Not sure how the Poke models are assembled. However, if it is anything like the Note models, then it should be very easy to open it up and replace the battery. I did so myself on my Note Pro and I'm not very handy at such things.
It looks like you can get a replacement battery with a connector attached on Aliexpress:
https://www.aliexpress.com/item/1005...0260dc3494f5-2
As a reference, you may want to check out this thread about replacing the battery in the Note model:
https://www.mobileread.com/forums/sh...d.php?t=339908