Zebra Extended-life battery pack offers twice the battery capacity
of the standard battery pack and is the perfect solution for higher
duty-cycle applications. Compatible with the following Zebra mobile printers: ZQ610, ZQ620, ZQ510, ZQ511, ZQ520, ZQ521.
BATTERY CAPACITY: 6500 mAh.
Detailed Specs
Zebra Mobile Printer Accessory Guide.pdf
https://www.thermalprintersupplies.com/content/product_downloads/zebra/Zebra Mobile Printer Accessory Guide.pdf