Customer service: All BAKTH products have a 30-day money back and 1 year warranty, if you have any problems, please contact us via email. Feature: - very long life - Powerful - High-quality fast charging - very reliable and robust Package contents: 1 x Tamiya battery Product information: - Battery type: Ni-MH (AA) - Voltage:7.2 volts - Capacity: 4000mAh - Product size: 13.3x4.7x2.4 (cm) - Product weight: 367g Cautions: - Please turn off the device when low battery to avoid deep discharge - Disconnect the battery with the device when not in use - If the battery is hot, please do not touch it until it is getting normal temperature - Keep the battery in a cool, dry place - Please charge the battery every 6 months to keep the good performance, if not use for a long time, recharge method as belowv - Charge the battery for 16 hours with 0.1 C, rest for 10 minutes, then discharge it to 1.0V at 0.2C, rest 10 minutes, finally charge it again for 0.2 minutes at 0.2 C