All I can say is that I've got 2-15 amp Dual Pro pro series chargers, to charge 4 batteries, one of which I've had for 14 years and is still going. One benefit is that if they fail then they are repairable. I've got 2 friends who bought the Minn Kota 3 bank chargers and eventually, less than 3 years, one of the banks failed. But they are not repairable so you have to replace the whole unit. I know the Dual Pro pro series' aren't cheap but could very well be the cheapest in the long run. I found one of mine on Ebay for about half the price of a new one.