Hello, what model of battery can I use for replacement?

Wondering the same. I have a 1000mAh battery here coming from a small vape, but looking at the original battery it seems to have some battery protection circuitry inside the battery wrap, my new battery seems to have the leads soldered directly to the cells.

I'm wondering now if the TinyTV2 has proper charge protection built in already and if it would be safe to use this alternative battery together with a custom slightly larger case