Batteries > Ni-Cd & NiMH

Q-4: "Several years ago I saw an article that gave tips on how to rejuvenate old Ni-Cd cells," recalled one reader. "I can't find that article today. Is there a technique that you are aware of that would bring old batteries back to functionality?" Answer ...

Q-6: "I'm concerned about your statement that any Ni-Cd cell will have a nominal (average) voltage of 1.2," commented one reader. "Then you went on in the testing discussion to say that when a four-cell receiver pack gets down to roughly 4.8 volts, it's time to recharge. I question how could the cell have an average of 1.2 volts or 4.8 volts (for four cells) and still need recharging?" Answer ...

Q-8: I noticed in your series that you refer to four- and five-cell receiver battery packs, but I have a single-cell pack rated at 4.8 volts and was wondering what voltage can it reach before needing to recharge? Answer ...

Q-13: "I have a rather expensive seven-cell Ni-Cd high-capacity battery pack that seems to have lost a lot of capacity after one year of use. How would you feel if I bought a sampling of these same cells and subjected them to all types of charging and charging techniques? I would be happy to report on my findings." Answer ...