Explosive tractor experience

[Jethro]

Okay...here's the skinny on the cause of the battery explosion:

I took the tractor to a local battery shop and they removed the old battery, sprayed foaming acid neutralizer over the affected areas and then washed everything off, installed a new battery and then checked my charging system...all at no additional charge (other than the battery)! Great service.

Anyway, it turns our I am getting 16+ volts to the battery when at full thottle. I ordered a new voltage regulator today. I should be up and running again Thursday afternoon.

Thanks for all of the feedback.

 

[scott_vt]

Very good description of what probably happened. The only other cause would have been an external spark at the connections that ignited the gases escaping an overly charging battery.

One final comment, never lean over a battery and install the cables, or clamp on a battery charger, or clamp on jumper cables. You don't want your face over a battery that explodes. I do not like batteries confined in small spaces with minimal airflow either. A battery needs good air circulation. I certainly don't like batteries installed in a box under the seat.

Uhh Ohh,
Both my old Farmalls are in enclosed battery boxes Although not under the seat, just under the GAS TANK

 

[turnkey4099]

I used my tractor for about 3 hours today and had just backed in onto the trailer when I heard and felt a very loud explosion from the tractor. Not a good feeling. I saw smoke, but the tractor was still purring along just fine. I initially thought I had blown a tire. As I got off of the tractor I realized the battery had exploded. It is underneath the seat on my tractor (Kubota B1550). I raised the seat and inspected it and the positive post for signs that it had arced, but found none. The electrical warning light had not been on. The tractor had been cranking fine. I had a new dynamo installed about 20 hous ago when the old one froze up. I have not had time to trouble shoot this yet, but I finally have a question:

<snip>

Reminds me of the year I retired from the military. Dad had just died and I was working around his place. Used his 40s something cornbinder pu to make a run to the dump. On the way back I heard a 'bang' but thought nothing of it other than it must have been loud to be heard over all the other noises. Stopped at courthouse to take care of business, came out and not even a 'click' on the starter. Pulled floor boards to find that the battery box had finally rotted out on the bottom droping the battery far enough to cut through the insulation and short out a cable. Nothing left but the top cap and all the plates dangling in the breeze.

Harry K

 

[RonMar]

i thought most of those type of incidents were caused by faulty vents. allowing the hydrogen to build up inside creating an impressive internal pressure.... (you know what happens next)

No, a clogged vent would build pressure till the filler caps popped off or loosened enough that the pressure was vented. Most caps these days ARE the vent for the battery anyway.

What usually happens is a spark ignites the hydrogen/air mixture either inside or outside the battery. If outside the battery the flame front follows the fuel in thru the vent to the gas inside. The very rapid combustion superheats the trapped air inside the case creating a tremendous overpressure(same as a engine combustion chamber) which exceeds the capacity of the vent and filler caps to exhaust. In the more extreme cases, the case usually fractures to vent the hot gas. These are usually minor and result in just the battery caps being popped off and a little acid splashed around.

An overcharge condition however can result in the most extreme cases of this as the excessive charge steadilly lowers the electrolyte level, increasing the internal volume of the battery where gas can build up, making the bang much bigger. Unless you have a volt meter or are checking the charge voltage or electrolyte levels regularly, you might not be aware it is even happening.

 

[Ford960]

Very good description of what probably happened. The only other cause would have been an external spark at the connections that ignited the gases escaping an overly charging battery.
One final comment, never lean over a battery and install the cables, or clamp on a battery charger, or clamp on jumper cables. You don't want your face over a battery that explodes. I do not like batteries confined in small spaces with minimal airflow either. A battery needs good air circulation. I certainly don't like batteries installed in a box under the seat.

I violated this good advise about 20 years ago while working on a 25' boat in the driveway. The batteries were in the bilges and I had charged them overnight. When I leaned down to hook up the cables again one of them exploded and a piece grazed my head just below my right ear. Acid hurts like he!! in an open wound and I jumped down and grabbed the hose to wash off all the acid. My next door neighbor came out and asked what happened that it sounded like a shot gun blast. I still have the scar to remind me not to do that again, still get the willies when I see a spark at a battery post.

Did see an 8D battery explode once in a Coast Guard 40' boat. The batteries were mounted in a vented well and the steel lid was the floor for the coxwain. That lid flew off and it's a good thing that the coxwain wasn't standing on it since it went about 30'. I got the job of cleaning this up and replacing both batteries as the other one received damage and leak most of it's electrolyte in the compartment. Did I mention that 8D's hold a lot of electrolyte and are pretty heavy too, especially when you're by yourself. Didn't help that I was a skinny little kid back then either.

As far as jumping vehicles, follow the recommendations that all newer vehilces have posted on stickers near the batteries. Always connect the ground last to a bracket away from the battery. Also to go a step further, if you feel the need to wiggle the clamps for a better connection, remove the ground that is clamped the the bracket first.

 

[flusher]

Reminds me of the year I retired from the military. Dad had just died and I was working around his place. Used his 40s something cornbinder pu to make a run to the dump. On the way back I heard a 'bang' but thought nothing of it other than it must have been loud to be heard over all the other noises. Stopped at courthouse to take care of business, came out and not even a 'click' on the starter. Pulled floor boards to find that the battery box had finally rotted out on the bottom droping the battery far enough to cut through the insulation and short out a cable. Nothing left but the top cap and all the plates dangling in the breeze.

Harry K

Similar thing happened to my 1961 VW bug in the 1960s. Battery under rear seat, leakage, corroded metal pan/floor panel finally gives out. Battery fell out under the car while doing about 30 mph on city street. Fixed that with an steel patch and a new battery. Didn't realize the corrosion had gone so far.

 

[smitesmash]

some of the new "maintenance free" batteries do not have vents. They are sealed and expect to be able to maintain quite a bit of pressure.

how do I know this...

when batteries discharge, they produce hydrogen, and when they charge, they produce oxygen. (or vice versa, college was a long time ago). Both of which they get from water, which needs to be replenished

the day I was picking up my new motorcycle, another person was also getting their new bike. on their bike, the starter solenoid got stuck and the starter motor would not disengage. After several frentic minutes, someone got one of the main electrical wires cut. I saw the battery several minutes later, it looked inflated. Partially due no doubt to the additional heat, but also due to the large internal pressure it was experiencing.