Works as in it recharges a battery from some unknown percentage to some unknown percentage, or works as in 'it magically restored the battery I know nothing about to the point it can start my car?'
The forced 15.7v option at 3 amps does give it one up on most automatic chargers.
Does 25 amps meet your battery manufacturer's 'recommended' initial amps?
Trojan recommends 10 to 13% for their batteries, or 10 to 13 amps for a 100 AH capacity battery.
How long do you have to plug into the grid and perform a recharge?