FWIW, I've charged batteries on a VP2 and a VP4 at 1 amp and after the charge cycle is done, the batteries are barely warm. So charging them at 1 amp isn't going to overload the battery. When I'm in a rush, I'll charge them at 1 amp. When I'm not in a rush, I'll charge them at 0.5 amp. I've never charged them using the 0.25 amp setting.