Xtreme Marine, pulse charging
I've been testing this PulseTech Xtreme Marine 12v “five-stage maintenance” charger for a month or so, and am impressed. What with Annie G's two batteries—one for the electric trolling motor, another for backup and electronics—plus some old batteries I’m trying to keep alive until someone buys Ralph, I’ve had plenty of material to work with. I really like how the Xtreme first tests a battery and then tells me with simple to understand LEDs what it’s up to as it goes through its multi step process. And while it’s impossible for me to really see the claimed desulphation process in action, the batteries certainly seemed very well charged. (Plus PulseTech has some scientific studies, using x-ray, that seem to back its claims). I was even able to use it to bring back a dead flat battery which someone around here had allowed to go completely dry; I did have to start the charge with a conventional “dumb” charger but the Xtreme (which first found it “bad”) took it from there and seemed to really perk it up. Charging a really low battery does take time, though, as the Xtreme only puts out 2.5 amps in bulk mode (5 amps claimed effective); hence the “maintenance” caveat. But you can just leave the charger attached to a battery indefinitely as it will stop charging and go into float/pulse mode when a battery is topped off. There are other pulse chargers and battery conditioners out there (a good explanation of charging, pulsing, and desulphation here), but Xtreme seems like a winner.