Phone reboots before fully rebooting after logic board transplant

Hello all, I recently had to transplant my Logic board from my iPhone 5C (blue) into my friends water damaged iphone 5C (green), as the blue one had suffered from a fall so bad it had dented the steel frame through the plastic, and into a position where the screen could not be re-attached fully. I successfully transplanted the logic board from the blue phone to the green phone.... but when plugged in it shows the battery empty indicator for a few seconds, then the apple logo as it tries to boot, and then shuts down and starts doing the same thing in an endless loop.

My question is, did I not put the logic board in correctly? Or perhaps is the battery or charging connector damaged from the water damage (it is all fully dried out by now of course). My feeling is on the battery, but I am unsure of if I screwed something up with the grounding screws and parts at the top of the phone when doing the transplant... although I am fairly certain I did it correctly.

If it is the battery, I removed the battery from my blue phone although it does not look good (it was swollen after the initial drop) and I feel I may have worsened it when removing it. Should I still try using that battery?

Thank you for your time and help!