4X AAA Mirco USB Rechargeable Battery 600mAh 1.5V Toys Remote Lithium Polymer

Rated capacity: 600mAh. Rated input: one Micro USB input /5V. Shell material: high quality fire ABS plastic shell + copper electrode. No longer to worry about the endurance of the batteries, this battery will provide ultra strong Power for your devices to performance well and operate longer.

eBay