Amazon.com: Tenergy 9V NiMH Battery, High Capacity 250mAh Rechargeable 9 Volt Batteries for Smoke Detector/Alarms, TENS Unit, Metal Detector, and More (4 Pack) : Automotive
Amazon.com: Tenergy TN141 Smart Charger for NiMH 9V Rechargeable Batteries, 9V Cells Battery Charger, 9 Volt NiMH Batteries Charger, 2 Slot 9V Fast Charger for Smoke Detector : Electronics