exploded flooded lead acid battery

jimbob01

Any ideas why?

battery was outside on charge at the time...110ah 12v battery with around about a 10a charger connected at the time... some one was sanding some paint near to it at the time...no reported sparks
the entire top half of the battery is missing...1yr old battery.

jcheil

Re: exploded flooded lead acid battery

Where was the charger (physically) in relation to the battery?

There are plenty of "sparks" in the charger that could have ignited the hydrogen from the battery; especially if the charger was sitting above (or worse - on) the battery.

And unless they were sanding by hand, or with an air sander (and the compressor was inside), the electric motor from the sander causes sparks also.

jimbob01

Re: exploded flooded lead acid battery

the charger was inside about 4ft away from the battery ...
the guy was sanding away from the battery with 240v da sander with his back to the battery...

NorthGuy

Re: exploded flooded lead acid battery

I've heard that if water level is low, the exposed plates may warp and spark, causing the hydrogen-oxigen mix to explode.

niel

Re: exploded flooded lead acid battery

it could've been one of the battery clips slipped its grip and sparked and imo is the safest bet as to what happened as the spark would've been right there at the battery.

waynefromnscanada

Re: exploded flooded lead acid battery

Well, the only sparks in or from the charger would be if it's DC output breaker was opening and closing due to overload or defect. Any other internal sparks would be the result of defects, not normal operation. As Niel said, one of the clips COULD have slipped. Considering the distance from the sander, it would be virtualy impossible for the motor to have caused the ignition. If it had been a high speed grinder showering the battery with white hot metal sparks, well that would most definitely be a whole different story.
Most plausible cause in this case is an internal battery fault. Either as was mentioned, a spark causing short between plates, or an internal inter-cell connector coming loose or fracturing, resulting in a spark.
I once discovered the battery had ruptured in a car I once owned. Part of the battery top was missing, the rest was buckled and bulged, and all the caps were missing. Strangely the battery still started the engine OK and I had no reason to suspect any battery problem - - - until I happened to look at it. Had no idea how long it had been that way. Did a lot of thinking at the time, trying to remember if I had ever heard a bang etc, but ended up with no clear answer. Likewise, never did find the cause of the explosion. In that case, there was no evidence of acid having been splashed about either. I suspect, like your batteries demise - - - - it was just one of those things with no clear explanation.

northerner

Re: exploded flooded lead acid battery

NorthGuy wrote: »

I've heard that if water level is low, the exposed plates may warp and spark, causing the hydrogen-oxigen mix to explode.

That sounds like a plausible cause. Particularly if the battery is being charged and then discharged, I would tend to think would generate plenty of internal heat which can cause metal to expand. If there was even a slight internal separation or touching of a warped plate, that would explain a potential arcing causing the hydrogen / oxygen gas to ignite inside the battery.

gww1

Re: exploded flooded lead acid battery

In augest I bought some scrap batteries so I could test my inverter. I charged them pretty hard. Everything was working well till I run a 10 amp circular saw. battery exploded when I pulled the trigger. The whole top was gone and a big puddle of acid. It was not low on water. My guess is crap in the bottom of the battery getting agitated from the large draw of the saw causing the plates to short.
Cheers
gww

BB.

Re: exploded flooded lead acid battery

Corrosion can also lessen the ability of internal grids/conductors to carry current in old batteries... A heavy current draw could "fuse" a weak current path and cause an arc/explosion too.

-Bill

Cariboocoot

Re: exploded flooded lead acid battery

Sealed battery or open?

The sealed ones will sometimes blow when charged rapidly, especially if the valve won't open. Pressure builds up inside and the top comes off.

Not likely spark ignited hydrogen if its in the open as there's no place to build up an explosive mixture (unlike in a battery compartment or under a vehicle hood).

NorthGuy

Re: exploded flooded lead acid battery

Cariboocoot wrote: »

Not likely spark ignited hydrogen if its in the open as there's no place to build up an explosive mixture (unlike in a battery compartment or under a vehicle hood).

When water level gets low, there could be enough space to build up the mix. Theoretically, that is

jimbob01

Re: exploded flooded lead acid battery

well thanks for all the response...guess im never going to actually really know the cause...i suspect battery failure due to the plates warping could be high on the list...the battery was not of the sealed type...thanks folks...jim