Ted writes:

<<
To top off a battery and desulfate it may
take days or even weeks depending on the condition of the battery.
>>

When a lead acid battery is discharged, Lead (Pb) in the negative electrode and Lead dioxide (PbO2) in the positive electrode react with the Sulfuric acid (H2SO4) producing Lead SULFATE in both electrodes and water (H2O). Charging reverses this reaction.

Therefore there is another term for "desulfating", it is called "Charging". ALL battery chargers, when used on lead acid batteries, by definition, "desulfate" the batteries they are charging.

Now go have a cool glass of dihydrogenmonoxide and relax.

Regards
Brent Regan