Sulphated Battery

[ALANSD]

isn't there a way to force charge a sulfated battery back to life? One of my house batteries will only stay up to 9v or so, it is sealed so i can't check fluids. A full charge will hold for a day or two, then it stays at 9 for a long time. Is it ready for the trash heap? A delco marine/rv type.

[74Argosy24MH]

If it is only 9v it is shot. Change both of them. If you only do one the new one will discharge into the older one and drag it down quickly.

John