Surging old cells back to life

[Supersleeper]

I'm sure this will spark a lot of grief, flames, what have you... lol, which is fine by me, have fun ...

I've found various posts elsewhere, but not here regarding surging cells to bring them back to life, somewhat. They would not be expected to perform as new, but could be placed in low-power devices such as clocks, infrared remotes, etc. I've actually tested this, and it appears to work on nmh and li-ion so far. I know li-ion can be dangerous to do this, so all safety precautions taken as necessary, of course.

With Li-ion, I've found that simply placing a fully charged cell in parallel to a li-ion battery can sometimes revive it enough to be able to charge. Now the real test is to see what life is actually left in them after a full charge...

 

[bowlofsalad]

I don't mean any offense, but I don't understand the point of your post.

drkangel has done plenty of what you mention. I believe his statement was that you fully charge the cell, and let it sit for something like 24 hours, if it doesn't hold the charge, it's probably garbage or dangerous. Read http://endless-sphere.com/forums/viewtopic.php?f=14&t=26383

 

[Supersleeper]

I don't mean any offense, but I don't understand the point of your post.

Nothing, other than it can be done, and I didn't see any threads dedicated to the subject, so I'm not sure what research had already been done.

 

[dogman dan]

Yeah, safety precautions would be a good idea, for connecting a cell of any kind at 0v, to one that's charged.

If I understand what you are talking about, you are referring to the way a very low lithium cell is not allowed to be charged by a good lithium charger. So somehow, you have to bring it up in voltage enough with a dumb charger, before you can resume a charge with a smart charger.

The often used approach is a slow low amperage power supply, like a cell phone charger or such. No surge is needed, just a power supply that is not shutting off. Slowly, at less than an amp, you are charging it up enough to be put on the smart charger.

Just hooking a discharged battery to a charged one, you cannot control that surge, and in some cases you could end up with quite a pop. Do wear your lab safety glasses, if not stand behind a blast shield.

That said, there is another application for surging a battery, and I have to confess to having done it by connecting a discharged battery to another. Lead and or NiCad batteries can be revived some by the use of surges to break up crystals. Some chargers will have this built into them. So in absence of a device to do this, I have pulsed nicads by connecting them to charged ones, in very brief pulses. No connection lasts long enough to burst a cell. Manually, this is quite tedious, but nothing is gained by connecting them for longer than a half second at a time. I have temporarily revived NiCad this way, but the effect is very short lived, and the crystals that short the cell just grow back soon since they are never completely removed.

 

[Punx0r]

There's the old trick of zapping nicds with a mig welder. Someone should try this with lipo...

 

[dogman dan]

With the go pro running of course. I keep meaning to do something like that with my puffed lipos. But I do live in the city, and don't want to talk to cops for having too much fun in a residential neighborhood.

 

[Ykick]

With the go pro running of course. I keep meaning to do something like that with my puffed lipos. But I do live in the city, and don't want to talk to cops for having too much fun in a residential neighborhood.

Me too, I've gotta good pile of various loose 5Ah cells but no way in hell 'can figure out a way to video testing carnage here in the land of Bloomberg! Ugh...

 

[dogman dan]

I'm just too lazy to load up the generator, go out to the desert, and do it. No plug for the welder out at the shooting spot.

 

[wineboyrider]

With the go pro running of course. I keep meaning to do something like that with my puffed lipos. But I do live in the city, and don't want to talk to cops for having too much fun in a residential neighborhood.

Me too, I've gotta good pile of various loose 5Ah cells but no way in hell 'can figure out a way to video testing carnage here in the land of Bloomberg! Ugh...

Make sure you do it while buying an illegal Big Gulp! LOL

 

[Ykick]

With the go pro running of course. I keep meaning to do something like that with my puffed lipos. But I do live in the city, and don't want to talk to cops for having too much fun in a residential neighborhood.

Me too, I've gotta good pile of various loose 5Ah cells but no way in hell 'can figure out a way to video testing carnage here in the land of Bloomberg! Ugh...

Make sure you do it while buying an illegal Big Gulp! LOL

Seriously!

I'd love to do some experiments (safely) but I can't think of anyplace that wouldn't have FDNY-NYPD sending me a bill....

Tempted to ship some of the better cells back to CA where at least I have a yard but, shipping?

Maybe I'll just connect a bulb, drain to 0V then take 'em to the recycler - where I'm sure they'll shake me down for some chump change...

 

[999zip999]

Bring them down to zero and put them in a bucket of salt water for a sure death and then to the recycler.