Hi all,
The family went to Huntsville, AL yesterday to see the space and rocket museum there. On our way we enjoyed seeing an MCI, GMC, and two Eagles. It was about a two hundred mile round trip for us and we returned home at around 8 in the evening.
When we walked into the bus we smelled what we thought was a bad mold smell, so off I went to investigate.
I thought that it must be the gray or black vent or just the gray tank leaking in bay 3. We cleaned the bay floor, drained the tanks, put in more smelly stuff to hide the odor of the other smelly stuff, but to no avail.
We turned on the fantastic fan, opened the windows, turned on both A/C's to try to run the smell out, but it only got worse.
I then went into bay two where I had refilled the propane tanks the day before. The smell was stronger. It had a strange gassy/rotten egginess to it that I assumed was a leaky valve. So off go the tanks, out of the bus they come for a testing. We go back inside the bus, and I lay down thinking I'm tired and I'll fix the propane tomorrow in the daylight.
My dear wife says I SHOULD GET UP TO GO FIND THE PROBLEM, IT'S WORSE!!!
I go back outside to look again. This time I look in bay 1, the battery bay. I smell the smell stronger than ever, and when I lay my hand on the 8D battery on the left, it is VERY hot.
My wife comes out to hold the light as I am now a bit frantic. I know I have to get that battery out of there because it is producing a bomblike condition. I begin to remove the cables from the battery. The whole time I am telling her that you must be extremely careful in this situation not to create a spark. i got the cables removed from the offending battery, But I was stupid. I did not unhook either cable on the other battery.
I saw the live cables going toward each other, I reached in to try to stop them. My hand reached them at the same time they sparked, right on the top of the bad battery.
BOOM!
I got lucky, I still have my hand and my sight.
PLEASE be careful when you all are working on your buses, it really can sneak up on you.
Devin
Devin,
Sorry to hear about your troubles.
It just reminds all of us to be careful in everything we do.
IT also gives you a good chance to try out the New, Clean underwear you got for Christmas! ;D ;D ;D
Dallas
Switch off the master disconnect and walk away just walk away. No master disconnect? Another good reason to have one.
Hello
First, glad you are still with us, Devin, and thank you for sharing so the rest of us stay on our toes!
As Lee suggests, master disconnect! There are coaches out there that the master doesn't cut-off everything, including some high powered chargers.
In the design phase, thought should be given to a way of having the battery main switches in a stock location. The firefighters know where they are, and so do other busnuts....
Negative wire gets removed first. Or the wrench you are using becomes a welding rod....
happy coaching!
buswarrior
I had a professor in college that had a battery blow up in his face while he was jumping a van off. If he hadn't been wearing glasses...
I am very glad you and your family are ok.
Devin:
Gads, glad you're OK! :o And thanks for sharing your "war tale." It's the wisest of us that are lucky enough to survive the mishaps... and then tell everyone else their stories.
BBS:
To prevent further disasters amongst us, and assuming one has already installed a disconnect on the coach batts, would another good safety device be one of those massive "disaster" fuses like I have on my house batts? If yes, how "big a boy" would one need? I'm told a DD can pull a bunch of amps to start when cold.
Thanks,
Brian B.
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.
While the warning was not explained in the manuals that I have seen, it seems to me that what must be happening is that the battery negative and the inverter neutral output are connected together, at least when it is inverting.
If the negative is disconnected, you could feed a pulse of AC output into the DC input.
Since a number of inverters turn themselves on when furnished battery power, disconnecting them when they are turned off is insufficient because of the possibility of a jiggled connection turning them back on during the operation.
Perhaps a warning posted at the battery compartment could help?
Tom Caffrey
Devin,
Thanks again for sharing this with us, more things to document to do before putting my Eagle back together, I am glad that many are now sharing bad experiences we do have so that we all can benefit not thinking perhaps that little ole 12 volts can also ruin your life or your eysight or a number of things. Seems like the Cut off switch is the answer, but will wait on other feed back from busnuts on this post.
Again glad you did not get injured, no bus is worth it to me. Heck not sure if my bus will ever get out of the bus port at this rate but she'll be as safe as all your suggestions convince me to make here for my wife's next husband. LOL.
Take care Devin,
Gary
Every battery should have a separate disconnect switch. You can get the "green knob" ones from JCW for about $7 and they are worth every penny. No sparks, no relays.
I became converted after a stuck starter solenoid on my Jeep almost burned out the starter, it was smoking and too hot to touch.
No more frantic searches for wrenches.
Devin, glad all is ok! I have a simple tip I use everytime I disconnect batteries that would have eliminated yer spark! I take a short piece of old hose and slip it on the loose cable end as I disconnect them this way they are protected from shorting out to anthing! Again glad you weren't injured! I had an idiot start trying to crank his car once while I was hooking up the cables while on a service call! His insurance company paid for an ambulance ride, a night in the hospital, 90 days "vacation time", a whole bunch of doctor bills, a home nurse for the 7 days I had bandages over my eyes, a bunch of good pain killers, new carhart jacket gloves and cap, new paint job on front 3/4s of my tow truck, and what ever the damages were to his car! I paid for the beer! BK ;D
BK; that short piece of hose idea sounds great. A step futher might to install a piece of hose on the cable when it is installed, then when the cable is disconnected just slide the hose up over the end. No hunting around for little pieces of hose when you need 'em. Just my idle thinking.
Dale MC8
When DC current is flowing (battery charging or discharging) it is impossible to break the circuit without a spark. Obviously, the higher the current, the bigger the spark. The only safe method is to break the circuit remotely from the batteries.
Quote from: Busted Knuckle on January 09, 2007, 09:39:56 AM
Devin, glad all is ok! I have a simple tip I use everytime I disconnect batteries that would have eliminated yer spark!
I agree with Stan. In Devin's case, this would probably have eliminated the spark. However the big problem is when disconnecting a battery, there is a spark generated when the cable is removed from the battery post. That is if the battery is either charging or discharging. In this case, the short lengths of hose would not be of any help.
Richard
Thanks Tom!
I forgot about that bit, since I have a big DC circuit breaker on the inverter.
I would hope that every busnut has the inverter wired with some protection and not wired directly to the batteries.
Dale, smart idea, install the assistive device where we can't lose it!! Great!
happy coaching!
buswarrior
thanks for sharing your experiene. I had heard of batterys going BOOM and saw it for the first time this summer. Not a pretty sight. I keep a pair of safety goggles in the battery compartment in a ziplock bag, I do nothing in there, not even check the water without them. I will add some hose to this bag!!!
The post about unhooking the neg cable first rings a bell. I am sure that is what it says in my Zantrex manual. But the fuse is in the positive wire. So if I blow a fuse am i going to ruin my inverter?
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
Quote from: pvcces on January 08, 2007, 07:42:26 PM
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
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.
Quote from: Jeremy on January 10, 2007, 02:32:07 AM
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.
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
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
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.....