Originally Posted by crusey_aus
Awaiting delivery of my unit
When should I be taking readings ?
Before charging, after charging, when stored at storage voltage ?
Anytime really. Slightly surprisingly, the IR of a lipo pack is almost independant of charge state until the charge is virtually depleted. Obviously if the cell has no stored energy left then any load will collapse the voltage, but until that point is reached the IR seems to be virtually constant.
Provided you are careful to measure IR at a fixed temperature, it is the best guide to what is a good or bad lipo and correlates with best performance in practical flying, ie in the ability to deliver max power to the motor with minimum temperature rise.