Battery Explosion

[BelleAurore]

Recently I had one of my thruster batteries explode. Battery is a maintenance free only 3 years old. Battery was one of two 12 volt batteries wired in series. Batteries were purchased at the same time and installed together. Charger is a 24 volt Mastervolt that was new when batteries were installed. The explosion happened after I cranked the engines getting ready to leave the slip and tested the thruster with a short engage. The battery cables were tight and there is no arc indication on the posts.

This seems to be an internal event as the pictures show. It’s been suggested the cause is overheating caused by a defective charger. I’m not defending the charger, but if that is the case why did it take me energizing the thruster circuit to cause the battery to blow.

I’m just looking for ideas that would cause this.

 

[BruceK]

2 similarities to Kit L`s explosion in another thread. Sealed type. And Delkor brand. I suppose a capped unsealed batt would blow a cap before exploding.
If the sealed type can vent off all the acid, could that cause it?
Unfortunately/unhelpfully, more questions and observations than answers, but it may help.

 

[High Wire]

Make sure you go to town with baking soda/water mix, on all of the acid splattered everywhere around the blown battery.

I had a battery that would get very hot under the plastic about an inch away from the positive terminal. Suspect bad internal connection.

 

[alfamike]

Battery blows up

Fact - there is nothing explosive in the water & sulpheric acid mix inside the battery that makes up the electrolyte. What explodes is the hydrogen & oxygen gas trapped inside the battery & made from over charging the battery & then when electrolyte gets low allowing room for it to gather.

This can happen to any Lead Acid battery, even AGM batteries, which are often called sealed, but that is a misnomer, they do vent off gasses, typically with a special vent valve & often when charged at to high a voltage or if charged to long, or over charged & have loss of fluid in the cells.

only one thing in a battery to explode - Hydrogen & Oxygen gas & add in a spark from an exposed plate some where inside the battery due to over charging & loss of distilled water giving it room for the explosive atmosphere to hold the gasses & then the plate with a small growth called a branch which is a metal transfer similar to electro-plating process that can grow & then shorting & causing a spark -- then boom.

That is why we put our batteries in a battery box, just in case. -- stay safe my friends.

Alfa Mike

 

[tiltrider1]

Fact - there is nothing explosive in the water & sulpheric acid mix inside the battery that makes up the electrolyte. What explodes is the hydrogen & oxygen gas trapped inside the battery & made from over charging the battery & then when electrolyte gets low allowing room for it to gather.

This can happen to any Lead Acid battery, even AGM batteries, which are often called sealed, but that is a misnomer, they do vent off gasses, typically with a special vent valve & often when charged at to high a voltage or if charged to long, or over charged & have loss of fluid in the cells.

only one thing in a battery to explode - Hydrogen & Oxygen gas & add in a spark from an exposed plate some where inside the battery due to over charging & loss of distilled water giving it room for the explosive atmosphere to hold the gasses & then the plate with a small growth called a branch which is a metal transfer similar to electro-plating process that can grow & then shorting & causing a spark -- then boom.

That is why we put our batteries in a battery box, just in case. -- stay safe my friends.

Alfa Mike

This says it pretty well. The only thing I can add is there is no such thing as a maintenance free lead acid battery. Batteries with condensation caps built into them will make such claims as maintenance free for the life of the battery then in the fine print they will retract the statement with under normal circumstances as defined by the battery maker and for a life of 4 years. Over charging is usually one of their first exceptions.

 

[alfamike]

Battery issues for flooded lead Acid batteries

tiltrider1 - your 100% correct.

Batteries are often in locations on the boat that are hard to get to & so the crew does not check the battery water on a regular basis & top off the cells with distilled water as needed. That is a big mistake.

This leads to the electrolyte levels being allowed to get low & that means more room for the gases to gather in larger quantities - the more gasses, the bigger the BOOM. All due to the owner or crew not keeping tabs on this & it becomes a self induced result from lack of maintenance & the "perfect storm set up" of the issue we are discussing here.

Don't let this happen to you my TF friends. Top off your batteries regularly. Use distilled water only.

Alfa Mike

 

[Duvie]

When I was younger I had a dirt bike battery blow up under the seat when I was driving it! Upon inspection I noted that the breather tube for the battery was plugged up with mud. I believe the explosion in that case was just pressure build up and not due to ignition.