Get a Cellpro 4S charger. It has a setting that will charge the pack to 50%. It will also balance the battery as it charges. It has got to be the most user-friendly charger on earth. You just plug in the battery and let it do its thing. On top of that, you can charge your packs at 2C and 3C if you are in a hurry without having to worry about the pack burning up. It is truly a great charger.