I get the longest life out of my boards without running converters.
When I run converters I have good AGM batteries as a buffer. I know there is a debate about whether or not you need them, so I figured I would just throw that in there since my authorized Minn Kota guy is convinced the converters are what causes board failure and feels very strongly that if you don't have the batteries you will go through them even faster. I also know if you try to run your onboard charger while running your trolling motor you will have a higher frequency of failure.
When I ran the IOTA 36V converter I replaced boards very frequently, just guessing about every 20 hours. What I think was happening was the IOTA didn't put out enough amps to keep the batteries full (I can't remember the amperage on the model I had and I will be the first to admit I don't know **** about electricity so this post probably sounds pretty ignorant) and when I would run long enough to wear down the batteries completely it would wreck the board.
Since I switched to Powermax I have been getting I'm guessing an average of about 70 hours out of each board. I just wrecked my first one for the year about 2 weeks ago because I have been finding fish in deep enough water out of the thick weeds so it's been pretty easy on it.
