Type-C Micro USB D 1.5V Lithium Li-ion Battery and Rechargeable D Batteries - China D 5600wh Rechargeable Battery, Household 1.5V Type C USB | Made-in-China.com
D - Size - Batteries
High capacity D-size rechargeable battery 10,000mAh – EBLOfficial
Using a D-Size Battery String for a UPS Energy Source | Math Encounters Blog