From the description- They are junk.
I Tried to revive a few last year that were fresh off a system- and there was no hope for them. Which was too bad as I could have had 200 of them for scrap value.
So don't even pay scrap value for them, they should pay you to remove them- your gas or diesel has to be worth something.
Their design does not lend them to desulphating.
They are just considered to be "Primary cells/batteries" and that is all.
30 KiloWatt Brats anyone?