3,2,1, boom!!

[Jeremy]

Why do batteries go boom??

Everyone seems to accept that it happens, but I have not seen an explaination of why it happens, and what, if anything, you can do to prevent it from happening. Fortunately it is something I have never experienced, but I am wondering if I should always be using gloves and goggles etc when handling batteries.

I like the idea of having the battery isolation switches in a standard location, so everyone can access them - mine are pretty well hidden and certainly not accessible from outside the bus. In the UK all buses (not coaches) are fitted with a big red 'engine stop' switch on the rear, so anyone can switch the engine off in an accident or emergency. I once heard of a bus that was stolen by joyriders being stopped by a chasing police car who managed to hit the switch with a broom handle.

Jeremy

[belfert]

Buswarrior, there is an exception to the rule to disconnect the negative first. If there is an operating inverter, diconnecting the negative first can ruin it. In this case, the POSITIVE must be disconnected first.

I have a 225 amp circuit breaker/disconnect switch on the line to my inverter.  It came from a large UPsS.

It disconnects positive and negative at the same time.  Will this hurt the inverter?

Brian Elfert

[Stan]

A mechanical circuit breaker will not break both poles at the same time; close maybe but milliseconds difference could be fatal to your inverter.  Do what your inverter manual calls for. At least you have an argument with the manufacturer if you have a failure.

[Lee Bradley]

Why do batteries go boom??

Everyone seems to accept that it happens, but I have not seen an explaination of why it happens, and what, if anything, you can do to prevent it from happening. Fortunately it is something I have never experienced, but I am wondering if I should always be using gloves and goggles etc when handling batteries.

I like the idea of having the battery isolation switches in a standard location, so everyone can access them - mine are pretty well hidden and certainly not accessible from outside the bus. In the UK all buses (not coaches) are fitted with a big red 'engine stop' switch on the rear, so anyone can switch the engine off in an accident or emergency. I once heard of a bus that was stolen by joyriders being stopped by a chasing police car who managed to hit the switch with a broom handle.

Jeremy

During operations, lead/acid batteries off-gas hydrogen gas an extremely flammable gas. That gas collects in the voids, in the battery, above the electrolyte where a spark or even high temperature can ignite it. I was working in a maintenance shop some years ago when I had to retrieve a pick-up truck with a dead battery. I jumped the dead battery from the battery of another vehicle, positive lead to the positive post and then negative lead to a ground point on the engine NOT the battery, I let the battery charge for several minutes from the running vehicle and then tried starting the pick-up truck. When I engaged the starter, I was greeted with a very loud bang. The dead battery was now very dead as the cover and one post was lying on top of the engine and a fine mist of electrolyte was in the air. Apparently there was a bad intern connection in the battery that sparked or got extremely hot when I engaged the starter and ignited the hydrogen gas generated during the time I let the battery charge. Fortunately I was inside the vehicle and my helper was in the other one. Granted a very rare occurrence to have a battery explode that way but they are not to be trusted.   

[Kwajdiver]

I have a disconnect on my coach batteries.  Sounds like I need one on the house batteries also.

Any special type that everyone uses.

Bill

[FloridaCliff]

Devin,

Glad your OK!

This is just another reason to use AGM's.

Though not fool proof, they almost entirely eliminate this gassing problem.

The extra upfront cost is easily overcome by any damage that a lead acid may cause.

Just my .02, I deal with a lot of commercial UPS's that have giant battery banks. (All AGM)

All of them have disconnects and fuses on the output.

Size your fuse to just above your maximum demand, but remember that your generator(if connected to house bank) may try to

charge at a higher amperage.

This happened on mine and I had to adjust the fuse to accomadate this.

It would be well worth it to purchase the insulated wrenchs that have only one mechanical end.  This way if you should drop it

while servicing you batteries, no instant short if it gets across two poles.

Anyway, be safe with that DC, it loves to bite ya. 

Cliff

[tekebird]

another battery related safety message:

While a younger lad than I am now, being forced into Underaged labor for my folks Charter Coach business, I was servicing the fluid levels in some 8D batteries.

while replacing the caps I pressed one down with it angled with the hi side towards me.

the preasure caused by pressing the cap down caused a jet of acid to squirt directly into my eye.

I  imediately went inside and began to flush my eye.....we then treked off to the emergency room in the "77 oldsmobile custom cruiser station wagon...as we rolled into the emrgency room landing pad I got out.  As my dad pu the car in park the car coasted a bit on the slight incline and pinned my foot under the tire......note no preasure on the foot at this point.  I brought this to my dad's attention and he proceded to put the car in gear.....and drive over my foot.

Now prior to heading to the hospital my mom called and gave them a heads up..........so as I hobble into the ER they had no idea what was going on........

Quite amusing in retrospect.

Moral of the story.

Wear safety glasses
Do not exit the vehicle till it has come to a complete stop.


Outcome.......mild corneal abrasion.......a few weeks of goo in my eye and a patch......almost good as new..........ended up needing glasses but with my genetics that was probably nature at work and no cause of the accident, either of them.....