Amazon.com: PKCELL ICR10440 Lithium Ion Rechargeable Battery 3.7V 350mAh with USB Charger (2pc Button top +Charger)(They are not AA Size Battery) : Health & Household
3.7V Lithium Polymer Battery Cell Manufacturers and Suppliers based in China
Amazon.com: Amityke 3.7 Volt Rechargeable Battery 3500mAh Battery 2Pack Large Capacity Batteries for Headlamp, LED Flashlight, etc : Health & Household