These chargers are totally waterproof and shut off completely after charge. No trickle charge. Return to charge maintenance mode. No installation restrictions. Dual Pro: 15 amps each. Weighs 15 lbs. 12V/24V. 6” x 6 1/2” x 11 1/2”Three Bank Pro: 15 amps each. Weighs 22 lbs. 12V/24V/36V. 6” x 6 1/2” x 14 1/2