Recovering a dead battery

[Fast Eddy]

In the "you learn something new every day" category...

My batteries in my truck got discharged a couple times lately. I pulled them out and individually charged them only to find that one of them would only get up to about 6v. Normally this is when I'd head to Sears and replace them both.

A guy told me I could recover it by taking out the acid and spraying out the gunk. Sure enough, that dead old POS is now a happy 13v and fired my big diesel first crank after an overnight trickle charge.

Next time they go dead, I'm going to do it again and replace the fluid. It was pretty dark; dirty.

 

[snobdds]

What did you do with the battery acid?

 

[Fast Eddy]

Poured it into two xl McD's cups, then put it back into the battery. Spilled just a little and topped it off with water.

It's easy to dispose of. You put it in a bucket and mix in baking soda until it stops bubbling.

 

[alia176]

Poured it into two xl McD's cups, then put it back into the battery. Spilled just a little and topped it off with water.

It's easy to dispose of. You put it in a bucket and mix in baking soda until it stops bubbling.

Ok, I don't get it. You took out the battery acid and then poured it back into the same battery and now it works great?

 

[e9999]

I suspect that one way batteries go bad is when lead particulates fall off the plates and cover the bottom, shortcircuiting things up. If so, it's not entirely surprising that removing the gunk there could help things out. OTOH, once it's gone it's gone off the plates too so it's probably living on borrowed time.

(I do hope for your sake that you took serious precautions with the acid. McD cups, really?)

 

[spotcruiser]

Exactly. Sludge is not good for batteries. Submarines have a battery aeration system to prolong the life of the cells. A small pump supplies air to the bottom of each cell, preventing stratification of the electrolyte and keeping particles that would form sludge suspended in the electrolyte.

I suspect that one way batteries go bad is when lead particulates fall off the plates and cover the bottom, shortcircuiting things up. If so, it's not entirely surprising that removing the gunk there could help things out.

 

[AimCOtaco]

It's easy to dispose of. You put it in a bucket and mix in baking soda until it stops bubbling.

This neutralizes the acid. This does nothing for the LEAD which is toxic and must be handled and disposed of carefully. Be safe and don't get caught pouring lead solutions down the drain.


Glad you got some fresh life from the cells, you probably won't get away with that fix too many times though as the plates will ultimately go away. It's difficult to match the mass of sulfuric acid to the mass of lead on a re-fill so the life expectancy won't be the same as the cells probably won't be balanced.

It's a good way to get out of a jam or make it to next season just don't expect them to be like new from a life, capacity, or reliability standpoint. Don't get burned, don't get busted, don't get lead poisoning, and have fun!

 

[Spook50]

What did you do with the battery acid?

Hopefully poured it over the hood of an Escalade that was double parked in the handicapped spots

Saw one a few days ago, and apparently I wasn't the only one because it had been heavily keyed.

Anyhoo back on track, I've been doing a lot of reading on the causes of complete car battery death, and one of the most common factors is lead sulphate buildup on the plates that (in layman's terms) reduces the battery's ability to store power. I've got a near-dead (unusable for starting a car) battery from our Avalon that I'm going to use as a test bed and experiment with a couple "desulphating" circuits I've been picking apart that are designed to piggyback onto a low current charger. It's a slow process from what I've gathered, but more often that not, users claim that it's saved their batteries. Basically these circuits allow quick (as in millisecond) high voltage pulses to run through the battery that slowly break up the buildup and allow it to dissolve back into the acid. Some chargers claim to do this, but the cheapest I've seen that has any decent refiews is still just over $50. One of the circuits I'm looking at fits in an Altoids tin and should cost about $15-$20 bucks to make.

I've got several other projects to finish first, but once I get around to this, I'll post up whatever results I end up with.

 

[e9999]

Hopefully poured it over the hood of an Escalade that was double parked in the handicapped spots

Saw one a few days ago, and apparently I wasn't the only one because it had been heavily keyed.

Anyhoo back on track, I've been doing a lot of reading on the causes of complete car battery death, and one of the most common factors is lead sulphate buildup on the plates that (in layman's terms) reduces the battery's ability to store power. I've got a near-dead (unusable for starting a car) battery from our Avalon that I'm going to use as a test bed and experiment with a couple "desulphating" circuits I've been picking apart that are designed to piggyback onto a low current charger. It's a slow process from what I've gathered, but more often that not, users claim that it's saved their batteries. Basically these circuits allow quick (as in millisecond) high voltage pulses to run through the battery that slowly break up the buildup and allow it to dissolve back into the acid. Some chargers claim to do this, but the cheapest I've seen that has any decent refiews is still just over $50. One of the circuits I'm looking at fits in an Altoids tin and should cost about $15-$20 bucks to make.

I've got several other projects to finish first, but once I get around to this, I'll post up whatever results I end up with.

I've been using a desulfating semi-smart charger for some years now. Of course, no idea if that's doing anything in the real world... But eh, it makes me feel good... And my batteries last a long time too, so there...

 

[AimCOtaco]

I've used a Battery minder for years with some amazing results at recovering old batteries. It is a desulfating waveform trickle charger.

Best save was an old interstate my brother had been sitting on. It had been parked dead in the winter for about 4 months, it was about 8 years old. It was dead to the point that I could leave it on a 5 amp charger overnight and in the morning I could shunt the terminals with a screwdriver and barely get a spark.

3-5 days on the battery minder (Audi A4 steering rack is a long and painful job) and it was starting the car, charging normally, and I lost track of it after that so he probably got another couple of years out of it.

The thing has more than paid for itself several times. I'm a believer in desulfation.

 

[e9999]

I've used a Battery minder for years with some amazing results at recovering old batteries. It is a desulfating waveform trickle charger.

Best save was an old interstate my brother had been sitting on. It had been parked dead in the winter for about 4 months, it was about 8 years old. It was dead to the point that I could leave it on a 5 amp charger overnight and in the morning I could shunt the terminals with a screwdriver and barely get a spark.

3-5 days on the battery minder (Audi A4 steering rack is a long and painful job) and it was starting the car, charging normally, and I lost track of it after that so he probably got another couple of years out of it.

The thing has more than paid for itself several times. I'm a believer in desulfation.

Mine is a BatteryMinder (Plus) as well.
But I can't say I would expect that it would do miracles in 3-5 days. For one thing because they do in fact state explicitly IIRC that it will take a very long time (months?) to desulfate a battery. Maybe yours was a fluke or something else going on?