Dual Pro 15 Amp/Bank Professional Series 2 Bank Onboard Battery Charger - Perfect for Marine, RV, and Off-Grid Power Systems

Dual Pro makes the best chargers. I have a whole pile of broken chargers of other brands, this seems to be the brand that lasts and always charges batteries consistently.About the only limitation is also one of its strengths -- it's transformer based so it has the best electrical insulation you can get (think of lightning strikes etc), but it also means it needs a pretty good supply. It doesn't work well off inverters and it doesn't work well if the voltage is more than about 10% higher or lower than the nominal 120V. A high voltage causes it to overheat and shut down, a low voltage causes it to charge at a low rate.Other than that I have nothing bad to say about these.The major competing brand is NoCo , and I have had a few of them. They are lighter but I have had problems with their charging algorithm, which is claimed to be "wicked smart" but isn't -- once they go to the float stage they shut off completely and if there is a drain on the battery it will drain even though the charger is still connected and says the battery is full. The Dual Pros are smarter and actually keep the battery up.