Help: Li-poly discharge question
Posted this in "batteries" got no response. Perhaps this is a better forum:
For use on Li-ion (converted new cell-phone batteries) and li-poly battery packs in my indoor electric airplanes....
Knowing that these cells are particular to minimum discharge voltage, at the expense of a little weight, I am building a small circuit board that can monitor voltage through discharge and turn on an LED when the pack reaches "X" voltage to signal it is time to land. I've got the circuit built up and it is very stable at room temperature (triggers EVERY time at "set" voltage - no drift - with a lab power supply)
So to those experts out there (Red, please, included!!!): What would be a good reasonable voltage discharge threshold that would cover both types of cells?
My gut says a safe minimum would be 5.0V for a two-cell pack, but I've read somewhere that you can safely push these cells to 2.25V/cell, so something possibly closer to 4.5V/pack would be appropriate.
I'll post the circuit if someone asks, and perhaps a photo of the hard-wired prototype board to give an idea of the size/weight....
Thanks in advance...
Roger