When you are charging ,you need to push the battery switch to position "I" Rechargeable 12V Lithium-ion Battery Pack is designed specifically to integrate with Light bars, Flexible LED Lights, or any 12V DC electronic device. The Lithium Ion Battery Pack can be recharged without limitations, as the battery is designed for a slow charge process (8 hours for full charge), which helps the battery pack last longer. Package content: 1x DC 12V 3000mAh Rechargeable Li-ion Battery 1x Power Cable 1x 12.6V Charger for battery NOTES Do not use the 12V lithium battery pack in places with high humidity or where it may be exposed to wet. Do not modify or disassemble the power bank. Do not throw the power bank into fire or water. Do not place the power bank during charging on flammbable materials such as in the bed or carpets.