What's the consensus of opinion on whether it's OK to leave a car battery
on continuous (float) charge? Wikipedia says 'batteries kept on
continuous float charge will have corrosion in the electrodes and result
in premature failure' but other sites seem to recommend the practice when
the vehicle is in infrequent use.

Richard.
http://www.rtrussell.co.uk/

On Feb 6, 2:25*pm, "Richard Russell" wrote:
What's the consensus of opinion on whether it's OK to leave a car battery *
on continuous (float) charge?

Float is fine, but check that the voltage is spot-on for floating that
exact battery technology and also that the float voltage is
temperature compensated. Most "float" chargers sold are just normal
chargers with a ballast resistor to limit current. Fine for leaving on
accidentally for a few days, but they aren't a real float charger.

Generally for single car batteries that are stored in a shed nearby,
protect from frost, charge them on a decent auto charge once a month
and ignore them otherwise.

In message
,
Andy Dingley writes
On Feb 6, 2:25*pm, "Richard Russell" wrote:
What's the consensus of opinion on whether it's OK to leave a car battery *
on continuous (float) charge?

Float is fine, but check that the voltage is spot-on for floating that
exact battery technology and also that the float voltage is
temperature compensated. Most "float" chargers sold are just normal
chargers with a ballast resistor to limit current. Fine for leaving on
accidentally for a few days, but they aren't a real float charger.

Generally for single car batteries that are stored in a shed nearby,
protect from frost, charge them on a decent auto charge once a month
and ignore them otherwise.

On the subject of batteries, whats the best way of rejuvinating a
sulphated dead battery, whack it with rectified mains with a bulb for a
load ?


--
geoff

"geoff" wrote in message
...
In message
, Andy
Dingley writes
On Feb 6, 2:25 pm, "Richard Russell" wrote:
What's the consensus of opinion on whether it's OK to leave a car
battery on continuous (float) charge?

Float is fine, but check that the voltage is spot-on for floating that
exact battery technology and also that the float voltage is
temperature compensated. Most "float" chargers sold are just normal
chargers with a ballast resistor to limit current. Fine for leaving on
accidentally for a few days, but they aren't a real float charger.

Generally for single car batteries that are stored in a shed nearby,
protect from frost, charge them on a decent auto charge once a month
and ignore them otherwise.

On the subject of batteries, whats the best way of rejuvinating a
sulphated dead battery, whack it with rectified mains with a bulb for a
load ?

We used to do similar to that for blowing crap off crt guns.

brass monkey wrote:
"geoff" wrote in message
...
On the subject of batteries, whats the best way of rejuvinating a
sulphated dead battery, whack it with rectified mains with a bulb for a
load ?

We used to do similar to that for blowing crap off crt guns.


Fully charge it at the ten hour rate, take it off charge for a couple of
days and repeat. Sometimes helps, but not a lot.

You used to be able to buy pills to drop into the electrolyte (EDTA =
ethalene diamine tetra acetic acid), which helped a bit.

If they were *really* bad and refused to take a charge any other way, we
used to whack 'em across a heavy duty 24V start/ charge unit on flat out
for a minute or two, (About 100 amps...) then charge as normal. That
often got another week or two of use out of them. It was kill or cure,
though.

Otherwise, flog 'em for scrap and buy new ones, which often have more
capacity in a smaller case, anyway.

There's an American unit by Pulse tech, which claims to do the job.

--
Tciao for Now!

John.

Richard Russell laid this down on his screen :
What's the consensus of opinion on whether it's OK to leave a car battery on
continuous (float) charge? Wikipedia says 'batteries kept on continuous
float charge will have corrosion in the electrodes and result in premature
failure' but other sites seem to recommend the practice when the vehicle is
in infrequent use.

I have three batteries kept almost permanently on a float charge and I
have done this for many years without any problems. Just make sure the
float charger outputs an accurate float voltage.

I bought a couple of the Lidl chargers on sale a few weeks ago -
judging by the tests I carried out, these charge fully, then fall back
to an perfectly accurate float charge voltage.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

On Sun, 06 Feb 2011 16:44:46 -0000, Harry Bloomfield
wrote:

I bought a couple of the Lidl chargers on sale a few weeks ago - judging
by the tests I carried out, these charge fully, then fall back to an
perfectly accurate float charge voltage.

I missed the Lidl offer. Any idea whether these are any good:

http://www.amazon.co.uk/Black-Decker...7010523&sr=8-3

I can well believe that temperature compensation is vital, but of course
that isn't mentioned.

Richard (G4BAU).
http://www.rtrussell.co.uk/

On Sun, 06 Feb 2011 16:06:49 +0000, John Williamson wrote:
brass monkey wrote:
"geoff" wrote in message
...
On the subject of batteries, whats the best way of rejuvinating a
sulphated dead battery, whack it with rectified mains with a bulb for a
load ?

We used to do similar to that for blowing crap off crt guns.


Fully charge it at the ten hour rate, take it off charge for a couple of
days and repeat. Sometimes helps, but not a lot.

You used to be able to buy pills to drop into the electrolyte (EDTA =
ethalene diamine tetra acetic acid), which helped a bit.

If they were *really* bad and refused to take a charge any other way, we
used to whack 'em across a heavy duty 24V start/ charge unit on flat out
for a minute or two, (About 100 amps...) then charge as normal. That
often got another week or two of use out of them. It was kill or cure,
though.

Otherwise, flog 'em for scrap and buy new ones, which often have more
capacity in a smaller case, anyway.

There's an American unit by Pulse tech, which claims to do the job.

If you fancy your hand at a bit of electronics, there are plenty of
desulfator [sic] circuits around. Essentially they work by sending
short, high voltage pulses into the battery. The theory is that the
high voltage does some magic (technical term) to the plates which
removes some/all of the insultaing material that builds up and prevents
them from retaining a charge. I haven't tried one, myself but I'd be
interested in knowing if this is just hokum or if there's some truth
in the claims.



--
http://thisreallyismyhost.99k.org/06...5011010385.php

geoff used his keyboard to write :
In message
, Andy
Dingley writes
On Feb 6, 2:25*pm, "Richard Russell" wrote:
What's the consensus of opinion on whether it's OK to leave a car battery
*
on continuous (float) charge?

Float is fine, but check that the voltage is spot-on for floating that
exact battery technology and also that the float voltage is
temperature compensated. Most "float" chargers sold are just normal
chargers with a ballast resistor to limit current. Fine for leaving on
accidentally for a few days, but they aren't a real float charger.

Generally for single car batteries that are stored in a shed nearby,
protect from frost, charge them on a decent auto charge once a month
and ignore them otherwise.

On the subject of batteries, whats the best way of rejuvinating a sulphated
dead battery, whack it with rectified mains with a bulb for a load ?

Pulse charging - a series of pulses of high current is supposed to help
shift the sulphate.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

on 06/02/2011, Richard Russell supposed :
On Sun, 06 Feb 2011 16:44:46 -0000, Harry Bloomfield
wrote:

I bought a couple of the Lidl chargers on sale a few weeks ago - judging by
the tests I carried out, these charge fully, then fall back to an perfectly
accurate float charge voltage.

I missed the Lidl offer. Any idea whether these are any good:

http://www.amazon.co.uk/Black-Decker...7010523&sr=8-3

I can well believe that temperature compensation is vital, but of course that
isn't mentioned.

I would suggest waiting for one of the Aldi/Lidl ones to come back on
offer - much better spec., water resistant and you could almost buy
three for the B&D price.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

In message , John Williamson
writes
brass monkey wrote:
"geoff" wrote in message
...
On the subject of batteries, whats the best way of rejuvinating a
sulphated dead battery, whack it with rectified mains with a bulb for
a load ?
We used to do similar to that for blowing crap off crt guns.

Fully charge it at the ten hour rate, take it off charge for a couple
of days and repeat. Sometimes helps, but not a lot.

You used to be able to buy pills to drop into the electrolyte (EDTA =
ethalene diamine tetra acetic acid), which helped a bit.

If they were *really* bad and refused to take a charge any other way,
we used to whack 'em across a heavy duty 24V start/ charge unit on flat
out for a minute or two, (About 100 amps...) then charge as normal.
That often got another week or two of use out of them. It was kill or
cure, though.

The only source I have of 100A is another battery


Otherwise, flog 'em for scrap and buy new ones, which often have more
capacity in a smaller case, anyway.

Just want to put an old battery on an old car to flog it


There's an American unit by Pulse tech, which claims to do the job.


Yeah - seems to do what I typed above

which is why I typed it

bit of flex and a 10A bridge rectifier it is, then


--
geoff

"geoff" wrote in message
...
In message , John Williamson
writes
brass monkey wrote:
"geoff" wrote in message
...
On the subject of batteries, whats the best way of rejuvinating
a
sulphated dead battery, whack it with rectified mains with a bulb
for
a load ?
We used to do similar to that for blowing crap off crt guns.

Fully charge it at the ten hour rate, take it off charge for a
couple
of days and repeat. Sometimes helps, but not a lot.

You used to be able to buy pills to drop into the electrolyte (EDTA
=
ethalene diamine tetra acetic acid), which helped a bit.

If they were *really* bad and refused to take a charge any other
way,
we used to whack 'em across a heavy duty 24V start/ charge unit on
flat
out for a minute or two, (About 100 amps...) then charge as normal.
That often got another week or two of use out of them. It was kill
or
cure, though.

The only source I have of 100A is another battery


Otherwise, flog 'em for scrap and buy new ones, which often have
more
capacity in a smaller case, anyway.

Just want to put an old battery on an old car to flog it


There's an American unit by Pulse tech, which claims to do the job.


Yeah - seems to do what I typed above

which is why I typed it

bit of flex and a 10A bridge rectifier it is, then


--
geoff

I bought one of the pulser units a couple of years ago to revive the
deep cycle batteries in an electric 'factory truck'. I was rather
skeptical as the truck had been idle/unused for a year. :Left it on
for a few days then did a discharge test (roll of fence wire wrapped
round an asbestos flue pipe as a load) Amazngly 90% of full capacity
on a 10 hour rate test..

AWEM

In article ,
John Williamson wrote:
If they were *really* bad and refused to take a charge any other way, we
used to whack 'em across a heavy duty 24V start/ charge unit on flat out
for a minute or two, (About 100 amps...) then charge as normal. That
often got another week or two of use out of them. It was kill or cure,
though.

A sulphated battery will have such a high internal resistance, you'll not
'whack' high current into it with any charger. What you do need is fairly
high voltage - 30 or so - to speed up the chemical process. An old basic
charger with no regulation is likely to achieve this rather than a modern
one, unless the modern one is designed to pulse charge.

--
*Why is it that doctors call what they do "practice"?

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

On Sun, 06 Feb 2011 18:14:04 GMT, Harry Bloomfield wrote:

I would suggest waiting for one of the Aldi/Lidl ones to come back on
offer - much better spec., water resistant and you could almost buy
three for the B&D price.

Or check out the one that CostCo and possibly Makro have that is very
similar.

--
Cheers
Dave.

Dave Plowman (News) wrote:
In article ,
John Williamson wrote:
If they were *really* bad and refused to take a charge any other way, we
used to whack 'em across a heavy duty 24V start/ charge unit on flat out
for a minute or two, (About 100 amps...) then charge as normal. That
often got another week or two of use out of them. It was kill or cure,
though.

A sulphated battery will have such a high internal resistance, you'll not
'whack' high current into it with any charger. What you do need is fairly
high voltage - 30 or so - to speed up the chemical process. An old basic
charger with no regulation is likely to achieve this rather than a modern
one, unless the modern one is designed to pulse charge.

Well, our 24V jump start/ rapid charge unit was high enough voltage to
give us an indicated 60 rising to 100 amps going into a 12 volt battery.
Maximum one or two minutes, before the electrloyte started either
boiling or gassing. As I said, kill or cure, but we were doing it for a
fleet of rather tired old coaches, which *had* to be out on the road
*now*. This charger would start a vehicle with completely flat batteries
within seconds of being connected, too.

The 22 to 24 volt bit is what the modern pulse power units do, except
they don't ouptut that much current, and they're controlled by a
microprocessor and not a fitter reading a meter. They also take rather
longer to do the job.

--
Tciao for Now!

John.

In article ,
John Williamson wrote:
A sulphated battery will have such a high internal resistance, you'll
not 'whack' high current into it with any charger. What you do need is
fairly high voltage - 30 or so - to speed up the chemical process. An
old basic charger with no regulation is likely to achieve this rather
than a modern one, unless the modern one is designed to pulse charge.

Well, our 24V jump start/ rapid charge unit was high enough voltage to
give us an indicated 60 rising to 100 amps going into a 12 volt battery.

It wasn't sulphated, then.

--
*What hair colour do they put on the driver's license of a bald man? *

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

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

There's an American unit by Pulse tech, which claims to do the job.

Or, for fraction of the price...
http://www.courtiestown.co.uk/batteries/shop.htm

"Grimly Curmudgeon" wrote in message
...
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember John Williamson
saying something like:

There's an American unit by Pulse tech, which claims to do the job.

Or, for fraction of the price...
http://www.courtiestown.co.uk/batteries/shop.htm



BUY AMERICAN. WE GET THE JOB DONE.