Extend your NiMH battery pack life with the following practices: Fully recharge your new battery pack when you first receive it. rDo not over-discharge the battery, stop using it when you notice a drop in performance. Do not over-charge the battery, remove the battery from charger when you are done recharging. Heat lowers battery life, do not charge or discharge the battery when it's hot. Always let the batteries cool down to room temp before using it/charging it. Do not store the battery with low voltage, recharge after each use to avoid over-discharge. Always store the battery in a dry and cool place, never expose it to heat or direct sunlight. Recharge the battery once every 6-month, if they will be unused or stored long term. WARNING - DO NOT CHARGE LiPO Batteries： DO NOT CHARGE: if the label on your battery says: LiPO, LIPO, Li-Po, LI-PO, Li-Polymer, Li-Poly, Lithium Polymer, Li-ion, Lithium-Ion, Lithium. Caution: LiPO battery packs may often have two sets of leads/connectors - do not charge if identified as LiPO battery. Failure to follow these warnings may result in fire or personal injury. Contact our customer support team if you are unsure if your battery can be charged.