USB-C charging design: Rechargeable USB-C Lithium D battery, 3 hours fast charging. Available for direct connection to adapter, power bank and laptop for charging, can also be charged with a 5V output charger. The battery indicator flashes green when charging and stays green once fully charged. 1500 cycles: Belongs to rechargeable lithium D batteries, the cycle time can be up to about 1500 times. No need to buy a large alkaline battery. Without memory effect, cost-effective and environmentally friendly. High Power: Hixon USB C Lithium D batteries support 1.5V output. The maximum continuous working current is 3.5 amps. The discharge efficiency could be up to 95%. The 6000mWh(4000mAh) high capacity Ideal for household appliances that require a D battery. Safety protection: Integrated into the built-in PCM, provides multiple safety: over-discharge protection, over-charge and short-circuit protection. Hixon offer:2 pieces rechargeable USB-C lithium D battery, USB-C cable.