Here, educate yourself;
https://www.swtc.edu/ag_power/electr...l_circuits.htm

I knew all that before you were even born, thanks.

so it is still a load even when fully charged.

Not when its still taking 4A,

If the battery is *taking* 4 amps, then it *is definitely the load*.

But it wont be taking 4A WHEN THE BATTERY IS OUT OF THE
CAR WITH A BENCH SUPPLY. Because the battery voltage will
have risen once it has been charged so the original 4A will
have dropped significantly WITH A BENCH SUPPLY.

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

It has more than one wire to the positive terminal of the battery.
So it can see what current is going to the rest of the car.

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.

Not when there is more than one wire going to the
positive terminal of the battery, and there always is.

No they aren't, unless one has been added.


--
Bod

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

On Sun, 23 Jun 2019 01:30:41 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

FLUSH another 209 !!! lines of senile bull**** unread again

--
Sqwertz to Rodent Speed:
"This is just a hunch, but I'm betting you're kinda an argumentative
asshole.
MID:

Modern car alternators seem to be able to give out a huge amount of current at engine idle speed. I'm sure my friend got his to give out pretty much the full 80 amps without revving the engine. He was powering a small disco on a campsite :-)


On Sat, 22 Jun 2019 11:00:34 +0100, Brian Gaff wrote:

Yes indeed, the nominal output of an alternator can be as high as 15 volts,
but even a fully charged car battery is only 13.8v as far as I know and
these days, I'm sure the direction of current flow and voltages are
monitored very well by the computers. In the old days it was a bit of a
black art just relying on the ability of the alternator or dynamo in the old
bangers.
Normally the output will change due to engine speed, but in alternators
there is a voltage regulator inbuilt to keep the thing pretty nominal and
of course the thing that then suffers is the charging rate, ie its going to
be be slower when its not running very fast. I think if a battery dips below
about 11v outside of starter transients, you have to charge it or get a new
one. This very accurate sensing these days can often mask a battery on its
last legs though, as people tend to ignore warnings if the car still works,
then they leave it a couple of days and it won't start!

Brian

On Sat, 22 Jun 2019 11:11:33 +0100, Rod Speed wrote:

Brian Gaff wrote

Yes indeed, the nominal output of an alternator can be as high as 15
volts, but even a fully charged car battery is only 13.8v as far as I know

They are a bit higher than that just after being charged.

Depends what voltage you were charging them with. 13.8V is the recommended voltage for a continuous charge. 14.4V for fast, and 15V for very fast. But the last two need to be stopped before boil over.

I used to have a home made solar array, with thirty old car batteries in parallel. Bad idea. One of the batteries died - it lost a cell. The other batteries immediately then charged it very quickly as it was 10V and they were 12V, and evaporated the other cells one by one. There was eventually an explosion and the battery was blasted across the garage in several pieces, with a bloody strong smell of rotten eggs.

and these days, I'm sure the direction of current flow and voltages are
monitored very well by the computers. In the old days it was a bit of a
black art just relying on the ability of the alternator or dynamo in the
old bangers.
Normally the output will change due to engine speed, but in alternators
there is a voltage regulator inbuilt to keep the thing pretty nominal
and of course the thing that then suffers is the charging rate, ie its
going to be be slower when its not running very fast. I think if a battery
dips below about 11v outside of starter transients, you have to charge it
or get a new one. This very accurate sensing these days can often mask a
battery on its last legs though, as people tend to ignore warnings if the
car still works, then they leave it a couple of days and it won't start!

Brian

--
----- --
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Rod Speed" wrote in message
...
Commander Kinsey wrote

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

From the current the battery takes.

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?

You just look at the current going to the battery. The variably
loads like with lights isnt supplied by the battery when the
engine is running, its supplied by the alternator.

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.

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:
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.

On Sat, 22 Jun 2019 00:57:57 +0100, 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.

I can if the charger / power supply is powerful enough.

The battery then chooses how much current is drawn.

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

Correct, it's the current it checks.

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.

No, it LIMITS the current. I set 13.8V, 2.5A. It will back off if either is exceeded.

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.

The faulty frog car with the dodgy alarm.

On Sat, 22 Jun 2019 11:41:15 +0100, 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.

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.

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. 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.

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.

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.

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.

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.

Commander Kinsey wrote
Rod Speed wrote
Brian Gaff wrote

Yes indeed, the nominal output of an alternator can be as high as 15
volts, but even a fully charged car battery is only 13.8v as far as I
know

They are a bit higher than that just after being charged.

Depends what voltage you were charging them with.

We're discussing cars.

13.8V is the recommended voltage for a continuous charge.

That's wrong too.

14.4V for fast, and 15V for very fast.

And so is that.

But the last two need to be stopped before boil over.

I used to have a home made solar array, with thirty old car batteries in
parallel. Bad idea. One of the batteries died - it lost a cell. The
other batteries immediately then charged it very quickly as it was 10V and
they were 12V, and evaporated the other cells one by one.

Trivially easy to avoid that.

There was eventually an explosion

That was the hydrogen you stupidly didn't get rid of.

and the battery was blasted across the garage in several pieces, with a
bloody strong smell of rotten eggs.

and these days, I'm sure the direction of current flow and voltages are
monitored very well by the computers. In the old days it was a bit of a
black art just relying on the ability of the alternator or dynamo in the
old bangers.
Normally the output will change due to engine speed, but in alternators
there is a voltage regulator inbuilt to keep the thing pretty nominal
and of course the thing that then suffers is the charging rate, ie its
going to be be slower when its not running very fast. I think if a
battery
dips below about 11v outside of starter transients, you have to charge
it
or get a new one. This very accurate sensing these days can often mask
a
battery on its last legs though, as people tend to ignore warnings if
the
car still works, then they leave it a couple of days and it won't start!

Brian

--
----- --
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Rod Speed" wrote in message
...
Commander Kinsey wrote

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

From the current the battery takes.

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?

You just look at the current going to the battery. The variably
loads like with lights isnt supplied by the battery when the
engine is running, its supplied by the alternator.

On 23/6/19 1:30 am, Rod Speed wrote:


"Xeno" wrote in message
...
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 charged 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.

That isnt what was being discussed there. What was being discussed
there was charging the battery out of the car with a bench supply.

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.

None of that is relevant to what was being discussed there,
charging the battery out of the car with a bench supply.

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?

With a BENCH SUPPLY, it continues to provide the
same voltage as it did with the battery connected.

It should, if designed correctly, shut down since it no longer sees a
load. Otherwise it may destroy itself.

That is just plain wrong with a BENCH SUPPLY.
None of those destroy themselves with no load.

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.

We're discussing a normal car battery in a steaming turd with
wheels frog car.

Also, my bench charger

We arent discussing a bench charger, we are discussing a bench SUPPLY.

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*.

So that is nothing like the situation being discussed
with a BENCH SUPPLY which is still delivering 4A to
a battery that has been removed from the car.

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

Irrelevant to what is being discussed, 4A isnt a trickle charge.

The car alternator regulator is no different.

We arent discussing that there.

It sees the battery as a load, determines the voltage reference and
pumps up its output. When the regulator sees the battery voltage at
the peak setpoint, it too will drop the current to a trickle. 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.

All irrelevant to charging a battery out of the car with a BENCH SUPPLY.

Here, educate yourself;
https://www.swtc.edu/ag_power/electr...l_circuits.htm

I knew all that before you were even born, thanks.

so it is still a load even when fully charged.

Not when its still taking 4A,

If the battery is *taking* 4 amps, then it *is definitely the load*.

But it wont be taking 4A WHEN THE BATTERY IS OUT OF THE
CAR WITH A BENCH SUPPLY. Because the battery voltage will
have risen once it has been charged so the original 4A will
have dropped significantly WITH A BENCH SUPPLY.

If you have a battery connected to a bench supply, it is still the load
because it will always be taking *some* current. If it is taking 4 amps
it is definitely loading the BENCH SUPPLY.

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

It has more than one wire to the positive terminal of the battery.
So it can see what current is going to the rest of the car.

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.

Not when there is more than one wire going to the
positive terminal of the battery, and there always is.




--

Xeno


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

On 23/6/19 2:03 am, 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.

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.


That's a bit *deep* for some people to comprehend.

--

Xeno


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

"Xeno" wrote in message
...
On 23/6/19 1:30 am, Rod Speed wrote:


"Xeno" wrote in message
...
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 charged 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.

That isnt what was being discussed there. What was being discussed
there was charging the battery out of the car with a bench supply.

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.

None of that is relevant to what was being discussed there,
charging the battery out of the car with a bench supply.

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?

With a BENCH SUPPLY, it continues to provide the
same voltage as it did with the battery connected.

It should, if designed correctly, shut down since it no longer sees a
load. Otherwise it may destroy itself.

That is just plain wrong with a BENCH SUPPLY.
None of those destroy themselves with no load.

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.

We're discussing a normal car battery in a steaming turd with
wheels frog car.

Also, my bench charger

We arent discussing a bench charger, we are discussing a bench SUPPLY.

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*.

So that is nothing like the situation being discussed
with a BENCH SUPPLY which is still delivering 4A to
a battery that has been removed from the car.

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

Irrelevant to what is being discussed, 4A isnt a trickle charge.

The car alternator regulator is no different.

We arent discussing that there.

It sees the battery as a load, determines the voltage reference and
pumps up its output. When the regulator sees the battery voltage at the
peak setpoint, it too will drop the current to a trickle. 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.

All irrelevant to charging a battery out of the car with a BENCH SUPPLY.

Here, educate yourself;
https://www.swtc.edu/ag_power/electr...l_circuits.htm

I knew all that before you were even born, thanks.

so it is still a load even when fully charged.

Not when its still taking 4A,

If the battery is *taking* 4 amps, then it *is definitely the load*.

But it wont be taking 4A WHEN THE BATTERY IS OUT OF THE
CAR WITH A BENCH SUPPLY. Because the battery voltage will
have risen once it has been charged so the original 4A will
have dropped significantly WITH A BENCH SUPPLY.

If you have a battery connected to a bench supply, it is still the load
because it will always be taking *some* current. If it is taking 4 amps it
is definitely loading the BENCH SUPPLY.

It wont be taking 4A when charged unless
you have completely ****ed up the voltage.

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

It has more than one wire to the positive terminal of the battery.
So it can see what current is going to the rest of the car.

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.

Not when there is more than one wire going to the
positive terminal of the battery, and there always is.

On 23/6/19 5:47 am, Commander Kinsey wrote:
Modern car alternators seem to be able to give out a huge amount of
current at engine idle speed.* I'm sure my friend got his to give out
pretty much the full 80 amps without revving the engine.* He was
powering a small disco on a campsite :-)

No way to get a full 80 amps out of an alternator *at idle*.


On Sat, 22 Jun 2019 11:00:34 +0100, Brian Gaff
wrote:

Yes indeed, the nominal output of an alternator can be as high as 15
volts,
but even a fully charged car battery is only 13.8v as far as I know and
these days, I'm sure the direction of current flow and voltages are
monitored very well by the computers. In the old days it was a bit of a
black art just relying on the ability of the alternator or dynamo in
the old
bangers.
*Normally the output will change due to engine speed, but* in alternators
there is a voltage regulator inbuilt to keep the* thing pretty
nominal and
of course the thing that then suffers is the charging rate, ie its
going to
be be slower when its not running very fast. I think if a battery dips
below
about 11v outside of starter transients, you have to charge it or get
a new
one. This* very accurate sensing these days can often mask a battery
on its
last legs though, as people tend to ignore* warnings if the car still
works,
then they leave it a couple of days and it won't start!

Brian


--

Xeno


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

On Sun, 23 Jun 2019 10:02:37 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:


We're discussing cars.

We're discussing your and his clinical insanity, whenever one you opens his
stupid perverted gob!

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

On Sun, 23 Jun 2019 16:07:14 +1000, Xeno, another brain damaged,
troll-feeding, senile Australian idiot, blathered:


No way to get a full 80 amps out of an alternator *at idle*.

Every way for him to get YOU to suck him off time and again, every time he
wants to be sucked off by one of you seniles infesting these groups! BG

On Sun, 23 Jun 2019 12:59:55 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:


It wont be taking 4A when charged unless
you have completely ****ed up the voltage.

You clinically insane auto-contradicting asshole disagree? Well, that's a
novelty! LMAO!

--
Keema Nam addressing nym-shifting senile Rodent:
"You are now exposed as a liar, as well as an ignorant troll."
"MID: .com"

On Sun, 23 Jun 2019 11:57:35 +1000, Xeno, another brain damaged,
troll-feeding, senile Australian idiot, blathered:


If you have a battery

Shove your battery up your arse, that will keep you quiet for a while, you
endlessly blathering senile idiot!

On Sun, 23 Jun 2019 12:59:55 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:


FLUSH another 223 !!! lines of the two senile Ozzie cretin's latest sick
****

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

On Sun, 23 Jun 2019 12:07:05 +1000, Xeno, another brainless, troll-feeding,
senile Australian idiot, blathered:

Ohm's law.

That's a bit *deep* for some people to comprehend.

Like you being unable to comprehend that you've turned into another
miserable troll-feeding brainless senile asshole? BG

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)

"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"!

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

"I am proud of being nicked 10 times, and even prouder of talking my
way out of twice that number of offences".
"Make that 12. 9 speeding offences, 2 seatbelts, and 1 unroadworthy
vehicle".

On rape:
"What is wrong is raping someone. It doesn't matter if they are an
adult or a child".
"The problem there is our prudishness. People ought to have sex with
everyone all the time".

On Jimmy Savile:
"If he had done it against their will, they would have come forwards
earlier. The fact that they didn't suggests either he did nothing at
all, or the children liked it".

"Journalists are not human".

"I don't give a **** about the law".
"**** the law".
"It's only illegal is you get caught".
"Something being illegal does not matter".
"The law is irrelevant".

"I am honest".
"Theft is illegal".
"When I was 11 I stole candles from a church".

"I have never found out the purpose of underpants".

"Women are inferior".
"Crying is unnecessary and pathetic. So is screaming. Why do women
scream when they're frightened? Perhaps they realise they're
inferior and are calling for the nearest man"?

"I believe that UFOs have visited us but not in recent times".
"I don't believe in UFOs".
"When someone says "UFO", they do not mean 4000 years ago. Then they
would just be "FO" as they hadn't invented flying yet".

"My IQ is superiour to that of most people".
"I am inferior in some ways but superior in other ways".
"I admit I should not have been born".
"Jobs are for sheeple".

"Some men are hot".

"I can sleep outside in a temperature of -20C wearing only shorts".

"I once took a dump behind some bushes and slid down a hill to wipe my
arse".

"I do not post waffling bull**** or childish insults".
"He is indeed very stupid, and easy to make fun of".

"I am currently eating a sandwich made with bread that has been in my
fridge THREE WEEKS past the sell by date. It is not dry, it is not
mouldy, it is identical to the day I bought it".

"And there's nothing wrong with jumping red lights if you don't cause
an accident"

"I don't want to drive at the speed limit. It's absurdly slow and in
fact I find it more dangerous. It's so tedious I'm in danger of
falling asleep. "Whoever made up the limits must have a really slow
brain". "I think it's stupid to follow a law which is baseless. The
law on red lights is to stop you hitting someone. If there is
nobody there, you cannot hit them".

"If the guy behind me has his lights on too bright. I let him past
then tailgate him with my full beam on until he switches his off".

"I like driving fast and scaring people".

"People who don't know how to shave don't know how to behave."

On mental health:
"Being sectioned just means you are different from others, it doesn't
mean you are wrong".

"If I wanted you to stab me with a knife and kill me, you should not
get into trouble for it".
"I would kill my sister if I thought I'd get away with it".
"I'm not what most people think of as human".

"I have an IQ of 140".
"I am seldom wrong".
"There is no reason the data stored in our heads cannot be
transferred".
"I will not accept money from my neighbours for doing them a favour"
"My neighbour just paid me £40 to brush moss off the roof of her porch
extension. It took me 10 minutes."

"Pain is not harmful. The victim may well want rid of it, but it's no
reason for anyone to rush there".

"Dogs are supposed to live in packs of other dogs, running wild. Not
sat in a house all day".

"We should be allowed to do as we wish within reason. For example":
"Smoke weed in a public place, drive as fast as we like, and do both
of those stark naked. Oh and **** in public".

"Careful drivers tend to get in my way".

"I can only predict two minutes into the future".



Sociopath.
http://www.mcafee.cc/Bin/sb.html
"As I've told you before, that's quite normal. It's just not prim and
proper like you, you silly snob".

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.

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.

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.

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.

*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.

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.
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.


--

Xeno


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

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 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 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

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]

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 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 Sun, 23 Jun 2019 14:53:00 +0100, trader_4 wrote:

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.

No idea where to find that.

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.

Agreed. And it could well have a sensor in the fusebox etc.

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.

No, all I did was to start the car when the battery was almost full. The battery terminal voltage was immediately 14.4V. 20 minutes later it dropped to 13.8V. I added no loads. I think it actually dropped gradually if that means anything. I actually did that test because someone in one of these groups (although some troll has deleted half the groups, so I've added them back in AGAIN) told me that a car alternator changes voltage, this was in a post 6 months ago.

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.

It could only be mV, but easy enough to sense with modern electronics. Or how about an amp clamp?

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.

Every UK car has 2 or 3 cables on the battery positive. America is infamous for being behind the times. We all know your cars can't go round corners, and get way less HP for the same engine size.

Why doesn't someone show us
an example, a description of one of these alleged fancy voltage regulators
that are computer controlled?

On 23/06/2019 23:55, Commander Kinsey wrote:
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?

You asked.

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).

An alternator is not simply two wire power output. The electronics on
the alternator would be to keep everything within acceptable parameters
but fine control comes from the ECU.

On Mon, 24 Jun 2019 16:33:08 +0100, TMS320 wrote:

On 23/06/2019 23:55, Commander Kinsey wrote:
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?

You asked.

No, I said "explain.... distinguish between:" and before I'd listed the two things, you interrupted.

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).

An alternator is not simply two wire power output. The electronics on
the alternator would be to keep everything within acceptable parameters
but fine control comes from the ECU.

So there are external sensors.

Commander Kinsey wrote:
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.

You posted them, you freak.
I enjoy taking the **** out of ******s, and you are a ******.

On Mon, 24 Jun 2019 17:36:25 +0100, Mr Pounder Esquire wrote:

Commander Kinsey wrote:
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.

Not admitting to your IQ then?

"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.

You posted them, you freak.
I enjoy taking the **** out of ******s, and you are a ******.

Because I disagree with your illogical beliefs?

On Mon, 24 Jun 2019 16:33:08 +0100, TMS320, yet another brain damaged,
troll-feeding, senile asshole, blathered again:


You asked.

Nope, senile asshole! HE baited, and YOU bit!

On Sun, 23 Jun 2019 03:07:05 +0100, Xeno wrote:

On 23/6/19 2:03 am, 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.

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.

That's a bit *deep* for some people to comprehend.

It's also impossible to use it without having a remote (to the alternator) sensor. It's like my power company telling me if I'm using a kettle or a toaster.

Well I see the full voltage charging a flat battery at idle. Obviously they could be designed to be capable of this and it would be very useful to charge the battery quickly when doing stop start town driving, or driving at minimum revs in top gear in a town.


On Sun, 23 Jun 2019 07:07:14 +0100, Xeno wrote:

On 23/6/19 5:47 am, Commander Kinsey wrote:
Modern car alternators seem to be able to give out a huge amount of
current at engine idle speed. I'm sure my friend got his to give out
pretty much the full 80 amps without revving the engine. He was
powering a small disco on a campsite :-)

No way to get a full 80 amps out of an alternator *at idle*.

On Sat, 22 Jun 2019 11:00:34 +0100, Brian Gaff
wrote:

Yes indeed, the nominal output of an alternator can be as high as 15
volts,
but even a fully charged car battery is only 13.8v as far as I know and
these days, I'm sure the direction of current flow and voltages are
monitored very well by the computers. In the old days it was a bit of a
black art just relying on the ability of the alternator or dynamo in
the old
bangers.
Normally the output will change due to engine speed, but in alternators
there is a voltage regulator inbuilt to keep the thing pretty
nominal and
of course the thing that then suffers is the charging rate, ie its
going to
be be slower when its not running very fast. I think if a battery dips
below
about 11v outside of starter transients, you have to charge it or get
a new
one. This very accurate sensing these days can often mask a battery
on its
last legs though, as people tend to ignore warnings if the car still
works,
then they leave it a couple of days and it won't start!

Brian

Xeno wrote on 22/06/2019 9:03 PM:
On 22/6/19 8:00 pm, Brian Gaff wrote:
Yes indeed, the nominal output of an alternator can be as high as 15
volts,
but even a fully charged car battery is only 13.8v as far as I know and

A 12 Volt lead acid battery will show 13.2 volts straight off the
charger, about 2.2 volts per cell. That will drop to about 12.7 volts
after a day or so, a tad over 2.1 volts per cell.

On the other hand, a vehicle's nominal *system voltage* is 14 Volts.
That's because the *alternator typically operates in the 13.8-14.2 range.

Due to increasing loads on vehicle electrical equipment, manufacturers
were pushing to a nominal 42 Volt electrical system on cars. They were
to be equipped with a 36 Volt battery. It may not happen now.
https://en.wikipedia.org/wiki/42-volt_electrical_system

Do Electric Cars have a 'standard' operating voltage?? Or does it vary
from one manufacturer to another??


--
Daniel

On 11/07/2019 10:09, Daniel60 wrote:
Xeno wrote on 22/06/2019 9:03 PM:
On 22/6/19 8:00 pm, Brian Gaff wrote:
Yes indeed, the nominal output of an alternator can be as high as 15
volts,
but even a fully charged car battery is only 13.8v as far as I know and

A 12 Volt lead acid battery will show 13.2 volts straight off the
charger, about 2.2 volts per cell. That will drop to about 12.7 volts
after a day or so, a tad over 2.1 volts per cell.

On the other hand, a vehicle's nominal *system voltage* is 14 Volts.
That's because the *alternator typically operates in the 13.8-14.2 range.

Due to increasing loads on vehicle electrical equipment, manufacturers
were pushing to a nominal 42 Volt electrical system on cars. They were
to be equipped with a 36 Volt battery. It may not happen now.
https://en.wikipedia.org/wiki/42-volt_electrical_system

Do Electric Cars have a 'standard' operating voltage?? Or does it vary
from one manufacturer to another??


There would be no reason to have a standard voltage - standard charge
voltage, yes. 230 single phase or 400 three phase (same thing)

A far as battery voltages go - looking at say 200bhp (around 260Kw) is
around 660A at 400V.

which is still a lot of amps. I'd say the ideal is probably near the
limit of *cheap* semiconductor power FETS probably around 1kv or so.

I am a long time out of that field though, so it may be higher.

What I am fairly sure of however is that battery voltage will be decided
by cost of using that particular voltage and that will be down to what
semiconductors are available.

Should the market develop towards standardised batteries that could be
replaced by a local kwikfit etc, then I am sure manufacturers would
develop a common standard.


--
The biggest threat to humanity comes from socialism, which has utterly
diverted our attention away from what really matters to our existential
survival, to indulging in navel gazing and faux moral investigations
into what the world ought to be, whilst we fail utterly to deal with
what it actually is.

On 11/7/19 5:11 am, Commander Kinsey wrote:
Well I see the full voltage charging a flat battery at idle.* Obviously
they could be designed to be capable of this and it would be very useful
to charge the battery quickly when doing stop start town driving, or
driving at minimum revs in top gear in a town.

You may see a high voltage but you will not see a high current at idle.
The alternator is not *capable* of high current at idle.



On Sun, 23 Jun 2019 07:07:14 +0100, Xeno wrote:

On 23/6/19 5:47 am, Commander Kinsey wrote:
Modern car alternators seem to be able to give out a huge amount of
current at engine idle speed.* I'm sure my friend got his to give out
pretty much the full 80 amps without revving the engine.* He was
powering a small disco on a campsite :-)

No way to get a full 80 amps out of an alternator *at idle*.

On Sat, 22 Jun 2019 11:00:34 +0100, Brian Gaff
wrote:

Yes indeed, the nominal output of an alternator can be as high as 15
volts,
but even a fully charged car battery is only 13.8v as far as I know and
these days, I'm sure the direction of current flow and voltages are
monitored very well by the computers. In the old days it was a bit of a
black art just relying on the ability of the alternator or dynamo in
the old
bangers.
*Normally the output will change due to engine speed, but* in
alternators
there is a voltage regulator inbuilt to keep the* thing pretty
nominal and
of course the thing that then suffers is the charging rate, ie its
going to
be be slower when its not running very fast. I think if a battery dips
below
about 11v outside of starter transients, you have to charge it or get
a new
one. This* very accurate sensing these days can often mask a battery
on its
last legs though, as people tend to ignore* warnings if the car still
works,
then they leave it a couple of days and it won't start!

Brian



--

Xeno


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