Does recharging batteries with a charger harm them?


H

Hank

Could I be right in thinking that using a battery charger to recharge
a run-down car battery tends to reduce the life of the battery? On
more than a couple of ocasions, car batteries I have owned have not
survived long after I have used mains plug-in chargers to recharge
them.

The reason the batteries needed charging was not due to any fault in
the battery; it was due to the cars having ben standing, undriven, for
a long time.

Thanks,

Hank
 
Ad

Advertisements

D

Dave Fawthrop

|!
|!Could I be right in thinking that using a battery charger to recharge
|!a run-down car battery tends to reduce the life of the battery?

Wrong.

|!more than a couple of ocasions, car batteries I have owned have not
|!survived long after I have used mains plug-in chargers to recharge
|!them.

|!The reason the batteries needed charging was not due to any fault in
|!the battery; it was due to the cars having ben standing, undriven, for
|!a long time.

Or the alternator is f*cked.

Or the battery is knackered, they only last a few years.
 
T

The Natural Philosopher

Hank said:
Could I be right in thinking that using a battery charger to recharge
a run-down car battery tends to reduce the life of the battery? On
more than a couple of ocasions, car batteries I have owned have not
survived long after I have used mains plug-in chargers to recharge
them.

The reason the batteries needed charging was not due to any fault in
the battery; it was due to the cars having ben standing, undriven, for
a long time.

Thanks,

Hank
Not at all. However batteries that get flat enough to need a charger are
usually knackered by that fact.

Once I get to having to charge a car battery, I am pretty much always in
need of a new one.
 
J

JohnW

Hank said:
Could I be right in thinking that using a battery charger to recharge
a run-down car battery tends to reduce the life of the battery? On
more than a couple of ocasions, car batteries I have owned have not
survived long after I have used mains plug-in chargers to recharge
them.
Not normally, but if it is a cheap charger ( = normal shop
model) that puts out too much charging current, in attempt to
get a "fast charge", it could do if left charging a fully
charged battery. What does reduce the life of batteries
quickly is letting the voltage fall too low between charges.
Hence, it is the "run down" state you are getting them to that
is the killer.

You can get multi-stage chargers that detect the charged state
of the battery and adjust the charging rate accordingly, right
down to a low-level maintenance rate that can be left running
permanently. As an example, see http://tinyurl.com/2y6dp9
 
D

Dave Plowman (News)

Could I be right in thinking that using a battery charger to recharge
a run-down car battery tends to reduce the life of the battery? On
more than a couple of ocasions, car batteries I have owned have not
survived long after I have used mains plug-in chargers to recharge
them.
Quite the reverse; lead acid batteries last best when kept reasonably
fully charged - hence their continued use in cars where this is generally
the case. Of course like any battery they shouldn't be overcharged.
The reason the batteries needed charging was not due to any fault in
the battery; it was due to the cars having ben standing, undriven, for
a long time.
That is the cause of the problem - car type lead acid don't like being let
go 'flat'. If the car is to be unused for more than a couple of weeks or
so disconnect the battery.
 
C

Clive Mitchell

Hank said:
Could I be right in thinking that using a battery charger to recharge a
run-down car battery tends to reduce the life of the battery? On more
than a couple of ocasions, car batteries I have owned have not survived
long after I have used mains plug-in chargers to recharge them.

The reason the batteries needed charging was not due to any fault in
the battery; it was due to the cars having ben standing, undriven, for
a long time.
Lead acid batteries are easy to destroy. They do not handle deep
discharge well and suffer from sulphation of the lead plates inside.
This is where an insulating layer forms on the surface of the plate
reducing it's ability to do it's job.

It follows that it's best to keep them topped up from time to time, but
slapping one on a cheap charger that just pumps current in constantly
will also result in damage, particularly if the acid/water level inside
isn't monitored and is allowed to drop below the top of the plates.

Care of batteries that are not being used for a while is a mix of
occasional top-ups and a bit of discharging too. You can get devices
that apparently condition the battery by pulsing a brief high current
load across it while it's on a charger.

It's a complex subject!
 
Ad

Advertisements

D

Dave Plowman (News)

You can get devices that apparently condition the battery by pulsing a
brief high current load across it while it's on a charger.
And the jury's out on whether this is just a gimmick.
 
H

Huge

Could I be right in thinking that using a battery charger to recharge
a run-down car battery tends to reduce the life of the battery?
No. But allowing car starter batteries to go flat usually ruins them,
especially if they are already a couple of years old.
 
D

Dave Fawthrop

|!Hank wrote:
|!> Could I be right in thinking that using a battery charger to recharge
|!> a run-down car battery tends to reduce the life of the battery? On
|!> more than a couple of ocasions, car batteries I have owned have not
|!> survived long after I have used mains plug-in chargers to recharge
|!> them.
|!>
|!> The reason the batteries needed charging was not due to any fault in
|!> the battery; it was due to the cars having ben standing, undriven, for
|!> a long time.
|!>
|!> Thanks,
|!>
|!> Hank
|!Not at all. However batteries that get flat enough to need a charger are
|!usually knackered by that fact.
|!
|!Once I get to having to charge a car battery, I am pretty much always in
|!need of a new one.

Not my experience! I left the car undriven for over a month and came back
to a discharged battery. Recharged it and a year later no more problems.
 
J

John.

Hank said:
Could I be right in thinking that using a battery charger to recharge
a run-down car battery tends to reduce the life of the battery? On
more than a couple of ocasions, car batteries I have owned have not
survived long after I have used mains plug-in chargers to recharge
them.

The reason the batteries needed charging was not due to any fault in
the battery; it was due to the cars having ben standing, undriven, for
a long time.

Thanks,

Hank
Even if it did, what else would you charge them with, a meat pie? :eek:)

John
 
C

Clive Mitchell

"Dave Plowman (News)" said:
And the jury's out on whether this is just a gimmick.
And it's out on those desulphation pills too.

And the chemical additives.

And those shit solar chargers that put out barely enough to light their
"power on" LED on a typical dull UK day.
 
Ad

Advertisements

C

Clive Mitchell

Julian said:
Buy another one, batteries are consumable items and are cheap! Next
time you lay-up a vehicle, pull one of the battery leads off (negative
is best) and trickle charge the battery periodically or invest in a
little 'wall wart' style battery charger that can be left connected
permanently.
And don't skimp on the battery size to save pennies. Fit the biggest
that will go in the battery bay.
 
D

Dave Plowman (News)

And it's out on those desulphation pills too.
And the chemical additives.
And those shit solar chargers that put out barely enough to light their
"power on" LED on a typical dull UK day.
And add those 'battery conditioners' at 40 quid when a realistic price
would be a tenner.
 
H

Harry Bloomfield

Hank wrote on 08/03/2007 :
Could I be right in thinking that using a battery charger to recharge
a run-down car battery tends to reduce the life of the battery? On
more than a couple of ocasions, car batteries I have owned have not
survived long after I have used mains plug-in chargers to recharge
them.
The reason the batteries needed charging was not due to any fault in
the battery; it was due to the cars having ben standing, undriven, for
a long time.

Hank
The discharge/charge cycle itself damages batteries, but this is normal
wear and and tear. If you use an old type battery charger which just
charges irrespective of need for charge, it is possible to overcharge
them which is seriously damaging to the battery.

Assuming none of the above, simply leaving a battery to go flat can
cause the most severe form of damage.
 
H

Hank

Not normally, but if it is a cheap charger ( = normal shop
model) that puts out too much charging current, in attempt to
get a "fast charge", it could do if left charging a fully
charged battery.
Thanks. I've never been quite clear about how long one should leave a
car battery on charge, using a cheap charger. I've generally left them
overnight, i.e., 8-12 hours. Is that about right?

My current car has been unused for the past 4 months and when I tried
to start her up today, there was just barely enough charge left in the
battery to fire the engine up. So I have put the battery on charge
(using a cheap charger).

Thanks also to the other respondees.

Hank
 
H

Huge

And add those 'battery conditioners' at 40 quid when a realistic price
would be a tenner.
OTOH the one I have has saved my GBP50/yr for new car batteries.

And I'm going to buy a second one for the (ride-on) lawnmower, whose
battery is dead as a door-nail, as we discovered yesterday.

Most electronics are like that, anyway. Ever taken an ECU to pieces? 5
quids worht of electronics in a 10 quid die-cast box, which costs 600
quid from the manufacturer.
 
Ad

Advertisements

T

tinnews

Huge said:
And I'm going to buy a second one for the (ride-on) lawnmower, whose
battery is dead as a door-nail, as we discovered yesterday.
Ride-on mowers and mini-tractors are really battery killers in my
experience, not because they work the battery hard or anything but
simply because they get left unused for long periods. As many others
have pointed out here it's leaving lead acid batteries uncharged (and
thus self-discharge) is what kills them.

I have both a ride-on mower and a mini-tractor and after losing a
couple of batteries this way I now have a Gunson's "automatic" charger
for each which is left connected most of the time, but especially over
the winter.

(That reminds me, see separate thread about connectors)
 
H

Huge

Ride-on mowers and mini-tractors are really battery killers in my
experience, not because they work the battery hard or anything but
simply because they get left unused for long periods. As many others
have pointed out here it's leaving lead acid batteries uncharged (and
thus self-discharge) is what kills them.
Sadly, this has the opposite problem. It's been on a charger on a timer
all winter, on low charge for 15 minutes a day. Sadly, this is
still excessive, and it electrolysed all the acid away. Topping it
up and leaving on charge all night has revitalised it enough to start
the mower and mow the grass (in March!), but I don't hold out much
hope for it to have a long and happy life!
 
J

JohnW

Sadly, this has the opposite problem. It's been on a charger on a timer
all winter, on low charge for 15 minutes a day. Sadly, this is
still excessive, and it electrolysed all the acid away. Topping it
up and leaving on charge all night has revitalised it enough to start
the mower and mow the grass (in March!), but I don't hold out much
hope for it to have a long and happy life!
I'm considering getting one of these myself - hoping for
feedback following my earlier posting :)

http://tinyurl.com/bz7ma

Seems to be a solution for classic cars. Interesting their
comment about "difficult to reach batteries" for your
application. They switch off the charging when the battery is
"full" but continue to monitor the voltage. If it falls too
low, it initiates a recharge cycle which is apparently better
than slow water loss due to gassing that happens with a
constant charging type.

That reminds me - you can get "recombiner caps" (Hydrocaps)
that are supposed to recombine the free hydrogen back into
water again to reduce the water loss. Which is the best
solution, I don't know - which is why I'm still thinking :)
 
Ad

Advertisements

H

Huge

I'm considering getting one of these myself - hoping for
feedback following my earlier posting :)

http://tinyurl.com/bz7ma
I have one of these;

http://www.airflow-uk.com/battery-conditioner.htm

Which is much the the same thing, on my TVR and before that my Cossie,
neither of which got much use in the winter. Although they are, as Dave
Plowman points out, rather expensive for what they are, I haven't
had to buy a new battery since I got one, whereas the Cossie/TVR was
getting 18 months tops out of a battery before the constant flattening
ruined them. (Modern cars drain a fair amount of current, even when
switched off. I tried to measure it on the Cossie, but the inrush
current blew the 2A fuse in my meter).

The other solution is to disconnect the battery, but that makes popping
out for a drive (on a day like today) a bit of a pain.
Seems to be a solution for classic cars. Interesting their
comment about "difficult to reach batteries" for your
application.
The TVR battery is very, very, very hard to get at. I charge it through
the cigarette lighter.
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Top