3.7V 2000mAh Rechargeable Batteries for Large Capacity Auxiliary Battery | eBay
Smatree Xbox One Battery Pack 2 x 2000mAh Rechargeable Battery for Xbox One/Xbox One S/Xbox One X/Xbox One Elite Wireless Controller : Amazon.com.au: Electronics
2000mAh AA Size NiMH Rechargable Batteries (4 Pack)