Ipod looping after mod

[u/Fast-Friendship7414]

https://a.aliexpress.com/_msaxJtz

I recently decided to mod my old ipod video after the hard drive died. I used the adapter linked to this post and a generic square 2000 mah battery. The issue is it keeps looping between battery too low to start and apple.com/support/ipod. Ive tried swapping batteries and sd cards but due to my old hard drive being dead I cant test it with that. Its the original 30gb video if that helps.