What I've done sometimes is take a 100 uF capacitor, charge it to 4..5 times the nominal EMF of the recalcitrant cell, and discharge the capacitor to the cell, at its nominal polarity. Repeat a couple of times, and then recharge.
The procedure will either rejuvenate the cell or render it rather completely hopelessly defunct.
(no subject)
The procedure will either rejuvenate the cell or render it rather completely hopelessly defunct.