AO: you can run batteries forever without zapping them, or you can zap them occasionally. so far i've done my packs twice this season (all most over). the idea is that shoving big voltage in to the cells will breakup cemical residue & lower the internal resistance of the cell, this in turn will allow the cells to produce increased voltage. it works, the first time i used it i did some pana 3000s, the pack (6 cells) gained 1volt after zapping.
SMASH: the zapper we use is adjustable in voltage, 30v- 90v. the amperage i do not know, i wouldn't recomend putting a multimeter in between it and a cell to measure amperage, i'd bet the meter would get toasted. the only why you MAY BE ABLE to measure the amperage is with a "clamp-on" amp meter, they are used for high amperage situations, still i'm not confident this would work (AKA, i ain't trying it). 90volts, a meter, and a single sub-c cell could get dangerous quick! as for the timing, the zapper dumps the voltage to the cell within a few milliseconds. it basiclly connects a large, charged capacitor to a single cell at the flip of a switch. it's pretty serious stuff, if you don't get the contacts just right you'll know it in a hurry, it arcs voltage like lighting & sounds like a handgun firing, you're left with a blackened half-zapped cell.