I accidentally shorted my new 1400mah 4.8V NiCd pack for several seconds. Was trying to measure the voltage with a DMM using my charge adapter cable with banana plugs on the ends, when the banana plugs touched each other (should have had my coffee first !!). Could see some arcing. The voltage seems to be OK at 5.1V and the battery temperature was normal but I am concerned if I had weakened the battery separators. Will cycling give any indication of damage ? Or is the separator tougher than I think ? Thanks for the inputs...........

I would really be concerned if the battery cells got very warm. However, for the sake of safety and peace of mind I would charge them up, discharge them then charge them up again. Compare the discharge time/capacity from full charge to the times/capacities you obtained from past discharges from full charges when you knew the batteries were fine. If there is no time/capacity difference shown from previous discharge times/capacities then you are probably fine. I don't know if the long term capacity retention has been affected. But you most likely charge then fly without an appreciable amount of time between.

Should be no problem if there was no heating or evidence of deformed wires.

As the experts say, if you didn't let the smoke out - no problem!

Red, thanks for the assurance ! Just out of interest, is there any reliability test for batteries done at Sanyo to assess the separators ? What kind of current or temperatures can the separators withstand before they are "punched through" ?

The separators act to contain the electrolyte and provide ion transfer, it is not effected by the actual current drawn from the cell other than by any heat generated. The failure mode attributable to high currents is more likely to be burn off of the internal cell roll to positive button. The separator deterioration is an oxidation issue which is a rather slow process which is accelerated by extended exposure to high temperatures.

Thanks Red. I cycled my batt and the capacity is OK, but I'll keep a close eye on it.