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 : Electronics
PP3 9V Battery Snap Clip Connector Cable Lead 150mm 9 Volt Holder Various Size | eBay