OT Car Battery Explodes

STOP FORGING ME!!!

--
Dr. Robert Bear, MD, FRCPC, (ex Vice Dean, Not James)
American Board of Internal Medicine & Nephrology Certification
Clinical trials, renal soiling, DEPENDS research,
Dialysis population, no boners research
Euthanasia Certified; Uncontrolled Pissing Expert
Telephone 780-407-7239; Fax 780-407-7771
rbear@ualberta.ca

Yea...i thought of that. So...that seems to leave out low-level charging over that 2 hour period, implying a higher charge rate and over a shorter period of tie and "recent" in the chain of events..maybe during the last half hour?

CEASE AND DESIST!

-- Dr. Robert Bear, MD, FRCPC, (ex Vice Dean, Not James) American Board of Internal Medicine & Nephrology Certification Clinical trials, renal soiling, DEPENDS research, Dialysis population, no boners research Euthanasia Certified; Uncontrolled Pissing Expert Telephone 780-407-7239; Fax 780-407-7771 snipped-for-privacy@ualberta.ca

Of course not...they just "expand rapidly"...

Noe THAT scenario seems to be a better fit to the OP puzzle!

Use the "diet" variety?

-- "For a successful technology, reality must take precedence over public relations, for nature cannot be fooled." (Richard Feynman)

Those are *supposed* to incorporate catalytic recombination of H2 and O2, with resealable vents in case of pressure build up.

Maybe the cheapo ones cut corners.

I would have thought that somebody would have done the sums so that, in the case of an internal ignition source (bad spot weld or whatever they use), the case would contain the explosion of the free gases present.

Unless a resealable vent sticks shut. Compression will make things much worse.

--
"For a successful technology, reality must take precedence 
over public relations, for nature cannot be fooled."
                                       (Richard Feynman)

Me again Just to clear up a few questions and issues. I phoned the battery centre. There are no cracks or dent on the bottom of the battery. I checked last night and again this morning. There is a nice acid drip trace on the paving but it was created when we pushed the car out of the garage - not on the way in. The trace also stops where we washed the engine down.

The battery was well secured but not over tight.

The battery exploded immediately on the first attempt to start the car. Obviously the car never started. I also checked the wiring but could not see any obvious shorts or areas where the cable to the starter shows any signs of wear. Will check again in daylight. After we replaced the battery the car has already started at least 10 times without sign of problems or loud bangs.

- - - - Another exploding battery story. Batteries do explode when they are shorted. A friend of mine has a good story on how large 2V marine cells exploded during a Y2K test.

It happened at a large UPS installation with a 3ph inverter that powered an IBM computer centre for a city. After the UPS switch over test was completed successfully the one guy proceeded to blow dust out of the inverter circuits that were inside a large wire cage. The cage was closed and locked There was a loud bang - something shorted and then shorted more things. Trips and fuses did not operate as planed. The inverter circuits and the DC battery feed circuits in a separate cage caught fire.

The DC cables started to heat and the cable insulation started to melt in the next door battery room. Every thing in the battery room was wood - The tables for the batteries and the support structure for the cable ducts. The ducts were however metal. As the cable isolation melted there were cable to cable and cable to duct shorts. More than half the 50+ batteries exploded and half of the remaining were cracked. The guy in the cable room ran around to check what was happening in the inverter room so no one got acid burns. The battery room also had a special floor to contain acid spills.

Someone switched of the building's mains supply and phoned the fire brigade. The gate motor for the huge security gate did not operate as there was no power and the fire brigade could not enter until they managed to locate the manager to find out where he keeps the key for the emergency lock for the gate.

Luckily nobody was injured and everything was insured. The fire was contained to the inverter room. I should also mention that the starting battery for the large standby generator, outside the building, also exploded a month before this disaster. It was traced to a faulty charger that overcharged the starting battery.

He also mentioned that their actual Y2K changeover was a rather uneventful affair.

Have a nice weekend.

Gerhard van den Berg

I was up, way too long. :(

--
Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.

Ruins your liver :-) ...Jim Thompson

-- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

| 1962 |

Democrats are best served up prepared as a hash Otherwise my dogs will refuse to eat them :-)

IMHO a starter is basically a short already! Mike

IF it doesn't spin.

Wonder how old a Corolla? ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |

          Democrats are best served up prepared as a hash
           Otherwise my dogs will refuse to eat them :-)

(...)

Gerhard states in a subsequent post that the car started properly several times, after he replaced the battery. No mention of having replaced the starter. I conjecture we are discussing a broken battery design as a root cause.

--Winston

This economy is making us all stronger. Five years ago, I couldn't carry $70 in groceries with only one hand.

The battery had developed an electrical open circuit in one of the inter-cell connectors. When attempting to start the car, the gap in the connector fizzed and produced a perfectly stochiometric H2 + O cloud, got hot and developed a spark that ignited the gas. it is not all that uncommon.

Jon

That's not an auto battery.

A properly capped battery is designed to keep both solids and liquids from getting into the cells. We're not talking about a battery that has been uncapped.

Which it won't - at least not from a little baking soda that "inadvertently falls into" the cells. You need one helluva lot of baking soda to neutralize the solution in the cells. You would have to work hard and long to drop baking soda onto a battery to the point that the battery failed.

So in your opinion it's ok to add "clear water" to the cells without checking whether it's full or not? After all, you think that the water will be funneled in to the cells.

Ed

(...)

It is the same design as an auto battery, for the intent of the discussion. As is this similarly defective design sporting a funnel feature around the fillers:

I wash off the top of my modern auto battery with a baking soda slurry. Some slurry is bound to get trapped in the funnel formed around the filler caps. It dries. When I next fill the battery, those caps will be removed, yes? Bingo, basic material washed into a cell. My thoughtful maintenance ironically just cost me a battery.

If I add just enough base to 'mismatch' just one of the cells, I've made a 'dead battery walking'. No amount of equalization voltage will be sufficient to recover operation. Before very long, that cell will experience 'reverse charging' and it will make the entire (series) assembly unserviceable.

It is not necessary to completely neutralize all the cells. Just weaken the acid concentration in one cell.

I find that when a car battery dies, it is *normally* the result of a weakness in just one cell. You have seen the same thing, yes?

(...)

A tap - water rinse will not leave a significant deposit of basic material near the fillers. Only distilled water is added to the cells. The danger is in washing dried base into any cell during filling or worse yet, removing the caps and wiping the top of the battery with a slurry - soaked shop rag. Seems like a reasonable thing to do, yes? (It isn't.)

--Winston (Wonders if Ed owns a NAPA shop...) :)

--
No, your stupidity would have.

If you know that the slurry will dry and leave baking soda powder
around the filler caps, then it seems if one would think about it a
little one would hose off the slurry until only water was left around
the filler caps, the result of that being that when the water
evaporated, Voila, no residue.

How could that be? You said: > "... should be innocuous since it won't even change the pH of > the solution"

Would it have cost me a battery or not, in your opinion?

My points are that:

1) It is not necessary or economical to bring any basic material in contact with a lead acid wet cell unless one is trying to neutralize it, say in an emergency situation.

2) It is much simpler and more economical to rinse the outside of the battery with tap water, sans baking powder or any base. A lead acid wet cell of any type can be handled that way in a safe economical fashion.

Then we are morally obligated to warn laboratories everywhere that one cannot neutralize an acid by mixing in a base.

(You go first.)

Explain why mixing sodium bicarbonate (alkaline) with our sulfuric acid solution (acidic) would not tend to make the mixture more neutral than before mixing (that is trending toward pH = 7.0) I readily admit that you could put all my chemical knowledge in a thimble and have room for a medium sized battle ship. :)

I believe that the pH of the solution *would* tend towards neutral pH, however. (Call me a heretic.)

I'm not so sure. I suspect that recovering the operation of a wet lead-acid battery after significantly weakening one of it's cells in that manner would require the whole battery to be disassembled, drained and rinsed. then the electrolyte replaced with fresh and a complete equalizing recharge. Depending on the number of charge / discharge cycles done after neutralization of the cell, the battery may not be recoverable without heroic surgery, to the point that one could reasonably object that 'it isn't even the same battery' afterword.

I disagree. I expect that the damage to the battery would be cumulative in normal use. The more basic the electrolyte, the sooner that the battery would become unserviceable.

--Winston

=A0 =A0 =A0 ...Jim Thompson

If I had a Ph.D. and was addressing an academic gathering, I just might. The person introducing me probably would. Who am I to blow against the wind?

=A0

I don't see the difference. Either appendage establishes one's qualifications in a qualification-rich setting.

-- Joe