That's more of a maintainer You won't get a badly sulfated battery to desolve the chrystals unless you use some more energy . The best recovery device I've found is a fused ac line and a large rectifier or you can use an inverter above the 400watt range a cap in series at 20 to 25 uf per amp (running capacitor ). Start at low amperage and see if you can get the battery to go to 15 volts and cool to 12.6 to 12.8 and load test .May take even a good battery to or three 45 min pulseings . An inverter is good because you don't need an isolation transformer .Fuse inline of coarse and remember a REAL SHOCK HAZARD.
