The APR18650M1 is a LiFePO4 (Lithium Iron Phosphate) battery cell manufactured by A123 Systems, Inc. It is a cylindrical battery with a diameter of 18mm and a length of 65mm. The cell has a nominal voltage of 3.3V and a capacity of 1Ah. It is a high-power, high-drain battery with a maximum continuous discharge rate of 10C (10A). The cell has a charge time of approximately 2 hours, and has a 10 year lifespan. The APR18650M1 is commonly used in a variety of applications such as electric vehicles, medical equipment, power tools, and renewable energy systems.