Does such a thing exist?

Most of the XPS chargers from BPS have pretty lousy reviews. Same for the Dualpro chargers from Academy.

I run two batteries, but only one needs regular charging. I fish often enough that the starting battery seems to stay charged from the outboard. I have been using a Dewalt 4 amp charger/maintainer, but it seems to be dead after 6 months. Since then I've just been using a Schumaker trickle charger, but it takes forever to charge a group 29 battery at only 750ma.