My car battery is oversized for the car. The battery is a bit old
but usually works fine. The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. No soothing.

Is this ok for a car battery or is it way too crude?

Eddie coughed up some electrons that declared:

My car battery is oversized for the car. The battery is a bit old
but usually works fine. The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. No soothing.

Is this ok for a car battery or is it way too crude?

Well, it always has been OK - never seen a car charger that was anything but
a transformer and some rectifiers - but then I haven't actually bought a
new one for 20 years!

The only concern is for the electronics in the car, but generally the
battery itself will do the smoothing, which only leaves over-voltage to be
a problem, so don't over charge the battery, which would be bad for the
battery anyway.

If you're paranoid you could disconnect the +ve and charge the battery in
isolation.

Cheers

Tim

Eddie wrote:
My car battery is oversized for the car. The battery is a bit old
but usually works fine. The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. No soothing.

Is this ok for a car battery or is it way too crude?

Both; it is crude but it's ok for a car battery.

--
-----------------------------------------------------------------------
To reply to me directly:

Replace privacy.net with: totalise DOT co DOT uk and replace me with
gareth.harris

Tim S wrote:
Eddie coughed up some electrons that declared:

My car battery is oversized for the car. The battery is a bit old
but usually works fine. The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. No soothing.

Is this ok for a car battery or is it way too crude?

Well, it always has been OK - never seen a car charger that was anything but
a transformer and some rectifiers - but then I haven't actually bought a
new one for 20 years!

The only concern is for the electronics in the car, but generally the
battery itself will do the smoothing, which only leaves over-voltage to be
a problem, so don't over charge the battery, which would be bad for the
battery anyway.

If you're paranoid you could disconnect the +ve and charge the battery in
isolation.


Automotive electronics is (or should be) designed to withstand all sorts
of horrible things. For example, transients of a few hundred volts from
the ignition coil or being jump started from a 24V battery. For details
see:

http://www.st.com/stonline/products/...re/an/3583.pdf


--
-----------------------------------------------------------------------
To reply to me directly:

Replace privacy.net with: totalise DOT co DOT uk and replace me with
gareth.harris

Tim S wrote:
Eddie coughed up some electrons that declared:

My car battery is oversized for the car. The battery is a bit old
but usually works fine. The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. No soothing.

Is this ok for a car battery or is it way too crude?

Well, it always has been OK - never seen a car charger that was
anything but a transformer and some rectifiers - but then I haven't
actually bought a new one for 20 years!

The only concern is for the electronics in the car, but generally the
battery itself will do the smoothing, which only leaves over-voltage
to be a problem, so don't over charge the battery, which would be bad
for the battery anyway.

If you're paranoid you could disconnect the +ve and charge the
battery in isolation.

Which is likely to bugger up the radio code! Do you know what yours is? I'm
trying to find a roundtuit to pull the radio out to find necessary info and
go to the main dealers as a result of a similar episode!

On Sun, 07 Jun 2009 20:13:54 +0100, Gareth wrote:

Eddie wrote:
My car battery is oversized for the car. The battery is a bit old
but usually works fine. The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. No soothing.

Is this ok for a car battery or is it way too crude?

Both; it is crude but it's ok for a car battery.

Modern "intelligent" chargers are much kinder to the battery and usually
have an automatic maintain mode, so you don't have to remove the charger as
soon as it's charged and can even use them to maintain the charge if the
vehicle is not used for some time. Old fashioned basic chargers will
sometimes recover batteries that an intelligent charger won't charge
though, but if you leave them on too long they'll boil the electrolyte off.
Personally, I use an intelligent charger, but have an old charger to start
the charge on any very flat battery, which I can then complete with the
modern one.

SteveW

"Eddie" wrote in message
...
My car battery is oversized for the car. The battery is a bit old
but usually works fine. The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. No soothing.

Is this ok for a car battery or is it way too crude?

Check the electrolyte level in your battery.Filtered DC causes polarization
of the battery.

Bob

On Sun, 07 Jun 2009 20:50:26 +0100, wrote:


"Eddie" wrote in message
...
My car battery is oversized for the car. The battery is a bit old
but usually works fine. The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. No soothing.

Is this ok for a car battery or is it way too crude?

Check the electrolyte level in your battery.Filtered DC causes
polarization
of the battery.

Bob



An unpolarised battery isn't much use.

On 7 Jun 2009 20:50, wrote:


"Eddie" wrote in message
...
My car battery is oversized for the car. The battery is a
bit old but usually works fine. The battery is flat (I left
the lights on).

My fancy new modern charger senses a poor battery and only
puts in very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was
only a transformer and a big rectifier. That's it. No
soothing.

Is this ok for a car battery or is it way too crude?

Check the electrolyte level in your battery.Filtered DC causes
polarization of the battery.

Bob


It's a sealed battery. Are they better or worse than electrolyte
batteries when the charge drops to very low?

On Sun, 07 Jun 2009 21:31:56 +0100, Eddie wrote:

On 7 Jun 2009 20:50, wrote:


"Eddie" wrote in message
...
My car battery is oversized for the car. The battery is a
bit old but usually works fine. The battery is flat (I left
the lights on).

My fancy new modern charger senses a poor battery and only
puts in very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was
only a transformer and a big rectifier. That's it. No
soothing.

Is this ok for a car battery or is it way too crude?

Check the electrolyte level in your battery.Filtered DC causes
polarization of the battery.

Bob


It's a sealed battery. Are they better or worse than electrolyte
batteries when the charge drops to very low?

Similar, the difference is when they're overcharged , but any battery with
a high CCA compared to it's capacity won't like being hard discharged.
Boost it for a few hours on the old charger, charge it up on a decent one
or by driving the car & see if it's still happy.

In message op.uu57yx1mhaghkf@lucy, Duncan Wood
writes
On Sun, 07 Jun 2009 20:50:26 +0100, wrote:


"Eddie" wrote in message
...
My car battery is oversized for the car. The battery is a bit old
but usually works fine. The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. No soothing.

Is this ok for a car battery or is it way too crude?

Check the electrolyte level in your battery.Filtered DC causes
polarization
of the battery.

Bob



An unpolarised battery isn't much use.

Dunno - might make a good door stop

--
geoff

On Sun, 07 Jun 2009 22:02:04 +0100, geoff wrote:

In message op.uu57yx1mhaghkf@lucy, Duncan Wood
writes
On Sun, 07 Jun 2009 20:50:26 +0100, wrote:


"Eddie" wrote in message
...
My car battery is oversized for the car. The battery is a bit old
but usually works fine. The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. No soothing.

Is this ok for a car battery or is it way too crude?

Check the electrolyte level in your battery.Filtered DC causes
polarization
of the battery.

Bob



An unpolarised battery isn't much use.

Dunno - might make a good door stop


Fair point.

In message , geoff
writes
An unpolarised battery isn't much use.

Dunno - might make a good door stop



Depends a bit on size.

Last week a VERY large hornet decided to take a stroll across my work
bench. A 2.8Ah Yuasa flattened it perfectly. Although I must admit
that it was not unpolarised, the battery that is.

Any one have any other uses for old batteries?


--
Bill

Tim S wrote:

Eddie coughed up some electrons that declared:

My car battery is oversized for the car. The battery is a bit old
but usually works fine. The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. No soothing.

Is this ok for a car battery or is it way too crude?

Well, it always has been OK - never seen a car charger that was
anything but a transformer and some rectifiers - but then I haven't
actually bought a new one for 20 years!

The only concern is for the electronics in the car, but generally the
battery itself will do the smoothing, which only leaves over-voltage
to be a problem, so don't over charge the battery, which would be bad
for the battery anyway.

If you're paranoid you could disconnect the +ve and charge the battery
in isolation.

Cheers

Tim

If you disconnect the battery, make sure you have the key code for the
radio !

--
Best Regards:
Baron.

On 7 June, 21:17, "Duncan Wood" wrote:
On Sun, 07 Jun 2009 20:50:26 +0100, wrote:

"Eddie" wrote in message
m...
My car battery is oversized for the car. *The battery is a bit old
but usually works fine. *The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. *I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. *No soothing.

Is this ok for a car battery or is it way too crude?

Check the electrolyte level in your battery.Filtered DC causes *
polarization
of the battery.

Bob

An unpolarised battery isn't much use.

An AC battery would be darn handy...

Adam

On Sun, 07 Jun 2009 22:38:33 +0100, Adam Aglionby
wrote:

On 7 June, 21:17, "Duncan Wood" wrote:
On Sun, 07 Jun 2009 20:50:26 +0100, wrote:

"Eddie" wrote in message
m...
My car battery is oversized for the car. *The battery is a bit old
but usually works fine. *The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. *I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. *No soothing.

Is this ok for a car battery or is it way too crude?

Check the electrolyte level in your battery.Filtered DC causes *
polarization
of the battery.

Bob

An unpolarised battery isn't much use.

An AC battery would be darn handy...

Adam

You've not met Radioheads big battery have you :-)

On Sun, 07 Jun 2009 19:34:39 +0100, Tim S wrote:

Eddie coughed up some electrons that declared:

My car battery is oversized for the car. The battery is a bit old
but usually works fine. The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. No soothing.

Is this ok for a car battery or is it way too crude?

Well, it always has been OK - never seen a car charger that was anything but
a transformer and some rectifiers - but then I haven't actually bought a
new one for 20 years!

The only concern is for the electronics in the car, but generally the
battery itself will do the smoothing, which only leaves over-voltage to be
a problem, so don't over charge the battery, which would be bad for the
battery anyway.

If you're paranoid you could disconnect the +ve and charge the battery in
isolation.

Cheers

Tim


Car batteries are not fussy about the charger waveform. In fact a
half-wave rectifier will do the job very well.

DJ

In article ,
Eddie wrote:
My car battery is oversized for the car. The battery is a bit old
but usually works fine. The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. No soothing.

Is this ok for a car battery or is it way too crude?

An ancient crude charger is actually quite good at recovering a flat and
possibly sulphated battery - it will output quite a high voltage with a
high impedance load, which is needed to help combat the sulphation.
However, after the battery has started to take a reasonable charge rate,
ditch it and use your modern one.

--
*Would a fly without wings be called a walk?

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

On Sun, 07 Jun 2009 18:19:51 GMT, Eddie wrote:

My car battery is oversized for the car. The battery is a bit old
but usually works fine. The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. No soothing.

Is this ok for a car battery or is it way too crude?


Electrons are electrons to the battery. If they are at high enough
potential to cause a charge condition on the battery, they will.

Eddie wrote:

My car battery is oversized for the car. The battery is a bit old
but usually works fine. The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. No soothing.

Is this ok for a car battery or is it way too crude?
Actually, that is *better*; the pulses tend to de-sulphate the battery.

Eddie wrote:

On 7 Jun 2009 20:50, wrote:


"Eddie" wrote in message
om...

My car battery is oversized for the car. The battery is a
bit old but usually works fine. The battery is flat (I left
the lights on).

My fancy new modern charger senses a poor battery and only
puts in very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was
only a transformer and a big rectifier. That's it. No
soothing.

Is this ok for a car battery or is it way too crude?

Check the electrolyte level in your battery.Filtered DC causes
polarization of the battery.

Bob



It's a sealed battery. Are they better or worse than electrolyte
batteries when the charge drops to very low?
Sealed batteries use a gelled electolyte, and so the charge rate must
be limited to prevent outgassing.
Within that limit, they are supposed to tolerate extended charging
times because the internal chemistry changes some to compensate.

StickThatInYourPipeAndSmokeIt wrote:

On Sun, 07 Jun 2009 18:19:51 GMT, Eddie wrote:


My car battery is oversized for the car. The battery is a bit old
but usually works fine. The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. No soothing.

Is this ok for a car battery or is it way too crude?



Electrons are electrons to the battery. If they are at high enough
potential to cause a charge condition on the battery, they will.
Well!!!
My electrons are smaller than your electrons; take THAT!!

In article ,
"Clot" writes:

Which is likely to bugger up the radio code! Do you know what yours is? I'm
trying to find a roundtuit to pull the radio out to find necessary info and
go to the main dealers as a result of a similar episode!

If it's the original radio, you just need the registration number.

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

In article ,
Robert Baer wrote:
It's a sealed battery. Are they better or worse than electrolyte
batteries when the charge drops to very low?
Sealed batteries use a gelled electolyte, and so the charge rate must
be limited to prevent outgassing.

Although they're called sealed, car batteries are actually low maintenance
types which are still wet. Some serious off roaders may use SLA - but
don't know of any car which does.

Within that limit, they are supposed to tolerate extended charging
times because the internal chemistry changes some to compensate.

--
*Never test the depth of the water with both feet.*

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

"Dave Plowman (News)" wrote in message
...
In article ,
Eddie wrote:
My car battery is oversized for the car. The battery is a bit old
but usually works fine. The battery is flat (I left the lights
on).

My fancy new modern charger senses a poor battery and only puts in
very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was only a
transformer and a big rectifier. That's it. No soothing.

Is this ok for a car battery or is it way too crude?

An ancient crude charger is actually quite good at recovering a flat and
possibly sulphated battery - it will output quite a high voltage with a
high impedance load, which is needed to help combat the sulphation.
However, after the battery has started to take a reasonable charge rate,
ditch it and use your modern one.

I keep one just for that purpose & then connect the new fangled smart
charger soon as the batt can take it. From experience though, if connecting
a totally flat batt get ready to switch off the old charger before the
needle goes off the scale followed by a big bang as the bridge rectifier
decides its had enough!!

In article ,
Redwood wrote:
I keep one just for that purpose & then connect the new fangled smart
charger soon as the batt can take it. From experience though, if
connecting a totally flat batt get ready to switch off the old charger
before the needle goes off the scale followed by a big bang as the
bridge rectifier decides its had enough!!

My ancient one has a series resistor to limit the current - and has both
mains and DC fuses.

--
*Letting a cat out of the bag is easier than putting it back in *

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

"Dave Plowman (News)" wrote:

In article ,
Redwood wrote:
I keep one just for that purpose & then connect the new fangled smart
charger soon as the batt can take it. From experience though, if
connecting a totally flat batt get ready to switch off the old charger
before the needle goes off the scale followed by a big bang as the
bridge rectifier decides its had enough!!

My ancient one has a series resistor to limit the current - and has both
mains and DC fuses.


The one I built in the '60s has a Variac to set the charging current,
ot float voltage.


--
You can't have a sense of humor, if you have no sense!

On Mon, 08 Jun 2009 09:27:50 +0100, Dave Plowman (News)
wrote:

In article ,
Robert Baer wrote:
It's a sealed battery. Are they better or worse than electrolyte
batteries when the charge drops to very low?
Sealed batteries use a gelled electolyte, and so the charge rate must
be limited to prevent outgassing.

Although they're called sealed, car batteries are actually low
maintenance
types which are still wet. Some serious off roaders may use SLA - but
don't know of any car which does.



MX5s IIRC

Andrew Gabriel wrote:
In article ,
"Clot" writes:

Which is likely to bugger up the radio code! Do you know what yours
is? I'm trying to find a roundtuit to pull the radio out to find
necessary info and go to the main dealers as a result of a similar
episode!

If it's the original radio, you just need the registration number.

It is and thanks.

On Sun, 7 Jun 2009 22:32:11 +0100, Bill
wrote:

In message , geoff
writes
An unpolarised battery isn't much use.

Dunno - might make a good door stop



Depends a bit on size.

Last week a VERY large hornet decided to take a stroll across my work
bench. A 2.8Ah Yuasa flattened it perfectly. Although I must admit
that it was not unpolarised, the battery that is.

Any one have any other uses for old batteries?

Yes, when religion peddlers come to the door, they make great things
to throw.

"But, I didn't see that guy standing there, sorry!" bg

BTW, don't unpolarized batteries just provide AC? And if that's the
case, how do you specifiy 50 or 60 Hz?

On Jun 8, 7:38*am, PeterD wrote:
On Sun, 7 Jun 2009 22:32:11 +0100, Bill
wrote:

In message , geoff
writes
An unpolarised battery isn't much use.

Dunno - might make a good door stop

Depends a bit on size.

Last week a VERY large hornet decided to take a stroll across my work
bench. *A 2.8Ah Yuasa flattened it perfectly. *Although I must admit
that it was not unpolarised, the battery that is.

Any one have any other uses for old batteries?

Yes, when religion peddlers come to the door, they make great things
to throw.

"But, I didn't see that guy standing there, sorry!" bg

BTW, don't unpolarized batteries just provide AC?

Yes. 0VAC

And if that's the case, how do you specifiy 50 or 60 Hz?

0VAC 50/60Hz.


Of course, in Spice they can deliver whatever voltage/frequency you
want. No need to worry about the little details of thermodynamics
either.

PeterD wrote:

On Sun, 7 Jun 2009 22:32:11 +0100, Bill
wrote:


In message , geoff
writes

An unpolarised battery isn't much use.

Dunno - might make a good door stop



Depends a bit on size.

Last week a VERY large hornet decided to take a stroll across my work
bench. A 2.8Ah Yuasa flattened it perfectly. Although I must admit
that it was not unpolarised, the battery that is.

Any one have any other uses for old batteries?


Yes, when religion peddlers come to the door, they make great things
to throw.

"But, I didn't see that guy standing there, sorry!" bg

BTW, don't unpolarized batteries just provide AC? And if that's the
case, how do you specifiy 50 or 60 Hz?
....that is how fast it tumbles when thrown?

On 7 Jun 2009 19:34, Tim S wrote:

Eddie coughed up some electrons that declared:

My car battery is oversized for the car. The battery is a
bit old but usually works fine. The battery is flat (I left
the lights on).

My fancy new modern charger senses a poor battery and only
puts in very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was
only a transformer and a big rectifier. That's it. No
soothing.

Is this ok for a car battery or is it way too crude?

Well, it always has been OK - never seen a car charger that
was anything but a transformer and some rectifiers - but then
I haven't actually bought a new one for 20 years!


I'm the OP. I think mine is over 30 years old.

I took the casing off (rivetted of course) to see the inside:

front
http://i44.tinypic.com/wuq7p5.jpg

transformer
http://i44.tinypic.com/2dmfsef.jpg

rectifier
http://i40.tinypic.com/2i0dnyp.jpg


It sure looks old!

Eddie

The only concern is for the electronics in the car, but
generally the battery itself will do the smoothing, which only
leaves over-voltage to be a problem, so don't over charge the
battery, which would be bad for the battery anyway.

If you're paranoid you could disconnect the +ve and charge the
battery in isolation.

Cheers
Tim

On 8 Jun 2009 09:32, Redwood wrote:

"Dave Plowman (News)" wrote:
Eddie wrote:


My car battery is oversized for the car. The battery is a
bit old but usually works fine. The battery is flat (I left
the lights on).

My fancy new modern charger senses a poor battery and only
puts in very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was
only a transformer and a big rectifier. That's it. No
soothing.

Is this ok for a car battery or is it way too crude?

An ancient crude charger is actually quite good at recovering
a flat and possibly sulphated battery - it will output quite
a high voltage with a high impedance load, which is needed to
help combat the sulphation. However, after the battery has
started to take a reasonable charge rate, ditch it and use
your modern one.

I keep one just for that purpose & then connect the new
fangled smart charger soon as the batt can take it. From
experience though, if connecting a totally flat batt get ready
to switch off the old charger before the needle goes off the
scale followed by a big bang as the bridge rectifier decides
its had enough!!


I'm the OP. Oddly enough when I used my old charger on the almost
flat low maintenance battery, the ammeter needle hardly moved at
all.

After a few minutes the needle was about midway on the scale where
it more or less stayed for a few hours.

What was happening? Didn't see any great rush of current as you
might have once had!

PHOTOS:
front = http://i44.tinypic.com/wuq7p5.jpg
transformer = http://i44.tinypic.com/2dmfsef.jpg
rectifier = http://i40.tinypic.com/2i0dnyp.jpg

On 8 Jun 2009 00:09, StickThatInYourPipeAndSmokeIt wrote:

On Sun, 07 Jun 2009 18:19:51 GMT, Eddie wrote:

My car battery is oversized for the car. The battery is a
bit old but usually works fine. The battery is flat (I left
the lights on).

My fancy new modern charger senses a poor battery and only
puts in very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was
only a transformer and a big rectifier. That's it. No
soothing.

Is this ok for a car battery or is it way too crude?


Electrons are electrons to the battery. If they are at high
enough potential to cause a charge condition on the battery,
they will.


I was kind of worrying that unsmoothed AC might not be too good for
the battery.

On 7 Jun 2009 19:34, Tim S wrote:

Eddie coughed up some electrons that declared:

My car battery is oversized for the car. The battery is a
bit old but usually works fine. The battery is flat (I left
the lights on).

My fancy new modern charger senses a poor battery and only
puts in very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was
only a transformer and a big rectifier. That's it. No
soothing.

Is this ok for a car battery or is it way too crude?

Well, it always has been OK - never seen a car charger that
was anything but a transformer and some rectifiers - but then
I haven't actually bought a new one for 20 years!


I'm the OP. I think my battery charger is over 30 years old!

I took the casing off (rivetted of course) to see the inside:

front = http://i44.tinypic.com/wuq7p5.jpg
transformer = http://i44.tinypic.com/2dmfsef.jpg
rectifier = http://i40.tinypic.com/2i0dnyp.jpg

It sure looks dated!

Eddie

The only concern is for the electronics in the car, but
generally the battery itself will do the smoothing, which only
leaves over-voltage to be a problem, so don't over charge the
battery, which would be bad for the battery anyway.

If you're paranoid you could disconnect the +ve and charge the
battery in isolation.

Cheers
Tim

On Mon, 08 Jun 2009 21:30:32 +0100, Eddie wrote:

On 8 Jun 2009 00:09, StickThatInYourPipeAndSmokeIt wrote:

On Sun, 07 Jun 2009 18:19:51 GMT, Eddie wrote:

My car battery is oversized for the car. The battery is a
bit old but usually works fine. The battery is flat (I left
the lights on).

My fancy new modern charger senses a poor battery and only
puts in very little charge.

I used to use a really old charger to charge this battery
successfully. I opened up the old charger and saw it was
only a transformer and a big rectifier. That's it. No
soothing.

Is this ok for a car battery or is it way too crude?


Electrons are electrons to the battery. If they are at high
enough potential to cause a charge condition on the battery,
they will.


I was kind of worrying that unsmoothed AC might not be too good for
the battery.


That's what the diodes are for, it never actually alternates.

In message , PeterD
writes
On Sun, 7 Jun 2009 22:32:11 +0100, Bill
wrote:

In message , geoff
writes
An unpolarised battery isn't much use.

Dunno - might make a good door stop



Depends a bit on size.

Last week a VERY large hornet decided to take a stroll across my work
bench. A 2.8Ah Yuasa flattened it perfectly. Although I must admit
that it was not unpolarised, the battery that is.

Any one have any other uses for old batteries?

Yes, when religion peddlers come to the door, they make great things
to throw.

"But, I didn't see that guy standing there, sorry!" bg

BTW, don't unpolarized batteries just provide AC? And if that's the
case, how do you specifiy 50 or 60 Hz?


The further you drop it, the more it hurts ...

--
geoff

On Mon, 08 Jun 2009 20:34:13 GMT, Eddie wrote:


It sure looks dated!

That's fine. It is fitted with an olfactory failure detector so if it
goes wrong in the dark you will know all about it.

In article ,
Eddie wrote:

I'm the OP. Oddly enough when I used my old charger on the almost
flat low maintenance battery, the ammeter needle hardly moved at
all.

After a few minutes the needle was about midway on the scale where
it more or less stayed for a few hours.

What was happening? Didn't see any great rush of current as you
might have once had!

That sounds like a classic symptom of the battery being badly sulphated.

Lead-acid batteries run on... well, lead and (sulphuric) acid. The
electrochemical reaction which produces current, is one in which the
lead reacts with the acid. converting the lead to lead sulphate. When
you re-charge the battery, the reaction is reversed... the lead
sulphate is broken up into lead (metallic) and sulphate ion, which
goes back into the electrolyte to once again form sulphuric acid.

The lead sulphate which is formed during discharge has a couple of
different crystal forms. The initial deposition of sulphate isn't too
difficult to dissolve... but it converts spontaneously to a different
crystal form which is hard, difficult to dissolve, and forms an
effective insulator.

I think that's what happened to your battery. When you initially
tried to recharge it, the plates were covered with a uniform layer of
lead sulphate, and were thus well insulated from one another. Very
little current could flow. After a few minutes, the relatively high
voltage from the old-style charger managed to break down some of the
sulphate layer, allowing an increase in the current flow.

There are techniques and devices on the market which are intended to
reverse the sulphation of batteries. They usually involve some form
of high-voltage pulse charging, sometimes using an inductive "tank"
circuit to create very short radio-frequency pulses. This is supposed
to break down the insoluble sulphate crystals. Some people swear by
these devices, other people swear that they're useless.

Deep-discharging most car batteries (low-maintenance or otherwise) is
usually said to be very bad for them. The extensive conversion of
lead to lead sulphate (and then back again) damages the structure of
the lead plates, and the plates begin to crumble and disintegrate,
greatly shortening the battery's lifetime.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!