How to fix sidewall scratch

There's no really going back to normal but you can squirt a lil epoxy on it to keep the water out. I'd just ski them topsheets get nicked by the edges all the time.

If you carefully apply a little dab of West Systems G Flex Epoxy and clamp down that lifted bit of topsheet, allow to fully cure then sand down with increasingly fine sandpaper grades until it is almost polished and it probably won't be noticeable at all.

if put a second battery beside the existing one it should seal itself up