here is the battery pack which I use to run my Chargemaster, also recharges your computer, cell phone or ipad.
https://www.amazon.com/RAVPower-23000mAh-Portable-External-Smartphones/dp/B00HFMUBYG/ref=sr_1_3?ie=UTF8&qid=1490206250&sr=8-3&keywords=9v+output+battery+pack