moroney@jon.DEC (11/10/84)
Here's a trick from an elecronics magazine (73, I believe) which may save a lot of people a fair chunk of money in new Nicads. If you have a cell with an internal short (due to reverse charging or just age) it is possible to save it by "blasting" the internal short. What you do is get a capacitor of about 1000-5000 microfarads, charge it up to about 12 volts, and then discharge it through the bad cell. (If you don't know what I am talking about, find someone who knows electronics.) This will produce a brief high-current surge of current which internally vaporizes the crystal which shorted the cell, which can then be charged in the normal manner (although it will have a reduced output, and will discharge faster) Of course, only do this to "hopeless" cases, (cells destined for the garbage can) as it is harmful to good cells. Also, don't do this to a whole string, but a single cell at a time. Hope this trick helps you as much as it has helped me. Mike Moroney ..decwrl!rhea!jon!moroney