I have a 2011 skeeter ZX 200 with a minn Kota 3 bank on board charging system. I replaced both trolling motor batteries 2 years ago. When plugged in the number 1 and 3 batteries show full charge and light is green. However, the number 2 battery yellow light stays on. I have changed the in line fuse holder and checked the battery which shows 12.75 volts. Is it not charging right or could there be a malfunction with the light?
Any help would be greatly appreciated.

Try checking the same bank using a diff battery, if it is working with the new battery then you just have a bad cell in the battery. however if it still does the same then that bank on the charger is bad. The only thing you can do after that is to either get a new one or call MinnKota at 1-800-227-6433 and let them know the serial number of the charger to see if it can be replaced.

if you don't have a different battery laying around just change the leads from the charger and see if it does the same thing...

Thanks for the info.