The iPhone “iPhone” could not be updated. An unknown error occurred (2015).

I have an old iPhone 5s that is stuck in Recovery Mode. Its pretty badly broken and I'm trying to get the old Photos and Videos off of it. My Mac says Software: iPhone Recovery Mode. Then I go through the process of trying to update it through my MacBook. The prompt says: If your iPhone can’t be updated, you will need to restore it to its factory settings. Your Mac will update your iPhone to iOS 12.5 and will verify the update with Apple. It never succeeds, it always fails with the 2015 error. I click update and wait. The battery always shows up red in the beginning, so I have a feeling the battery is unable to charge and I don't know if that could be the issue.