Powerextra 7.2 Volt 2000mAh Battery Compatible with Dremel MultiPro Cordless Rotary Tool Models Dremel 7700-01 and Dremel 7700-02 Replace for Dremel 757-01(Do not fit Dremel 770 Type 1, 770T2, 7300) - - Amazon.com
Dremel MultiPro Cordless Model 770 Type 1 - Battery Pack Repair : 4 Steps (with Pictures) - Instructables
Cameron Sino Battery For Dremel 855-02 855-45 Fits Dremel 8000-01 8001-01 Power Tools Replacement Battery 2000mah 10.80v - Rechargeable Batteries - AliExpress
Turpow 12V 3500mAh Li Ion Battery for Dremel 8200 8220 Rotary Tool B812 02 8200 8220 8300 Oscillating Tool Replacement Battery|Replacement Batteries| - AliExpress
Old Dremel brought back to life by the power of 18650 : r/18650masterrace
Amazon.com: Rotary Tool Battery Replacement for Dremel 750-02 4.8V (1500mAh NIMH) : Tools & Home Improvement
Amazon.com: 2-Pack Replacement 755-01 4.8V Battery for Rotary Tool Battery (1500mAh, NiMH) - Compatible with 7300, 7300 PT, 7300 N 8, 755-01, Dremel 750-02 : Tools & Home Improvement
Dremel 760-01 3-Hour Battery Charger for Dremel Cordless Rotary Tool Models 7700 and 7300- Battery not Included- Dual Voltage 4.8-volt and 7.2-volt - - Amazon.com
Powerextra 7.2 Volt 2000mAh Battery Compatible with Dremel MultiPro Cordless Rotary Tool Models Dremel 7700-01 and Dremel 7700-02 Replace for Dremel 757-01(Do not fit Dremel 770 Type 1, 770T2, 7300) - - Amazon.com
Hacking together a better dremel battery! - YouTube