I've got two Deltrans. A jr. model on my dump trailer and a bigger version on a backhoe. A buddy that had a bunch of cars and bikes suggested Deltran over some of the other brands he had tried. He bought them in lots of 5 or 6 on feebay at a real good price. Someone mentioned them causing batteries to blow up. That was probably a trickle charger, not a tender/maintainer.