Synergy Digital Power Tool Battery, Works with Dremel 8300 Power Tool, (Li-Ion, 10.8V, 1500 mAh) Ultra High Capacity, Compatible with Dremel B812-01 Battery - Walmart.com
3500mAh Battery for Dremel B812-02 8200 8220 8300 B812-01 12 Volt Rotary Tools | eBay