Rejuvenating old batteries

[Mackman]

Lots of u-tube videos out there of guys rejuvenating dead batteries. Anyone had any luck breathing new live into old batteries, and does it last? What methods did you use?

 

[davek]

 

[Rishi]

I have an old friend obsessed with this idea, and over the years, I've never seen him get more than a few weeks of (daily use) life from a lifeless battery. There have been many urban legends and modern-day youtube videos on this topic.

Considering the lead content in lead-acid batteries, they are a pain to dispose of. If there were some miracle cure for failing batteries, it should be common knowledge by this time, in our effort to make the environment better.

 

[ruffcut]

Git ya a new one an be done! Like was said, if it worked, no one would be buyin new batteries!

 

[Lefty71]

Anyone tight with corner store used car dealer?? Ask them what their battery suppliers do.... i had an old guy tell me just a few years ago he only paid $10 to renew them.... most new over the counter brand name ones were $100 then.

 

[Runner 68]

 

[dostroupe]

I boiled my lawnmower battery in the spring of '23, just to see if it works. I got on it Sunday to chop up some leaves and had to boost it off. So, 2 1/2 summers, not to bad. I boiled it with my big battery charger set to starting amps, 200amps I think. I'll be buying a new one in the spring.

 

[AR67GTX]

A little off topic but when my batteries get up in age I will usually pop the caps or plates off and finding some or all cells low on water, top off the cells with distilled water hoping to get another 6 months or so out of it. This seems to be what most references suggest you do. However my experience seems to be that this just speeds up the battery failure. I checked my wife’s 4-1/2 year old battery in her car a couple weeks ago - still starting fine - and all the cells were low. Filled them up with distilled water and a week later she went out to start it and it was suddenly down to 10 volts static, which doesn’t work well with modern, electronics laden cars. So I guess I’ll just leave them alone in the future to die a natural death.

 

[YY1]

Let me see if I got this.....

A used car dealer routinely "reconditioned" batteries using methods that have been known to last "a few months, tops"??

Can't say I'm the least bit surprised.

 

[RJRENTON]

Git ya a new one an be done! Like was said, if it worked, no one would be buyin new batteries!

My philosophy.......the battery gets one chance NOT to start the car......then it gets REPLACED, with an equal or one with more amp hours / more Cold Cranking Amps capacity. Just quit "fiddlily ******* around" AND BUY a new battery......it's just not worth the hassle coaxing an old dead battery one more time.....it'll let you down at the least opportune time......just my opinion of course.....
BOB RENTON

 

[Runner 68]

My philosophy.......the battery gets one chance NOT to start the car......then it gets REPLACED, with an equal or one with more amp hours / more Cold Cranking Amps capacity. Just quit "fiddlily ******* around" AND BUY a new battery......it's just not worth the hassle coaxing an old dead battery one more time.....it'll let you down at the least opportune time......just my opinion of course.....
BOB RENTON

Bravo. Well stated Bob. Couldn't agree more.

 

[62 Dart Convertible]

Batteries have several different failure modes, so these urban myth "fixes" will work sometimes and not others. My last battery that failed was not that old, and went from fully charged and cranking fine, to unable to supply enough current to power the interior light (like an hour later) - likely a failed inter-cell connection. Nothing can fix that.

 

[66Newport]

I know that modern "smart" battery chargers tend to fail out batteries prematurely so that you'll buy a new one. People just toss them not knowing they can be saved. I have resuscitated many (not all) batteries from our local dump; everything from car/lawn&garden down to alkaline batteries.. I have brought 12V batteries back from reading 8 volts. Case in point, my dad's electric wheel chair. No smart charger would charge the two 12V batteries. Kept failing them out. I hooked each one to a 12v car battery for under 30 min but not straight on. I have a switching circuit at about 30 percent duty cycle.. Voltage came up to 12.1 and at that point the smart charger will charge it without failing it.. It saved those batteries on the first try.

 

[Lefty71]

Batteries have several different failure modes, so these urban myth "fixes" will work sometimes and not others. My last battery that failed was not that old, and went from fully charged and cranking fine, to unable to supply enough current to power the interior light (like an hour later) - likely a failed inter-cell connection. Nothing can fix that.

I ruined one in a pickup truck jerking out a tree stump once.....one jerk too hard, truck stalled. Battery was dead, right now, just like that. I assume you knock any crud loose and it shorts the cells at the bottom, it's toast unless you know some method of flushing the crud out.