Anyone try to rejuvenate a lead acid battery?

[Disaffected]

I have a couple of lawn tractor batteries that appear to be sulfated (normal voltage but will not take a very large charge). There appear to be a couple of methods to rejuvenate them but I'm skeptical they work.

One is the battery "desulfator", an electrical gadget you connect to the terminals and it sends voltage pulses into the battery that supposedly remove the lead sulfate coating that has built up on the plates.

Another is a chemical procedure in which the liquid from the battery is drained and the battery is flushed with a baking soda solution. A concentrated solution of Epsom salts (magnesium sulfate) is then added and the battery is recharged/discharged a few times to supposedly restore it.

[mahatmakanejeeves]

1. Yes, years ago. It was a waste of time.

I flushed an automotive one out with distilled water. It might work for you, but it didn't work for me.

Car batteries were a lot cheaper back then, which was 1981.

[Disaffected]

3. Yes but did you

replace the distilled water with anything after flushing?

[mahatmakanejeeves]

6. Yes, electrolyte. It still didn't work. NT

[Alpeduez21]

2. A lawn mower battery is $60 bucks tops at least round here.

Depending on the engine I can get one for $40.

Those ideas are iffy at best. My time is more valuable than that. It's a fun experiment to try. I'd love to hear your results. I've not had success.

[Disaffected]

4. Hey, I have the time and

I adhere to the reuse rather than recycle philosophy. I see mixed results reported on the intertubes but, a lot of the failures come from batteries that are shorted internally or are too far gone/old to be revived (these things only work for sulfated batteries that are otherwise intact)>

Anyhow, I have ordered a "desulfator" gadget and will try it & report back (may be a while though as they apparently can take a week or two to work).

[mahatmakanejeeves]

7. Supposedly, you can dislodge the internal shorts by firmly lowering (NOT DROPPING) the

battery onto a sidewalk. That will cause the little tendrils to fall apart.

You do not want to lower the battery so abruptly that you cause the case to split.

[Marthe48]

5. A story from the good old days

My mother-in-law was too embarassed to tell the whole story and my brother-in-law finished it for her.

Her family lived on a farm in rural WV, in the 30s. They had a radio, and it ran on a battery they kept outside. Somehow, they heard that you could extend the life of the battery if somebody peed on it. So her brothers would pee on the battery to keep the radio going, until their parents got the money and ordered a new battery.

I don't know what kind of a battery it was, and have no idea what sort of chemical reaction occurred.

[NBachers]

9. I've heard you can keep electric fences in good operating order by peeing on them.

[EYESORE 9001]

10. That method also tests the electric fence audible alarm

It sounds very much like a scream.

[relayerbob]

8. Let the pros do it

There are MANY companies who recyulce the batteries properly and safely, and without disposing chemicals into the environment improperly. For example:

https://www.batteryrecyclersofamerica.com/lead-acid-battery-recycling/

[Wounded Bear]

13. Yeah, recycle it and go new...

recovering lead acid batteries can be dangerous. Nasty chemicals involved and the chance of explosions.

[MichMan]

11. Many battery chargers/maintainers have a periodic sulfation mode

[Major Nikon]

14. I think that's more for prevention rather than correction

I tried using mine once to restore a battery and it didn't work, but it's possible there were other issues.

The best maintenance for batteries that see little use is a good float/equalize charger commonly sold as battery maintainers which is what they are designed to do.

[taxi]

12. With small lead acid batteries

of 20ah (amp hours or less) found in mowers, motorcycles, and scooters there isn't much that can be done when the voltage is good but the current is low. Check the voltage drop first. With the key off, connect and leave connected a meter for the voltage. Next turn the key on and re-read the voltage. If the voltage drops much below 12 volts there isn't much you can do, the lead connecting the posts to the cells may be cracked and won't carry enough current. If the voltage doesn't drop dramatically in this test, increase the load by turning something on like a headlight. If the voltage remains fairly high watch the meter while engaging the starter. If the voltage remains high in all these tests the problem is elsewhere, perhaps in one of the cables. Twisting of the post often causes this condition - it cracks the lead connector to a post and is often caused by over tightening the cables or movement of an unfastened battery.

eta: connect the meter directly to the battery posts for this test