[header] How to lengthen rc battery life [title] Wait at least 15-20 minutes after you drain a battery to charge it. [step] This allows the battery to cool down before each charge cycle. [substeps] Make sure the battery is cool to the touch before charging it again, but 15 minutes should be alright. 
[title] Know what is considered hot for a battery. [step] If the battery is hot after use, then it is a good sign that your battery is getting old.