Alkaline Door Lock Battery, 9v 2200mAh ~ BG-DL18 - Walmart.com
China Rechargeable 25.9V 18650 2200mAh/2400mAh/2600mAh/3500mAh 7s3p Li-ion/Lithium/Lithium Ion Battery Pack with BMS and Connector - China 3500mAh Battery Pack, Lithium Ion Battery 25.9V
Amazon.com: BatteryGuy Replacement for The Kaba Ilco 502250107 Alkaline Door Lock Battery - 9V 2200mAh : Electronics