Right... if one cell is a bit lower than another the voltage could be 4.2v + 3.8v = 8v. Or worse, who knows. You could even start out with 2 cells at identical voltage, say 3v, but one is lower capacity than the other. Mfg variation, breakdown, who knows. If they both get the same current, the lower capacity once could overcharge before the lower capacity one reaches full charge. You could have a batt that lost half its capacity due to some internal failure, overcharge, and catch fire. The initial cell prob wouldn't have resulted in a fire were it not for the failure to reg individual cell voltages. Danny John Ferrell wrote: > Each individual cell would have to be maintained at (or below) the 4 volt > limit to avoid cell damage. > > John Ferrell W8CCW > > "All that is necessary for the triumph of evil is for good men to do > nothing." -- Edmund Burke > http://DixieNC.US > > ----- Original Message ----- > From: "Michael Algernon" > To: "Microcontroller discussion list - Public." > Sent: Friday, November 21, 2008 9:37 PM > Subject: [EE]: Simple charging for stacked LION batteries > > > >> I have seen from previous posts that a LION battery can be C/10 >> charged to 4 volts if you can accept the loss of some stored energy. >> The charger could simply be a voltage limited current source. If you >> have a string of LIONs can you charge them to 4*N volts where N is the >> number of batteries ? >> MA >> >> >> WFT Electronics >> Denver, CO 720 222 1309 >> " dent the UNIVERSE " >> >> All ideas, text, drawings and audio , that are originated by WFT >> Electronics ( and it's principals ), that are included with this >> signature text are to be deemed to be released to the public domain as >> of the date of this communication . >> >> -- >> http://www.piclist.com PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> >> > > > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist