fordke@infonode.ingr.com (Keith Ford x8614) (11/07/90)
I once worked for a fellow who showed me a way to revive a nicad battery. I think it involved pumping a high current through for a few seconds. Can anyone expand on this or provide other useful information. Please email if possible. Thanks! -kef/MM- -- | ...!uunet!ingr!fordke OR fordke@ingr.com | Micro Magic BBS (Fidonet: 1:373/12, MaBell: +1 205 830 2362) | "and the Trees are all kept equal by hatchet, axe, and saw." -Rush
gene@cooper.cooper.EDU (Gene (the Spook) ) (11/09/90)
in article <1990Nov6.195112.11285@infonode.ingr.com>, fordke@infonode.ingr.com (Keith Ford x8614) says: > > I once worked for a fellow who showed me a way to revive a nicad > battery. I think it involved pumping a high current through for > a few seconds. Can anyone expand on this or provide other useful > information. Please email if possible. Thanks! -kef/MM- To get rid of a short, you can "zap" the NiCd from a capacitor and a higher-than-normal voltage source, just as you described. A few thousand microfarads and about 6V or so would probably be enough to blow the short like a fuse. When NiCds "forget" that they were charged, usually from being lightly discharged and then recharged, over and over, the best way to "fix" that is to deep-discharge the cell almost down to nothing, and then *slowly* recharge it at about half to a quarter of its usual charging current, and then repeat this deep-discharge/slow-recharge cycle twice or thrice. Hope this helps some... Spookfully yours, Gene
kronstad@tortoise.cis.ohio-state.edu (richard b kronstad) (11/11/90)
I have revived a couple of Nicads myself. basically you want to charge up a capacitor (try samller ones at first -1 uF) up to over 100 volts with a DC source. An AC source (such as a wall socket) will work as long as the capacitor is NOT ELECTROLYTIC (I blew a few up myself - nice blue glow) and the capacitor is rated WELL ABOVE 200 volts since you will cause a lot of current to flow - Come to think of it I DON"T RECOMMEND USING A WALL SOCKET! CHarge up the capacitor using a transformer and rectified at around 150 volts. Remove the capacitor (carefully - it could be a shoking experience if you touch the leads) and connect the diode "-" side to the Nicad "-" side and do the same with the "+" sides. You might see a spark, but that's allright because you want to spike the battery with an instant high current to break the crystals which cause a battery to die. The capacitor is necessary so that the total amount of electrons flowing is instantaneous and then nothing. I have noticed that is you have spiked a Nicad once or twice it should work again - not quite up to new capacity but it will work. Because the Nicad already had grown crystals spiking the Nicad will revive the batter but it is only a matter of time for the crystals to grow back causing the battery to die again. I hope this helped, I can't be responsible for your getting shocked but just be carefull not to touch anything high voltage - expecially the DC from a transformer!