Breathing new life in laptop batteries

<The first thing to try is to charge a large electrolytic capacitor <(say 10000-100000 uF) to about 20V. Now discharge it through the faulty <cell. If you are lucky, the cell voltage will rise, at which point charge <the cell as above. This is the beast bet as cells fail with internal shorts and the cap will dump enough energy to open them without cooking the cell. <What you do is use a current limited PSU of about 10V and 8A. 'Blip' it <across the cell for a fraction of a second - just tap the wires on. This is ok if the cell is hard starting, I don't recommend it. The better approach is the LARGE cap charged to 12-20V and follow with 1/4 the cell capacity for a few minutes (NOT LONGER). <I have seen one article which suggests doing the same thing with a car <battery as the power supply. DON'T!!! . The current is far too high, and <the NiCd is likely to explode. Extremely dangerous. <manufacturers used standard-sized cells, so it is possible to rebuild old <battery packs. Often far cheaper than a new one. Allison