Amazon.com: LP 9V Rechargeable Battery Pack, 2-Pack 600mAh Li-ion 9 Volt USB Battery with Micro USB Charging Port for Alarms, Wireless Microphones, Smoke Detectors, Toys, Flashlights, Guitar, Keyboard & More : Health
EBL 9V Rechargeable Batteries NiMH 280mAh 9 Volt Battery for Smoke Alarm Detector, 4-Packs - Walmart.com