Is my battery shot?

The stuff I was building the chargers for didn't have the luxury of
getting the last gasp out of a battery - we had minimum backup life we
had to guarentee. Most of mine would try a rescue then run a
controlled discharge to measure capacity followed by a leakage run.
It the controller reported failure of either one it notified a control
center and a replacement was scheduled. After several years of
messing with this stuff we wound up using very high current spikes
followed by a cooling period for the initial recharge. The protocol
varied with the battery, but it was something like 100 msec at 10x
rated charge current using a 5% duty cycle. Fun stuff - got to spray
batteries all over a test cell <g>. Made me very cautious around
charging batteries.

On Thu, 3 Mar 2005 18:03:18 UTC Rich Hampel >
wrote:

> But you cant equalize a gel battery ... or you blow out the pressure
> valve. I simply turn them upside down and slow charge them back to
> recovery.
>
> In article >, Will Honea
> > wrote:
>
> > I have designed and built such chargers for industrial and
> > instrumentation batteries - some the size of your Jeep - and there is
> > a caveat to all these processes: success rate even in lead-acid (or
> > Gel equivilants) designed for deep discharge is at best 75% for one
> > day sitting dead. That goes down rapidly with each day it sits.
> > After 4 days, getting even one back to a functional state is a
> > surprise. Also look at the cost and what you have even if it does
> > work. Sometimes it's cheaper and a lot more reliable to bite the
> > bullet and get a new one if there is any doubt.
> >
> > On Wed, 2 Mar 2005 19:37:52 UTC Rich Hampel >
> > wrote:
> >
> > > If you left the battery fully discharged for more than one or two days.
> > > take the battery to an auto-electric speicalty shop and have them
> > > 'equalize' it. When you ask to have it done and the counter man has a
> > > strange look on his face, leave the shop.
> > >
> > > Equalization is controlled over-charging (at a precise voltage ... and
> > > correlated to actual battery temperature) will help to desulphanate the
> > > plates, Batteries that are left in a dead state for more than one to
> > > two days will sulphanate which will lead to premature battery failure.
> > > Equalization is done by applying a specific charge rate that causes the
> > > battery to 'boil'. Obviously dont do this yourself as you may explode
> > > the battery in the process, etc.
> > >
> > > A rapid fast full charge (turn the charger switch to 'manual' ), will
> > > sometimes be good enough. Do this outside and with plenty of 'space'
> > > so if the battery 'goes' noone gets hurt. Hook up charger, switch to
> > > manual, follow looooooong extension cord to power source and plug in.
> > > Dont even think of going near the battery when its fast manual charging
> > > in case it goes booooooom. Charge for about an hour, turn off charger
> > > and if battery is less than hot to touch, switch to automatic, etc.
> > >
> > > There are three stage solid state (expensive) external regulators that
> > > allow for equalization ... but again if you dont know what you are
> > > doing, you can get seriously hurt.
> > >
> > > In article >, nds
> > > > wrote:
> > >
> > > > The battery may survive. Suggest setting battery charger to 6 volt setting
> > > > and when charge rate drops below 2 amps set to 12 volts and continue to
> > > > charge.
> > > >
> > > > "Greg" > wrote in message
> > > > news:nBpUd.519892$8l.226545@pd7tw1no...
> > > > > I park my CJ in one of those 10'x20' grey plastic garages, was out
> > > > > wheeling last sunday, and obviously I forgot to turn off lights, battery
> > > > so
> > > > > dead not even a click, stuck camper battery in and on come lights. So
> > > > > question is, had CJ for 1 1/2 years, battery of unknown age, one of
> > > > > those
> > > > > ones with green lights, ( no green there today ), is it worth trying to
> > > > > charge it or is it shot? I've had dead batteries before, but not ones
> > > > > that
> > > > > dead, 7 days of headlights on, so I don't know if a non deap cycle battery
> > > > > can come back from that.
> > > > >
> > > > >
> > > >
> > > >


--
Will Honea

give me the date code from your bat & i will tell you how old it is
or, take a look at this link & scroll down to question 4
http://www.autobatteries.com/faq/index.asp
either way, out of curiosity, let us know the age
warning: this does not work for all bats. it definitely works on johnson
controls branded bats
(more than a dozen brands, depending on where they are sold, so chances are
good)
but delco & possible others uses diffr scheme for their bats
to see a list of johnson controls batteries follow this link
http://www.autobatteries.com/brands/index.asp
take out common vehicle mfr's out the door - what's left is johnson's own
brands

btw. in case you don't know www.autobatteries.com has been started & is
maintained by johnson controls...


"Greg" > wrote in message
news:nBpUd.519892$8l.226545@pd7tw1no...
| I park my CJ in one of those 10'x20' grey plastic garages, was out
| wheeling last sunday, and obviously I forgot to turn off lights, battery
so
| dead not even a click, stuck camper battery in and on come lights. So
| question is, had CJ for 1 1/2 years, battery of unknown age, one of those
| ones with green lights, ( no green there today ), is it worth trying to
| charge it or is it shot? I've had dead batteries before, but not ones that
| dead, 7 days of headlights on, so I don't know if a non deap cycle battery
| can come back from that.
|
|

It might well come back, as long as it didn't freeze, but I think you'll
find that it'll take a fairly serious charger to make it happen. When a
battery sits dead for very long the plates change and become harder to
put a charge into. Here's a link that explains it, to some degree..

http://www.flex.com/~kalepa/technotes.htm

Read under the heading "Charge".

Good luck,

John





nds wrote:
> The battery may survive. Suggest setting battery charger to 6 volt setting
> and when charge rate drops below 2 amps set to 12 volts and continue to
> charge.
>
> "Greg" > wrote in message
> news:nBpUd.519892$8l.226545@pd7tw1no...
>
>> I park my CJ in one of those 10'x20' grey plastic garages, was out
>>wheeling last sunday, and obviously I forgot to turn off lights, battery
>
> so
>
>>dead not even a click, stuck camper battery in and on come lights. So
>>question is, had CJ for 1 1/2 years, battery of unknown age, one of those
>>ones with green lights, ( no green there today ), is it worth trying to
>>charge it or is it shot? I've had dead batteries before, but not ones that
>>dead, 7 days of headlights on, so I don't know if a non deap cycle battery
>>can come back from that.
>>
>>
>
>
>

Rich,
Good post.
Steve