The charger says it's running at about 3 amps. When can I consider the
battery properly charged?

The manual for the charger is unhelpfully vague, merely saying in poor
English that when the pointer is "in the left part of" the scale that
charging is complete.

Daniele

On Fri, 9 Oct 2009 13:40:27 +0100 someone who may be
(D.M. Procida) wrote
this:-

The charger says it's running at about 3 amps. When can I consider the
battery properly charged?

Lead-acid batteries are best left being trickle charged. Of course
that implies that the charger is capable of doing that, which many
cheap ones are not.






--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000...#pt3-pb3-l1g54

"David Hansen" wrote in message
...
On Fri, 9 Oct 2009 13:40:27 +0100 someone who may be
(D.M. Procida) wrote
this:-

The charger says it's running at about 3 amps. When can I consider the
battery properly charged?

Lead-acid batteries are best left being trickle charged. Of course
that implies that the charger is capable of doing that, which many
cheap ones are not.


Ouch no!! That's the best way of wrecking a lead acid battery, especially
if the sealed types. Any current after it's fully charged will dry out a
battery.

The best charger has always been a constant voltage charger. This matter
has been discussed ad nauseum before in the NG.

On Fri, 9 Oct 2009 15:05:18 +0100 someone who may be "Fredxx"
wrote this:-

Lead-acid batteries are best left being trickle charged. Of course
that implies that the charger is capable of doing that, which many
cheap ones are not.

Ouch no!! That's the best way of wrecking a lead acid battery, especially
if the sealed types. Any current after it's fully charged will dry out a
battery.

I have been charging a set of sealed lead acid batteries in that way
for the best part of a decade. So far they remain fine. Obviously if
the charging voltage is set too high then it would indeed dry out
the battery, but I did a lot of research before deciding on that
form of charging to get the charging voltage right.

http://www.atbatt.com/sku_pdf/cyclon_application_manual.pdf



--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000...#pt3-pb3-l1g54

"David Hansen" wrote in message
...
On Fri, 9 Oct 2009 15:05:18 +0100 someone who may be "Fredxx"
wrote this:-

Lead-acid batteries are best left being trickle charged. Of course
that implies that the charger is capable of doing that, which many
cheap ones are not.

Ouch no!! That's the best way of wrecking a lead acid battery, especially
if the sealed types. Any current after it's fully charged will dry out a
battery.

I have been charging a set of sealed lead acid batteries in that way
for the best part of a decade. So far they remain fine. Obviously if
the charging voltage is set too high then it would indeed dry out
the battery, but I did a lot of research before deciding on that
form of charging to get the charging voltage right.

http://www.atbatt.com/sku_pdf/cyclon_application_manual.pdf



I can't see any mention of trickle charging. Float charging and constant
voltage charging are all that are mentioned or recommended.

You mix "trickle charging" with "charging voltage" in the same paragraph,
which suggests that your success in charging lead acid batteries has perhaps
been more by accident rather than through knowledge.

On Fri, 9 Oct 2009 18:08:09 +0100 someone who may be "Fredxx"
wrote this:-

You mix "trickle charging" with "charging voltage" in the same paragraph,

An assertion which is not correct as far as I can see from a quick
skim, but it is not worth any more than a quick skim. However, even
if I have done so there is nothing wrong with that if done properly.
Paragraphs are not limited to one concept, at least in writing
intended for people who can read more than a newspaper.

which suggests that your success in charging lead acid batteries has perhaps
been more by accident rather than through knowledge.

Which suggests that more work on comprehension of English is
necessary.

By the way, your other assertions indicate a certain level of
knowledge, but one which repeats some commonly held "truths" which
were overtaken by better knowledge some time ago.

I'll keep charging the lead acid batteries concerned (which are a
little different to the car batteries which the OP mentioned after
my posting) in the way I have been. They are coming up to their
estimated lifespan soon. When they do start to be less effective I
will charge their replacements in the same way.

You will probably want the last word.



--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000...#pt3-pb3-l1g54

On 9 Oct, 17:16, David Hansen wrote:

I have been charging a set of sealed lead acid batteries in that way
for the best part of a decade. So far they remain fine.

Then you've been float charging, not trickle charging. The difference
is fractions of a Volt.

Fredxx wrote:
"David Hansen" wrote in message
...
On Fri, 9 Oct 2009 13:40:27 +0100 someone who may be
(D.M. Procida) wrote
this:-

The charger says it's running at about 3 amps. When can I consider the
battery properly charged?
Lead-acid batteries are best left being trickle charged. Of course
that implies that the charger is capable of doing that, which many
cheap ones are not.


Ouch no!! That's the best way of wrecking a lead acid battery, especially
if the sealed types. Any current after it's fully charged will dry out a
battery.

The best charger has always been a constant voltage charger. This matter
has been discussed ad nauseum before in the NG.

I am going to take one of our two cars off the road at the end of this
month. I had thought of running a mains extension under the bonnet and
leaving a charger there. The extension will be plugged into a timer to
control how long the chargers is on.

How long a time should I power up the charger, per day/week?

Dave

"Dave" wrote in message
...
Fredxx wrote:
"David Hansen" wrote in message
...
On Fri, 9 Oct 2009 13:40:27 +0100 someone who may be
(D.M. Procida) wrote
this:-

The charger says it's running at about 3 amps. When can I consider the
battery properly charged?
Lead-acid batteries are best left being trickle charged. Of course
that implies that the charger is capable of doing that, which many
cheap ones are not.


Ouch no!! That's the best way of wrecking a lead acid battery,
especially if the sealed types. Any current after it's fully charged
will dry out a battery.

The best charger has always been a constant voltage charger. This matter
has been discussed ad nauseum before in the NG.

I am going to take one of our two cars off the road at the end of this
month. I had thought of running a mains extension under the bonnet and
leaving a charger there. The extension will be plugged into a timer to
control how long the chargers is on.

How long a time should I power up the charger, per day/week?

Dave

The trouble is cheap chargers generally wreck batteries if left attached for
long lengths of time. I don't know what's currently on the market. But a
charger designed for "float charging" is one you can permanently leave
connected to the battery.

I have known good lead-acid batteries keep their charge for nearly a year,
but it's rare.

I have seen it suggested that a unconnected battery should be topped up
every 6 weeks. I would disconnect the charger if the terminal voltage gets
much above 14V and then assume the battery is then close to being fully
charged.

In article ,
Fredxx wrote:
I have known good lead-acid batteries keep their charge for nearly a
year, but it's rare.

According to an expert on another group the average lead acid car battery
loses 60% of its charge per month. I'm only quoting this FWIW as it's not
my experience. I have a clever electronic battery tester which works out
the actual capacity and that shows nearer 20% per month.
Of course if the battery is left connected in a modern car, the quiescent
drain may well flatten it in less than a month.

--
*Cover me. I'm changing lanes.

Dave Plowman London SW
To e-mail, change noise into sound.

On 9 Oct, 22:59, "Fredxx" wrote:

I have known good lead-acid batteries keep their charge for nearly a year,
but it's rare.

I've an 8-year old, almost-unused, car battery in the garage (not on a
cold floor). It's checked regularly (hydrometer eye in the top) and re-
charged about twice a year. It still has sufficient power to jump-
start anything that needs it. Funny how long they can last, if not
abused. It _is_ worth looking after them.

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Dave
saying something like:

I am going to take one of our two cars off the road at the end of this
month. I had thought of running a mains extension under the bonnet and
leaving a charger there. The extension will be plugged into a timer to
control how long the chargers is on.

How long a time should I power up the charger, per day/week?

Half an hour per day would be fine. That's exactly what I do on one of
mine. So far, that particular battery's remained good for a couple of
years after being laid up.
An alternative is a decent sized solar panel inside the windscreen and
charging either through the lighter socket or via flyleads to the
disconnected battery. Again, another of my vehicles has just that.

All depends on the battery's self-discharge rate and of course if
anything's slightly draining it on the vehicle.

"Dave" wrote in message
...


I am going to take one of our two cars off the road at the end of this
month. I had thought of running a mains extension under the bonnet and
leaving a charger there. The extension will be plugged into a timer to
control how long the chargers is on.

How long a time should I power up the charger, per day/week?

Dave


I have a boat - that is not used over winter - I have a modern 12V pulse
charger .. I just put it on an overnight charge once a month.
It initially take a couple of amps, but drops very quickly to trickle
charge.

Boat starts no problem come spring.

Far better to keep battery in good nick ... don't keep it permananently
trickle charging, and avoid large current charging form flat, as that can
damage the plates.

On 9 Oct, 15:05, "Fredxx" wrote:

The best [Lead acid] charger has always been a constant voltage charger. *

Agreed, except that the voltage should change, as the battery
accumulates charge. A higher voltage is reasonable into a flat
battery, reducing gradually to the appropriate float charge voltage.
Starting out at the float charge voltage wouldn't get your battery
charged in any sensible timescale.

Note #2 is that this ideal voltage is slightly temperature-sensitive

Note #3 (important) is that float voltage is less than trickle
voltage. Constant trickle use kills batteries, just more slowly.

D.M. Procida wrote:
The charger says it's running at about 3 amps. When can I consider the
battery properly charged?

On some battery chargers - when the amp meter drops to zero (on the old one
that I use anyway)
When the batter hydrometer says so (if you can get at the individual cells)!
When a voltmeter says so!
When any indicator on top of the battery says so - usually turns green (on
the battery on my car at least)!

The manual for the charger is unhelpfully vague, merely saying in poor
English that when the pointer is "in the left part of" the scale that
charging is complete.

Or when you can start the car on a chilly morning using battery power alone.

Cash

On Fri, 9 Oct 2009 13:56:37 +0100
"Cash" wrote:

Or when you can start the car on a chilly morning using battery power alone.

Which is a lot of help if the battery if for a non-vehicle application.
R.

When its terminal voltage is about 13.5 V off load.

In article ,
(D.M. Procida) writes:
The charger says it's running at about 3 amps. When can I consider the
battery properly charged?

When it reaches a certain voltage.
The voltage varies slightly by battery temperature, battery type,
and if this is a cyclic charge (almost certainly what you're doing)
or a standby charge (where it's left permanently connected to the
charger).

If your charger is properly voltage regulated, the charge current
will drop to almost zero when charged. If it's not properly voltage
regulated (and many aren't), the charge current won't drop to zero
ever, and you may wreck the battery by leaving it charging too long.

You also need to be careful about the max charging current, again
depending on battery type. Charging at 1/7th of the battery capacity
is safe with just about any type. Some batteries (e.g. car) can
safely be charged at significantly higher rates. This is the max
current though when the battery is pretty flat. As it charges, the
current will drop.

Since you haven't said exactly what type of battery or charger,
can't be more specific.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Andrew Gabriel wrote:

The charger says it's running at about 3 amps. When can I consider the
battery properly charged?

If your charger is properly voltage regulated, the charge current
will drop to almost zero when charged. If it's not properly voltage
regulated (and many aren't), the charge current won't drop to zero
ever, and you may wreck the battery by leaving it charging too long.

I'm not sure. The instructions warn that it doesn't automatically stop
charging, but the current does diminish as it charges - whether this is
through regulation or the effect of the battery's increasing charge I
don't know.

You also need to be careful about the max charging current, again
depending on battery type. Charging at 1/7th of the battery capacity
is safe with just about any type. Some batteries (e.g. car) can
safely be charged at significantly higher rates. This is the max
current though when the battery is pretty flat. As it charges, the
current will drop.

Since you haven't said exactly what type of battery or charger,
can't be more specific.

It's a car battery.

Daniele

In article ,
(D.M. Procida) writes:
Andrew Gabriel wrote:

The charger says it's running at about 3 amps. When can I consider the
battery properly charged?

If your charger is properly voltage regulated, the charge current
will drop to almost zero when charged. If it's not properly voltage
regulated (and many aren't), the charge current won't drop to zero
ever, and you may wreck the battery by leaving it charging too long.

I'm not sure. The instructions warn that it doesn't automatically stop
charging, but the current does diminish as it charges - whether this is
through regulation or the effect of the battery's increasing charge I
don't know.

Sounds like it isn't a proper voltage regulated one then,
so you need to be careful not to overcharge the battery.

You also need to be careful about the max charging current, again
depending on battery type. Charging at 1/7th of the battery capacity
is safe with just about any type. Some batteries (e.g. car) can
safely be charged at significantly higher rates. This is the max
current though when the battery is pretty flat. As it charges, the
current will drop.

Since you haven't said exactly what type of battery or charger,
can't be more specific.

It's a car battery.

If it's been taking 3A for a few hours, it will have 9Ahrs
(less a bit for inefficiency) added to it, which is plenty
enough to start a car many times, unless there's something
wrong. The car will then charge it properly, and much faster,
whilst you do your regular driving (don't sit on the drive
reving the engine, as that's pretty pointless).

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Andrew Gabriel wrote:

It's a car battery.

If it's been taking 3A for a few hours, it will have 9Ahrs
(less a bit for inefficiency) added to it, which is plenty
enough to start a car many times, unless there's something
wrong. The car will then charge it properly, and much faster,
whilst you do your regular driving (don't sit on the drive
reving the engine, as that's pretty pointless).

It's a 60Ah battery. The terminal voltage isn't yet up to 13V.

It's a fairly new battery, yet either there is something wrong with it,
or there is something wrong with the car (that is draining it rapidly
while it sits on the driveway).

The other day it was flat, so I charged it for an hour or so, it started
up right away, then later that morning it was flat again.

Daniele

On Fri, 9 Oct 2009 15:57:07 +0100, D.M. Procida wrote:

It's a fairly new battery, yet either there is something wrong with it,
or there is something wrong with the car (that is draining it rapidly
while it sits on the driveway).

The other day it was flat, so I charged it for an hour or so, it started
up right away, then later that morning it was flat again.

Oh dear that doesn't bode well. One thing that car batteries hate is
having a deep discharge. A fairly new one should survive but one a
year or three old may not.

You need to find out if the car has a fault that is taking more than
a few 10's of mA when just parked up. You may need to measure this up
to half an hour after switching off and locking the car to allow it
to fully "go to sleep".

--
Cheers
Dave.

On Fri, 09 Oct 2009 15:57:07 +0100, D.M. Procida wrote:

Andrew Gabriel wrote:

It's a car battery.

If it's been taking 3A for a few hours, it will have 9Ahrs (less a bit
for inefficiency) added to it, which is plenty enough to start a car
many times, unless there's something wrong. The car will then charge it
properly, and much faster, whilst you do your regular driving (don't
sit on the drive reving the engine, as that's pretty pointless).

It's a 60Ah battery. The terminal voltage isn't yet up to 13V.

It's a fairly new battery, yet either there is something wrong with it,
or there is something wrong with the car (that is draining it rapidly
while it sits on the driveway).

The other day it was flat, so I charged it for an hour or so, it started
up right away, then later that morning it was flat again.

Daniele

Had a Daewoo (yes I know but ...) and it had a known feature where the
bracket holding the brake light switch got tired and bend slowly out the
way so eventually the brake lights stayed on - battery flat next morning.

Not saying it is but ...

On Oct 9, 3:57*pm, (D.M.
Procida) wrote:
Andrew Gabriel wrote:
It's a car battery.

If it's been taking 3A for a few hours, it will have 9Ahrs
(less a bit for inefficiency) added to it, which is plenty
enough to start a car many times, unless there's something
wrong. The car will then charge it properly, and much faster,
whilst you do your regular driving (don't sit on the drive
reving the engine, as that's pretty pointless).

It's a 60Ah battery. The terminal voltage isn't yet up to 13V.

It's a fairly new battery, yet either there is something wrong with it,
or there is something wrong with the car (that is draining it rapidly
while it sits on the driveway).

The other day it was flat, so I charged it for an hour or so, it started
up right away, then later that morning it was flat again.

Daniele


leave the battery on the car overnight again, but this time
disconnected. Then you'll know


NT

On Fri, 9 Oct 2009 15:57:07 +0100 someone who may be
(D.M. Procida) wrote
this:-

It's a fairly new battery, yet either there is something wrong with it,
or there is something wrong with the car (that is draining it rapidly
while it sits on the driveway).

The other day it was flat, so I charged it for an hour or so, it started
up right away, then later that morning it was flat again.

I would suspect a fault in the car wiring and track this down. More
and more things are being connected directly to the battery,
sometimes without even a fuse, so are able to gently drain the
battery. If one of these has gone wrong then it will be able to
drain the battery more rapidly than designed to do. It may take a
while to track down what it is, but things which are available even
when the ignition is not turned on are where I would start looking.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000...#pt3-pb3-l1g54

In article
,
D.M. Procida wrote:
It's a car battery.

Generally most home chargers are pretty weedy and car batteries are fairly
tolerant. All you really need to do is charge it sufficiently to start the
car and then let its charging system worry about topping it up. Overnight
is usually good enough for this.

Incidentally, Lidl have their rather fine chargers on sale again from next
Monday. They can be left on indefinitely since they switch to a
maintenance charge when the battery is 'full'. They've gone up since last
time - now 15 quid - but still very worth it. Enough output to charge most
batteries overnight.

--
*Starfishes have no brains *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
"Dave Plowman (News)" writes:
In article
,
D.M. Procida wrote:
It's a car battery.

Generally most home chargers are pretty weedy and car batteries are fairly
tolerant. All you really need to do is charge it sufficiently to start the
car and then let its charging system worry about topping it up. Overnight
is usually good enough for this.

5 minutes charge with one of those was enough to get one start,
when a family member flattened their battery with lights left on.
IIRC, they charge at just under 4A.

Incidentally, Lidl have their rather fine chargers on sale again from next
Monday. They can be left on indefinitely since they switch to a
maintenance charge when the battery is 'full'. They've gone up since last
time - now 15 quid - but still very worth it. Enough output to charge most
batteries overnight.

I bought one for £12, IIRC (Aldi or Lidl, can't recall,
a year or two back). When I went back later, they were
reduced to half price, so I bought 2 more. They are very
nice units. Elsewhere, they could be found for around £40.

What would be _really_ nice is if they had a switch setting
to automatically start charging when mains is applied. That
could be the basis for an effective automatic emergency supply.
Sadly, they don't do this.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In article ,
Andrew Gabriel wrote:
What would be _really_ nice is if they had a switch setting
to automatically start charging when mains is applied. That
could be the basis for an effective automatic emergency supply.
Sadly, they don't do this.

Yes. Wonder how easy it would be to modify?

--
*Save a tree, eat a beaver*

Dave Plowman London SW
To e-mail, change noise into sound.

In message , "Dave Plowman (News)"
writes
Incidentally, Lidl have their rather fine chargers on sale again from next
Monday. They can be left on indefinitely since they switch to a
maintenance charge when the battery is 'full'.
Just had a look at them, they look extremely similar (different colour
case and different name) to the Aldi one I bought last year?
They've gone up since last
time - now 15 quid - but still very worth it. Enough output to charge most
batteries overnight.


--
Clint Sharp

In article ,
"Dave Plowman (News)" writes:

Incidentally, Lidl have their rather fine chargers on sale again from next
Monday. They can be left on indefinitely since they switch to a
maintenance charge when the battery is 'full'. They've gone up since last
time - now 15 quid - but still very worth it. Enough output to charge most
batteries overnight.

I saw a few in Aldi at lunch time, 12.99.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In article ,
Andrew Gabriel wrote:
Incidentally, Lidl have their rather fine chargers on sale again from
next Monday. They can be left on indefinitely since they switch to a
maintenance charge when the battery is 'full'. They've gone up since
last time - now 15 quid - but still very worth it. Enough output to
charge most batteries overnight.

I saw a few in Aldi at lunch time, 12.99.

That's actually what Lidl sold them at. Must have been a mistake on their
website. Different colour from the old ones, though. Now grey.

--
*Time is what keeps everything from happening at once.

Dave Plowman London SW
To e-mail, change noise into sound.

"D.M. Procida" wrote in
message
...
The charger says it's running at about 3 amps. When can I consider the
battery properly charged?

The manual for the charger is unhelpfully vague, merely saying in poor
English that when the pointer is "in the left part of" the scale that
charging is complete.

Daniele

For a cheapie charger, the best indication is terminal voltage. When it's
more that 14V, I'd disconnect the charger. 13.5V is too low, and the
battery won't have been fully charged.

On 9 Oct, 13:40, (D.M.
Procida) wrote:
The charger says it's running at about 3 amps.

That means that the charge voltage is sufficiently higher than the
terminal voltage to push 3A into the battery

When can I consider the
battery properly charged?

Can't tell. Is the battery flat? Is the charger high?

On anything less than a submarine, 3A is a reasonable charge current
but a bad float current. So either your battery isn't charged yet,
it's dead and never going to charge, or the charger is over-
enthusiastic and is killing your battery as we speak. Without knowing
either the voltage, the design of the charger, or the specific gravity
of the battery electrolyte, it's impossible to tell.

With experience, you might learn that charge current for that charger
does indeed drop into a charged battery - but we can't know that yet.
If it normally does, then your battery is dead. If it never does, then
your battery _will_ be dead soon, once the charger has finished
killing it.

On the whole, batteries are expensive, Lidl's nice voltage-controlled
auto-charger is £13. Your call.