2 round cells, likely in series, 1.2-1.4 v/cell, that's 2.4 - 3.0 v total. A 1S lipo might be a good match (3.7-4.0v). Cheaper & smaller yet. The motor will likely have some headroom tolerance.
Chargers for this kind of low=S Lipo stuff is no brainer, often they will run off a USB or wall wart. Link is much fancier than you need but just as an example. 1S has does not have separate balancing plug so charging is easy. Plug in & press go. I use 1S in my DLG
Chargers for this kind of low=S Lipo stuff is no brainer, often they will run off a USB or wall wart. Link is much fancier than you need but just as an example. 1S has does not have separate balancing plug so charging is easy. Plug in & press go. I use 1S in my DLG