How many amps are you charging at?
the 1100 packs are sensitive, you can't hammer them like 4-5 amps,,
I never charge mine at more than 1.5 amps,,it ussually takes about 15min to go from 6volts to peak 6.6-6.7 comming off peak

I use this charger for my Tx/Rx and glow driver
it works great,,never over peaks

Hitec 335