OK, so I've seen the light, tossing all of the old NiMh batteries and switching over to Life batteries. Found some inexpensive ones at Value Hobby and thought I'd give them a try (
GForce 5C 1500mAh 2S 6.6V LiFe RX Pack - LiFe Batteries - Batteries - Power | Value Hobby ). Ordered several and charged them up. Charger cut off at 7.19 or 7.2 each time. While checking the cell balance noticed that the (collective) voltage was falling even as I was checking the balance charge directly off the charger. Five packs. After a bit, maybe a couple of hrs or so, every one was down to somewhere in the neighborhood of low 6.8something to high 6.7 something.. OK, so I thought first charge, let's balance charge them. Well, same results. OK, let's try cycling them. Even after reading thru several threads not sure of safe cutoff voltage so chose 6.4V. end of charge/cycle, same results for all packs. Unfortunately didn't keep track of MA discharged or put back in but it wasn't near advertised capacity.
First, is it normal for overall voltage to fall that quickly?
Second, what is a good/recommended cutoff voltage for cycling these cells?
Third, what is an acceptable spread between cells when balancing?
Haven't been able to get the vendor to answer their phone line so no help there.
Oh yeah, these "packs" seem to be made up of two cylindrical cells (like NiMh) as opposed to a more flat pack.
Are these cells useable/reliable for aircraft use and, if so, what is the best maintenance/check procedure.
TIA for your insight.
G42