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Topic: Charging batteries in series in an Arduino Fio (Read 1 time) previous topic - next topic

Almost Scientific

Hi --

I've got an Arduino Fio that I'd like to use with two identical LiPo batteries wired in series. Can anyone see any problems with trying to charge the two batteries at once via the USB power on the board?

retrolefty

#1
Jan 31, 2011, 01:12 am Last Edit: Jan 31, 2011, 01:14 am by retrolefty Reason: 1
Yes, I see a possible problem. Li-po cells need special charging circuits that start out as a constant current charging mode and then switch to a constant voltage mode to top off the charge. How do you propose to charge a 2 cell series connected li-po battery with USB +5vdc voltage? A two cell series connected Li-po battery, fully charged has a 8.4 vdc terminal voltage and should never be allowed to discharge below 6vdc.

Li-po are great batteries with the highest energy density per weight available. However they have special needs in charging and in prevent over-discharging. Ignoring their special requirements results in fire and/or dead cells.


Lefty

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