On 10/18/2011 2:35 PM, V G wrote: > On Tue, Oct 18, 2011 at 8:33 AM, Mark Hancheywrot= e: > >> I went the PIC route for a battery charger. It wasn't the lowest part >> count though. Each battery is charged to get the max charge . It has a >> routine where the batteries charge for a period of time, about 10 >> minutes, then are switched off, allowed to rest for 20 seconds and then >> the voltage checked with a load switched in by the PIC. Each battery is >> connected to a separate ADC on the PIC and if below the limit is charged >> more. The great thing about this setup is that it never heats up the >> batteries much during the charging routine and the run time on the >> batteries is longer than with any charger I had used before. >> >> > I thought about this method before, but never went through with it. I'm > assuming you're talking about NiMH. What voltage threshold did you use? I used 1.28 for the voltage under load with a 100ohm resistor switched=20 through a FET. The method of charging is called burp charging, there is a NASA paper on=20 it where they use very short charge and rest periods , only ms long. http://dnd.hu/letoltes/AdvanceTec_whitepaper.pdf It works well and the batteries don't wear out as often. Mark --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .