msb@lsuc.UUCP (Mark Brader) (07/06/85)
> A solution to this problem is occasionally to let the battery discharge > completely, e.g. by leaving the batteries in a radio that's on for a day, > and then recharging them completely. ... This is safe for NiCd CELLS, but you have to be careful doing it with BATTERIES, i.e., two or more cells in series, which is to say, what you use in most applications. See, if one of the two cells is weaker than the other, and it runs out first, the current forced through it by the stronger cell can ruin the weaker one permanently. I'm still using the HP-21 calculator I bought in 1976 (I think it's The Perfect Calculator, and am sorry to see it disappear); its "battery pack" consists of two NiCd's, about AA size, in a plastic cartridge. About 5 times during its life I've left it turned on for a long time, so that the battery discharged completely, and on at least 3 of those occasions I then had to go out and buy another battery pack. (Fortunately, they still sell them.) When I wanted to discharge the NiCd D-cells I use in my bicycle lights, I wired each one across a separate resistance (light bulb). No trouble. Mark Brader