revive a neglected battery

[Donald]

The battery in the Land Rover I was given was frozen. Not a good sign. Its thawed now. No exposed plates in the cells. No cracked case that I can see. Put on a BatteryMinder model 2012 and only the green power light came on saying it was powered on, but was not doing anything. So took that off and now have a old dumb 12V charger on it. The goal is to get it to the point where the Battery Minder can take over.

Is it toast or can I revive it?

 

[eljefino]

If your dumb charger slows way down on the amps too early, that battery sounds kaput.

Figure it's around 80 amp-hours, so a 6 amp charge should go 12 ish hours.

Battery could also be kaput other ways, but if it considers itself "full" quickly, that, too, is bad.

WM has their $48 specials.

 

[Chris142]

Once a battery freezes its junk.

 

[Donald]

The dumb charger showed zero amps going to the battery when first connected.

I know its probably a lost cause.

 

[Lubener]

Originally Posted By: Chris142
Once a battery freezes its junk.


Agree, nothing you can depend on.

 

[TFB1]

They'll sometimes come back to life, but it may take 20-24v to wake it up(at that point cut charge back to 15-16v ASAP)... Note you'll not likely to wake it up with a std charger, I used a variable power supply that will make approx 25v unloaded... It's volts that initially activate a battery, not amperage...

It did work on a long dead Delco a few years back... Came up and would start a 3.0 Aerostar, at least as long as it didn't set for more than a couple weeks... Capacity probably wasn't as much as a garden tractor battery... If it didn't light off within approx 10 seconds I'd have to jump it, or recharge battery if I wasn't in a hurry to get it going..

 

[JHZR2]

Thaw it first. There is no conductivity if the electrolyte is frozen.

 

[SrDriver]

Donald hope you can save it!

Walmart has new ones here for around $49.00 that are not bad for the price.

 

[Billbert]

1 oldtimers trick is to hook up a good battery in parallel and then slow charge it overnight (7 to ten amps) Best chance of revival.

 

[Donald]

Originally Posted By: Billbert
1 oldtimers trick is to hook up a good battery in parallel and then slow charge it overnight (7 to ten amps) Best chance of revival.


Won't there be a large flow of current from good to bad when first connected?

 

[Donald]

Originally Posted By: JHZR2
Thaw it first. There is no conductivity if the electrolyte is frozen.


I waited until it was thawed to start the revival.

 

[bullwinkle]

If you push the button on a Battery Minder it'll start the desulphation procedure without being fully charged, but it'll still continue to charge slowly.

 

[Nick1994]

Originally Posted By: eljefino
If your dumb charger slows way down on the amps too early, that battery sounds kaput.

Figure it's around 80 amp-hours, so a 6 amp charge should go 12 ish hours.

Battery could also be kaput other ways, but if it considers itself "full" quickly, that, too, is bad.

WM has their $48 specials.

I agree, sounds like a good job for a $48 Walmart battery.

I'll get one for my car when my battery dies.

 

[440Magnum]

Originally Posted By: Donald
Originally Posted By: Billbert
1 oldtimers trick is to hook up a good battery in parallel and then slow charge it overnight (7 to ten amps) Best chance of revival.


Won't there be a large flow of current from good to bad when first connected?


No, because lead-acid batteries don't accept much charging current until the applied voltage is ABOVE the open-circuit voltage. You can't really get much charge into a "dead" battery from a "good" one, although a little bit will transfer. I think the paralleling trick is more to 'fool' the charger into keeping on charging. Normally when you put a "dumb" charger on a badly sulphated battery, it'll just show full charge quickly then kick off (unless it has an 'equalize' mode you can choose, or similar). Modern multi-stage battery chargers will do a lot of this on their own without having to fool them.

That said, I think having been frozen pretty much guarantees this one is DOA. If it hadn't already been dead, it wouldn't have frozen in the first place. Double whammy... and freezing does actual physical damage.

 

[rshaw125]

On the subject of replacing the battery Duracell or Costco? I had a Walmart 'Neverlast' go out. Zero luck with Walmart batteries.
I can run into Costco or Sams. Which is the best now? I used to buy Costco, Kirkland.

 

[901Memphis]

Duracell are good because they are from East Penn. Walmart usually has a good reputation since they got rid of Exide many years ago now they are all Johnson control batteries just like you find almost everywhere. Shop by the warranty/coat you want not the brand.

 

[Donald]

Originally Posted By: bullwinkle
If you push the button on a Battery Minder it'll start the desulphation procedure without being fully charged, but it'll still continue to charge slowly.


I have one with a green button, but I have the newer (and more expensive) model (2012) attached to the battery now.

 

[wrcsixeight]

Can you take off the caps and see the plates?

It is maintaining any voltage on its own?

If it is still cold where the battery is, the charging voltage needs to be even higher to be effective.

I've seen more than one heavily discharged, albeit not frozen, battery quickly raise voltage to the high 14's with little amperage flowing, then after a minute or 2 voltage drops and amps increase to the point where I back off the voltage to lower the amperage and keep the battery from heating too much.

I use an adjustable voltage power supply with a voltmeter and ammeter attached to the output. I got tired of having to trick 'smart' chargers into doing their job.

 

[JHZR2]

Originally Posted By: Donald
Originally Posted By: JHZR2
Thaw it first. There is no conductivity if the electrolyte is frozen.


I waited until it was thawed to start the revival.


Shaken/mixed too? The concentrations will be quite different after a freeze cycle.

 

[Donald]

After a couple of hours on my dumb charger, it had enough capacity that the BatteryMinder 2012 would charge it. But the 2012 is a small charger so it will take awhile (days).