Spektrum 800mAh 1S 3.7V 30C LiPo Battery; JST IMPORTANT LITHIUM POLYMER SAFETY INFORMATION DO NOT leave a battery in your model when charging DO NOT leave lithium batteries unattended when charging ALWAYS balance charge lithium battery ALWAYS use a LiPo Safe charging bag/box YOU MUST use a Li-Poly specific charger to charge lithium batteries (NiMH or NiCD only chargers WILL NOT WORK!) DO NOT over discharge lithium battery packs DO NOT expose batteries to sunshine or store/charge batteries at temperatures above 35C/95F or in a closed automobile. READ & UNDERSTAND the instructions carefully before operating this battery