I have brought several batteries back to life with a manual charger.
Float chargers will only charge if there is some charge in them, but hook up a manual set on 10 amp for a hr, then switch to 2 amp for a day then just set a float charger on it and let it finish and gtg.

I only get agm or better.
Odyssey makes some great batteries.
Got some lithium cells to play around with and try.