I'm charging a battery bank with solar but when the long cloudy days come I need to top them up with the grid. I hate using my old heavy 10amp car battery charger.(At best 55% eff.) You can make toast on that when the batteries are low and it's pushing high current. So I found 3 switching adaptor power supplies used for computer printers. The rating label says 18v@2.25a. I loaded down to 13v and got 5.3a. I connect the 3 supplies together in parrellel and get 17A into the battery bank. I drilled a few holes in the case and put on a computer fan. Works GREAT. Input 120vac@2.1a , output 13v@17a or 252w in ,221w out = 87% efficient. My Morningstar charge regulator holds the volts to 14.3v for my sealed batteries.
