I have a 3 bank on board charger and keep it plugged in 24/7. All 3 banks had green lights on. I check the water levels monthly and at the last check the water levels were up to the split ring or slightly below on all 3 batteries. Today, the 2 TM batteries are still ok but the starting battery (6 months old) is bone dry. I have added a gal. of distilled water and still only barely cover the plates (how much can a size 29 battery hold?) I also notice the battery sides are bulging. Question: Is the battery toast and why all of a sudden is it the only one to go dry? Do I have a problem with the charger bank for that battery? If the charger is working properly wouldn't they all still be ok? Should I take the battery in at this point for an exchange if they will honor the warranty? Any advice is appreciated. Thanks.

Charlie

I'd be looking for a new cranking battery. I have never seen a bone dry one that made a good recovery. I'd also back off on the charger. I have a Dual Pro and was going to leave it on for 2 months while on an extended trip. I called Dual Pro and they said don't leave it on that long so I charge up then top off every week or the night before a trip.

I would say its the battery. Once they start bulging out, they are toast. I leave my onboard charger hooked to mine. The TM batteries get used 2-3 times a month too. I wouldnt think it would be the charger.

Thanks for your response. Went with a new battery. I agree that I think it is not the charger but will be checking the output when the green lights are on. I have had an on board charger for years and never had a problem with leaving them hooked up 24/7 (at least with the first one it was a 2 bank). I now have a Minn Kota 3 bank and this is the first time I have ever had an issue.

Charlie