltage drop over
those.

or have all the positive wires join somewhere

They do, the positive terminal of the battery.

and measure the branch off to the battery.

Just subtract the current to the rest of the electrical system
from the current going from the alternator to the battery
terminal. That gives you the current going into the battery.

When you have an actual credible cite that describes this alleged system, post it. Until then, all you are doing is making crap up on the fly.

I can believe him, I've observed my car's alternator change from 14.4V to 13.8V after it's been running for a bit, so it must know the battery is full.

Like claiming that all cars have more than one wire to the battery positive terminal.

I've never seen one that doesn't. Usually I see one for the alternator, one for the starter, and one for everything else. Why would you have only one? These are high currents, best to connect things directly.

Well, wherever you are, cars must be put together differently.

Scotland.

I've worked
on American cars, BMW, Mercedes, none had anything more than one cable
to the positive battery terminal.

I've seen Ford, Fiat, VW, Renault, Rover, Range Rover. Always 2 or 3 cables. Far easier to attach them all to the battery. That way you have a wire straight from the battery to the starter, no junction boxes to give resistance.

Additionally, there are aftermarket
battery cables for generic replacement, I've never seen one of those with
more than one cable either.

Probably because you're replacing just one of them.

Just because you only have one cable, doesn't
mean that the starter, etc can't be connected, it's just wire. There are
many ways it can be connected and routed, there is no reason more than one
cable needs to go to the battery.

As above, resistance. And of course you don't need a junction box which needs to be mounted somewhere and thoroughly insulated from the chassis. In my current car, the battery is mounted right next to the fusebox. A wire goes from the battery to that, to supply power to lights, etc, etc. The starter is about 2 feet from the battery, diagonally below it and under the engine - another wire goes to that. The alternator is on the other side of the engine, a third wire goes to that. It would be pointless to join these anywhere other than the battery terminal itself - why would you want to do that? To save a tiny bit of wire at the expense of having a junction box providing resistance and taking up space?!

Or that cars use the resistance of the large gage cable to measure current. You just pulled that one from your ass, it's rather unlikely for some obvious reasons. But hey, you claim that's how it's done, provide some references.......

I do hate it when people say "for obvious reasons" - they are never obvious to anyone else.

Pity about that.

It makes your post pointless as you're not conveying your meaning.

That is precisely how you measure current, by a voltage drop across a known resistance. And they certainly don't want to add more resistance to something trying to carry 100s of amps. I guess they could also use an amp clamp, but that would cost more.

On Sun, 23 Jun 2019 19:25:49 +0100, Rod Speed wrote:



"trader_4" wrote in message
...
On Saturday, June 22, 2019 at 3:55:09 PM UTC-4, Commander Kinsey wrote:
On Sat, 22 Jun 2019 20:44:15 +0100, trader_4
wrote:

On Saturday, June 22, 2019 at 3:06:28 PM UTC-4, Rod Speed wrote:
"Commander Kinsey" wrote in message
news On Sat, 22 Jun 2019 15:28:21 +0100, trader_4
wrote:

On Friday, June 21, 2019 at 6:48:31 PM UTC-4,
wrote:
On Fri, 21 Jun 2019 23:15:21 +0100, "Commander Kinsey"
wrote:

On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian

wrote:

On 21/06/2019 21:19, Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know
when
to
switch to trickle charge? I can understand it noticing a drop
in
charging current if the battery is on its own, but what if a
random
changing load is connected, as there is in a running car?

The voltage perhaps.

Why would the voltage change? That's determined by the
alternator or
charger. Let's say the charger/alternator gives out 14.4V
initially,
to charge the battery quickly. It'll just sit at 14.4V forever,
providing the charger can give out enough current to charge the
slightly flat battery and power any connected loads. If the
battery
had no loads connected, it would take a lot less current when it
became
full, but the voltage would stay the same. If the charger
monitored
the current it was providing, how does it know if the battery is
still
charging at 10 amps, or if the battery is full and there's a 10
amp
load?

Not really true with anything but the most primative regulator
like
you might see on an old outboard. Voltage is regulated somewhere
between 13.x and 14.x, not just reflecting what the alternator can
do
against the load.
Rod is right, they look at current from the alternator

Every car I've seen, the the alternator, the battery and the
rest of the car are tied to one point and there is no monitor
for what current is going to the battery vs to the car load.
And Rod is talking computers,
so how did cars work prior to the 80s? They didn't have a computer
didn't monitor anything other than the voltage regulator maintained
a constant voltage of ~14v while the car was running. It was that
way from the early days and auto batteries charged fine.

There may be some modern cars where they do monitor the current
going
to the battery, maybe to save energy and increase fuel consumption,
but it's not necessary to keeping the battery charged.

I doubt it saves much energy. Charging a lead acid at 13.8 to 14.4V
continuously, wastes **** all power. More likely it can charge at a
higher voltage to begin with to make the battery full quickly, then
pull
back to trickle when needed. Handy if you make a habit of using a
lot of
accessories like lights when the engine is off then need it charged
quickly when you drive for 10 minutes. Or if like me you drive for
100
yards at a time and are using the starter a lot (or have one of
those stop
start engines). Older cars would run out of battery if you did lots
of
short journeys, as there was no fast charge.

There is nothing they can do about the load so they don't give a
****
about the
lights. The regulator just watches alternator current and cranks
up
the voltage to keep it up.

That's rather bizarre. The alternator monitors current? So,
what's
the correct current that it's targeting? 2 amps, 20 amps? 70
amps?
The current depends on what loads are on and the alternator doesn't
know that. Seems to me it keeps the system VOLTAGE at ~14V and
that
has worked for 100 years.

It would have to monitor the current going into the battery, by
having at
least two ammeters,

Just two cables from the battery positive terminal, one to the
alternator
and one
to the rest of the electrical system and measure the voltage drop over
those.

or have all the positive wires join somewhere

They do, the positive terminal of the battery.

and measure the branch off to the battery.

Just subtract the current to the rest of the electrical system
from the current going from the alternator to the battery
terminal. That gives you the current going into the battery.

When you have an actual credible cite that describes this alleged
system, post it. Until then, all you are doing is making crap up on the
fly.

I can believe him, I've observed my car's alternator change from 14.4V to
13.8V after it's been running for a bit, so it must know the battery is
full.

Like claiming that all cars have more than one wire to the battery
positive terminal.

I've never seen one that doesn't. Usually I see one for the alternator,
one for the starter, and one for everything else. Why would you have
only one? These are high currents, best to connect things directly.

Well, wherever you are, cars must be put together differently. I've
worked
on American cars, BMW, Mercedes, none had anything more than one cable
to the positive battery terminal. Additionally, there are aftermarket
battery cables for generic replacement, I've never seen one of those with
more than one cable either. Just because you only have one cable, doesn't
mean that the starter, etc can't be connected, it's just wire. There are
many ways it can be connected and routed, there is no reason more than one
cable needs to go to the battery.

Must be why so many cars have more than one.

Yip - same reason in your house you connect the wire to power your sockets from the fusebox to one socket, then another, then another, you don't have seperate wires going from the fusebox to each socket. That would be utterly pointless. In the car you might aswell use the battery terminal as the junction box. That way everything has the full battery voltage only one cable away.

On Sun, 23 Jun 2019 17:53:21 +0100, trader_4 wrote:

On Sunday, June 23, 2019 at 12:27:13 PM UTC-4, TMS320 wrote:
On 22/06/2019 22:58, Commander Kinsey wrote:
On Sat, 22 Jun 2019 17:03:08 +0100, TMS320 wrote:
On 21/06/2019 21:19, Commander Kinsey wrote:

How does a lead acid battery charger (or car alternator) know when to
switch to trickle charge?

It doesn't.

Mine does, if I start my car when the battery is say 80% full, the
voltage will be 14.4V. After a while, something causes that voltage to
drop to 13.8, because something knows the battery is full and should no
longer be charged at a high rate.

I can understand it noticing a drop in
charging current if the battery is on its own, but what if a random
changing load is connected, as there is in a running car?

Ohm's law.

Explain how an alternator or charger can use ohm's law to distinguish
between:

To determine current, measure the voltage across a series resistor, duh.

1) A car battery which is full, with a load of 10 amps connected to it,
like two headlights.
2) A car battery with no load, which is not full yet and draws 10 amps
for the charge.

Two resistors?

The issue is not how it can be measured, the question is if any cars
actually do it, ie measure the current flowing into the battery and
use it to control the alternator. I've never seen it, never heard of
it. So far, all we have is Rod's flapping gums and he's made all kinds
of false claims and lies here.

And my claim that my car's alternator drops from 144V to 13.8V when the battery becomes full.

And he said they don't use a resistor,
that they just use the resistance of the battery cable. That doesn't
make sense to us, for obvious reasons. So, we're still waiting for
Rod to show us some documentation of what he claims cars do......

You do realise wires have resistance?

On Sun, 23 Jun 2019 17:27:09 +0100, TMS320 wrote:

On 22/06/2019 22:58, Commander Kinsey wrote:
On Sat, 22 Jun 2019 17:03:08 +0100, TMS320 wrote:
On 21/06/2019 21:19, Commander Kinsey wrote:

How does a lead acid battery charger (or car alternator) know when to
switch to trickle charge?

It doesn't.

Mine does, if I start my car when the battery is say 80% full, the
voltage will be 14.4V. After a while, something causes that voltage to
drop to 13.8, because something knows the battery is full and should no
longer be charged at a high rate.

I can understand it noticing a drop in
charging current if the battery is on its own, but what if a random
changing load is connected, as there is in a running car?

Ohm's law.

Explain how an alternator or charger can use ohm's law to distinguish
between:

To determine current, measure the voltage across a series resistor, duh.

Why didn't you wait until I'd finished?

1) A car battery which is full, with a load of 10 amps connected to it,
like two headlights.
2) A car battery with no load, which is not full yet and draws 10 amps
for the charge.

Two resistors?

Yes that would work, but not if it has no external sensors (as in external to the alternator).

On Fri, 21 Jun 2019 13:48:56 -0700, % wrote:

On 2019-06-21 1:19 p.m., Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know when to
switch to trickle charge?* I can understand it noticing a drop in
charging current if the battery is on its own, but what if a random
changing load is connected, as there is in a running car?

the catalytic converter tells it
I can tell you how an alternator does it, chargerscan do it
differently. AN alternator doesn't "switch to trickle charge". AN
alternator limits the output voltage. A battery will only accept a
certain amount of charge at any voltage. At 14.6 volts it basically
stops taking a charge. The regulator is set to limit the voltage to a
specified voltage - 13.8 or 14.2, or something similar. An alternator
is intrinsically current limitted so will not provide more than the
rated current, If the battery open circuit voltage is below 12 volts
it will tale pretty close to whatever the alternator can put out, as
the open circuit voltage increases, the amount of charge it will
accept decreases, untill at 14.6 volts or whatever is designed as full
charge, it will no longer accept ANY charge. As the load changes, the
alternator provides more or less current as required to maintain the
fully charged voltage.

Clear as mud???

On Sat, 22 Jun 2019 16:03:07 -0500, Mark Lloyd
wrote:

On 6/21/19 5:55 PM, Commander Kinsey wrote:

[snip]

I guess charging a car battery with a charger plugged into the house
won't work if you have a load in the car like lights (or in my case a
faulty alarm).* The charger will think the battery is still drawing a
fair current and isn't full, when in fact it's the load eating it up.

I've tried it with an automatic charger. If the load is enough that the
battery won't change within a certain time, the charger stops and
indicates an error.

[snip]
That's just with "smart chargers" I've had 3 and they both ended up
"brain dead" and would report a shorted cell on a perfectly good
battery.

On Sun, 23 Jun 2019 12:04:19 +1000, Xeno
wrote:

On 23/6/19 1:45 am, Rod Speed wrote:


"trader_4" wrote in message
...
On Friday, June 21, 2019 at 6:48:31 PM UTC-4, wrote:
On Fri, 21 Jun 2019 23:15:21 +0100, "Commander Kinsey"
wrote:

On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian
wrote:

On 21/06/2019 21:19, Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know
when to
switch to trickle charge?* I can understand it noticing a drop in
charging current if the battery is on its own, but what if a random
changing load is connected, as there is in a running car?

The voltage perhaps.

Why would the voltage change?* That's determined by the alternator
or charger.* Let's say the charger/alternator gives out 14.4V
initially, to charge the battery quickly.* It'll just sit at 14.4V
forever, providing the charger can give out enough current to charge
the slightly flat battery and power any connected loads.* If the
battery had no loads connected, it would take a lot less current
when it became full, but the voltage would stay the same.* If the
charger monitored the current it was providing, how does it know if
the battery is still charging at 10 amps, or if the battery is full
and there's a 10 amp load?

Not really true with anything but the most primative regulator like
you might see on an old outboard. Voltage is regulated somewhere
between 13.x and 14.x, not just reflecting what the alternator can do
against the load.
Rod is right, they look at current from the alternator

Every car I've seen, the the alternator, the battery
and the rest of the car are tied to one point

But there is normally more than the one wire
at the the positive terminal of the battery.

Parallel circuits, so what?

and there is no monitor for what current
is going to the battery vs to the car load.

Wrong when there is normally more than the one
wire at the the positive terminal of the battery.

And Rod is talking computers,

Because that’s what his car has.

so how did cars work prior to the 80s?

The regulator uses the voltage it sees which varys
with the load and the charge of the battery.

They didn't have a computer didn't monitor anything
other than the voltage regulator maintained a constant
voltage of ~14v while the car was running.

Its more complicated than that with the voltage.

No it isn't.

It was that way from the early days and auto batteries charged fine.

Generators do it differently to alternators and we arent discussing
whether they charged fine or not, we are discussing what the
regulator does when the battery is fully charged so that it doesn’t
boil off the water in the battery. That’s particularly important
now that most car batterys arent refillable with water anymore.

There may be some modern cars where they do monitor the current going
to the battery, maybe to save energy and increase fuel consumption,

It actually to avoid ****ing the battery by delivering
the same current to the battery when its fully charged.

but it's not necessary to keeping the battery charged.

That isnt what is being discussed either.

There is nothing they can do about the load so they don't
give a **** about the lights.* The regulator just watches
alternator current and cranks up the voltage to keep it up.

That's rather bizarre.* The alternator monitors current?* So, what's
the correct current that it's targeting?* 2 amps, 20 amps?* 70 amps?
The current depends on what loads are on and the alternator doesn't
know that.* Seems to me it keeps the system VOLTAGE at ~14V

No it doesn’t. Doing that would overcharge a fully charged battery.

and that has worked for 100 years.

Wrong again, generators do it differently to alternators.

Yes, no argument there. You mean like this;
http://mgaguru.com/mgtech/books/pdf/..._Box_Tests.pdf

Voltage and current control. They were pretty much on the way out by the
time I finished my apprenticeship.

With alternators, voltage is key.

You need to get with the times. Generators went out with button up boots.
A generator generally used a "3 unit regulator" Onewas the cut-out -
which is replaced by the diodes in an alternator. The alternator
cannot drain the battery attempting to "motor" itself like a
generator. The second unit was the current regulator, because a
generator is NOT self limitting. If you full feild a generator into a
dead short it will melt itesrlf down.

An alternator is self limiting due to it's higher stator resistance.It
will ONLY put out a certain amount of current into a load, regardless
of the resistance of the load. This is due to both the stator
resistance and the maximum flux of the rotor - so the current
regulator (actually "limitter" as it only controls the maximum output)
is not required on an alternator either. This leaves the voltage
regulator, which controls the feild current either linearly or by
"chopping" - or pulse width modulation. The more current flowing in
the feild the higher power produced - in volt-amps. As the current
changes, the voltage changes in reverse, for the same feild strength.
Higher current = lower voltage. By sensing and controlling the voltage
the current pretty much looks after itself - as the regulator
controlls the feild strenth by varying the feild current. It controls
the feild current by controlling the voltage impressed across the
feild coil.. As the engine speeds up, it requires less feild strength
to produce the same voltage.