The time needed to rejuvenate the battery depends on the state of the battery a deeply sulfated battery may take weeks... .... If it can be repaired at all.

Not high voltage ... But higher than 15 volts less than 20 - pulsating spikes.

Never constant high voltage and you say you know? Pulses kill a battery ... are you kidding me?

Can you back it up with facts.

Several companies offer anti-sulfation devices that apply pulses to the battery terminals to prevent and reverse sulfation. Such technologies tend to lower sulfation on a healthy battery but they cannot effectively reverse the condition once present. Manufacturers offering these devices take the “one size fits all” approach and the method is unscientific. A random service of pulsing or blindly applying an overcharge can harm the battery in causing an overcharge condition and promoting grid corrosion.

Found this statement by many............



Without the proper pulse for that 1 battery it can harm it,freq based desulfation takes that harm out.