A lot of ni-cad packs have one or two bad cells. to find the bad one(s); unscrew the cover on the battery pack and use a voltmeter set on dc volt 2v full scale and test the cells one at a time. they should each have at least 1.25 volts. The bad cells can be removed and replaced with good cells from other discarded packs. If they're not too old many ni-cad cells will still work. You can also revive some cells by unplugging the vent hole in the top of the cell so it can breathe (seriously). Also, I have zapped single cells by momentarily connecting them one by one (even in the pack) to a car battery. plus to plus,minus to minus. But only for about a half second. Also, heating ni-cads will kill them.
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A lot of ni-cad packs have one or two bad cells. to find the bad one(s); unscrew the cover on the battery pack and use a voltmeter set on dc volt 2v full scale and test the cells one at a time. they should each have at least 1.25 volts. The bad cells can be removed and replaced with good cells from other discarded packs. If they're not too old many ni-cad cells will still work. You can also revive some cells by unplugging the vent hole in the top of the cell so it can breathe (seriously). Also, I have zapped single cells by momentarily connecting them one by one (even in the pack) to a car battery. plus to plus,minus to minus. But only for about a half second. Also, heating ni-cads will kill them.