Upgraded Philips Sonicare 3.7V 800mAh Toothbrush Battery with 35% more run time
Capacity: 800mAh. Internal resistance: within 50mΩ. AA 14500 3.7v 680mAh Li-ion Battery with Solder Tabs. Battery model: US14500VR2. Material: (Li-ion Lithium Ion Battery). 1 Li ion battery With Welding.