Elite Force 8.4 3800 mAh NiMH Nunchuck Airsoft Battery Great for beginner or low end guns, not recommended for most higher end guns as you will be under power your AEG's motor, which could cause failure of the motor. NiMh battery safety instructions:• Store batteries carefully. Do not store batteries in a manner that allows the terminals to short circuit. Store batteries at temperatures below 90 degrees Fahrenheit and above 40 degrees Fahrenheit. Do not place batteries near heat sources or expose to direct sunlight for long periods of time. Elevated temperatures may shorten the service life of the battery. Use NiMh battery chargers of the appropriate voltage when charging. Follow instructions provided by the battery charger. An improperly charged battery may cause a fire as well as damage to the battery. Do not disassemble a NiMh battery. If battery is unintentionally destroyed, use thick rubber gloves to handle battery contents and avoid inhalation of vapors that may be emitted. Do not short circuit a NiMh battery. Short circuits can overheat the terminals and may cause a fire. Extended short circuiting creates high temperatures at the terminals and may cause skin burns if touched. Extended short circuiting also may also cause a battery cell to ignite and release gas. Do not reverse cell polarity. Reversing cell polarity may cause the battery to ignite and cause a fire. Avoid using old & new battery cells of different sizes, chemistry or types in the same battery assembly.