Amazon.com: Tenergy 9V Battery Rechargeable 250mAh 4 Pack NiMH Square Battery with 2 Bay 9V Battery Charger for Smoke Alarm/Detector : Electronics
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