Ok....I have a "method" or "process" of charging that has worked for me for a long, long time!!! However, I now have newer peak chargers and they do not trickle charge like my old "timer" charger. Plus, I've been reading all about these "wall mart" chargers and how to hook them up to a 24 hour timer. Is there some "tech formulas/equations" for charging batts if I were to use wall mart chargers? I have 7.2v 1500 and 1800 Nicds. I found some old wall chargers and here is what they say..... 1) 9v DC 600mA 2) 9v DC 200mA Those are the ones that I have found, but what if I found another....like a 12v or 10v or something like that. I would guess that the formulas will answer that......correct?