>>283033521
https://github.com/ykeara/hardware_vivetrackerbattery
Honestly, I have the trackstrap with batteries thing, and it's not that great. It's nice that it's integrated, but you have to unplug the battery anyway to avoid the tracker getting into this weird frozen state where it won't turn on unless you unplug it for a couple minutes.
>>283033671
Is right, just get some cheap 2Ah power banks, short usb micro cords and wire them yourself.