When I am charging my EP1500 the night before of the day of, I charge it at .5 amps. When I am at the track and have something to do, 1 amp. If I am in a time cruch 1C or 1.5 amps. I have the peak sens. set at 6mV and 50mA trickle. So, for the bigger batteries I would charge the Stickman at 2 amps or so, normally charging it at 1 amp. A little guage you can do, when you need to recharge it, put it on for 1 amp (any of them) and when the battery is done, feel how warm it is. It should be warm, but not hot to your finger. Do this when you battery is cool too.