WE may be talking about accucels, but IMO Hyperions are still top of the line, the 610I Duo that I use gets 2 of my zippys at 4.2 per cell for all 3 cells on all 4 packs takes it 90min's with a 90% charge parallel them to a stock revo and get 35min runtime b4 the LVC cutsd it off.
I have a Accucel-6 and a pr of 0610i chargers, can't compare a $170 charger to a $38 charger. Can't beat the Accucell for a pit bag charger and taking it with you though, its been amazing for a $38 charger.
The Accucel-6 is only a 50watt charger and thats some of what you're running into, so its just going to take a while to charge and balance. You need to factor that into resetting the safety timer.