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Tnbigdaddy.
I had one of the three trolling motor batteries blow up in the boat on the water this weekend and am starting to research the cause and future prevention and would be grateful for input. 2010 Puma FTD – Merc 250 Pro XS4 Battery Set Up – 1 Cranking (Sears PM1) – 3 trolling (US Battery Group 31 Lead Acid) approximately 3 years old.I check water levels every 4-6 weeks, and top off with distilled water when needed.Stealth 1 Charging System – AC charger and on the water charging.The battery that blew was the negative to the trolling motor – the last battery in the series. Boat was on Stealth 1 charger 3-4 days prior to the tournament. The 3 trolling motor batteries had some parasitic draw happening so I had them on the charger until tournament morning to make sure they were topped off. I don’t leave the batteries connected to the charger constantly, typically they get plugged in for a day or two after I return from fishing, and then get plugged in for a day or two before the trip. Launched the boat, cranked the motor, backed it off the trailer, then dropped the trolling motor, noticed the trolling motor was very lacking in power, about the time I was thinking “that’s odd, I know the batteries are charged” BOOM! It shook the whole boat. At first I thought the trolling motor blew up, pulled it and it was fine, then went to the back deck, opened the lid, and proceeded to catch a face full of sulfuric acid. Removed the extra life jacket and throw cushion, determined there wasn’t a fire (Thank God), and let it vent. Put the boat back on the trailer, removed the exploded case battery, soaked up all the acid I could with paper towels, and then changed it back to a 3 battery set up for the tournament. When I got home the entire bilge got a baking soda and water bath, twice. Most of what I found on batteries blowing up is when they are on the charger. Mine happened on the water. I guess there was some sort of short inside the battery that caused it. Should I contact the battery manufacturer? The charger manufacturer? Should I be concerned about hull damage from the shock wave? Do the gas tanks need to be removed to inspect for damage/cracks? Any specific areas or items I need to look at more closely than others? Is there anything I am overlooking? I unplug the trolling motor plug in when I come off the water for safety. Could the battery that failed be causing the parasitic draw on the 3 trolling motor batteries? If not then could the parasitic draw be caused by breakers aging? Although AGM batteries can explode, the little research I have done seems to show that it happens to lead acid batteries more frequently. Should I consider using the AGM’s instead, or chalk this up to a freak accident and stay with the less expensive and lighter weight lead acid?
Hydrogen gas and obviously inside a battery it can cause an issue. Hydrogen can be very volatile and we have seen batteries explode for decades. Often it seems some form of current or action is in place to cause it, though seldom (less frequently) we we them fail when static. We wont comment on what causes it. There are a couple of really solid battery company staffers that could have an opinion on this topic, and they frequent this site.BCB
Not going to say what caused it in youre instance, but can tell you the basics as to why. First off though, the negative battery is the first battery, not the last in the sequence. Not that it makes a difference, just a FYI moment. DC current travels from negative to positive so the trolling motor is “pulling” from the negative battery 1 and returns to the positive battery 3 in the 36V system.In a series circuit, there is not a battery that becomes a “load” to draw the others down. All are pulled equally. If the trolling motor is unplugged, then it cant be the load/draw either so this leaves the charger assuming nothing else is connected to the battery. If the Stealth 1 is the only charger being used, then it may be monitoring the batteries and causing a “load” or draw.Back to the battery exploding. When the battery charges, it produces Hydrogen gas (excessive gassing will give off a rotten egg smell) — yes we all know that and know how volatile Hydrogen gas is. When you stepped on the button to run the trolling motor, it completed a circuit through the batteries, something internally arcd, and exploded the gas. This is the reason for making sure the batteries are charged in a well ventilated area in order to disperse the hydrogen gas as a bilge not allowed to vent can build this up inside and a loose battery connection can arc and set if off.John
Had my starting battery blow up on me years ago on my old 85 Phelix I heard a boom and the motor stopped, thought I blew the motor until I opened the back hatch, and I hooked up one of the trolling motor batteries to the motor to get home. That battery was only about a month old when it blew, and the A/C Delco distributor replaced it, and we never found out what caused it for certain.
Had a golf cart battery explode one time. Batteries seemed to be in good shape, took charge fine, had golf cart parked, hopped on, hit “gas” pedal and boom battery exploded right under the seat. Have no idea why it blew. Assumed something broke loose internally. Not much help for you I know but does happen.
that must have been a scary moment. I have been hearing an arcing noise when I plug my batteries in after I get home. it only does it for a short time and is intermittent while doing it. I have been wearing safety glasses when my head is in the bilge area for this very reason.when it is made by the hands of men, it will fail in the hands of men.glad you were ok and the boat didnt burn up
Thanks everyone for the replies. I spent some time on the phone with Danny Roberts @ Stealth1, verifying that the charger is doing what its supposed to do – output, voltage, and cycling. The charger is doing what it is supposed to do with output and is not overcharging or charging when its not supposed to be. I can only assume that the battery got an internal short igniting the hydrogen gas and causing the case to rupture. Danny will teach you more than you ever wanted to know about batteries, charging, and voltage…….. He is definitely a stand up business owner who will talk with you after hours or on the weekends. My boat is 8 years old and the warranty is up but he still took the time to speak with me after hours while I was at the boat with a voltmeter in hand to prove out everything was working correctly. Top notch customer service!
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