who makes the best one in your opinion and why? are they the best way to deal with keeping the trolling motor batteries up? i run a 12-24 volt system and have a third battery as a reserve in case one goes weak during a trip. try to charge each night but having 2 or 3 chargers is a pain..as i see it i could plug in one cord and get the 3 batteries charged during a night. any advice is appreciated.