so basically unattended they are fine being unused. When charging I think I would only have to worry about them when they are getting hot. The ones I have charged never really get warm. I always balance them when charging thou, My hyperion charger does basically eveything for me. All I do is set it 2s and the correct mah which I have are 1600 and one 5000mah and the charger sets the amps. If I do all that correctly I should be ok right?