Lead-Acid Battery Failure

[davidbeach]

I'm working on an "Outage Drill" scenero for work and I want a failure of a substation battery, a battery comprised of 60 glass jars each with one lead-acid cell. A simple failure, an open somewhere in the string will create plenty of chaos all by it self, and I can live with that. But are there any reasonably credible way of having a catastrophic failure, particularly one that might involve an acid spill and/or a smokey fire? Acid splashed everywhere and smoke contaminated equipment will make the exercise even more "fun" for those envolved. All ideas appreciated.

I'm sure I could get more answers in some other forums, but don't really want a widely aired discussion.

 

[MikeHalloran]

Suppose you had one cell going flat, and you wanted to replace it. ... without taking the battery out of service.

You could parallel it to a known good cell, then remove the bad cell.

If you got the polarity of the connections to the new cell wrong, I'm pretty sure you'd get a hydrogen explosion.


....

Something similar happened when my wife helped a friend jumpstart a borrowed car.
They connected red to red, red to red, black to black and black to bla ... BOOM!
Both batteries exploded.

Luckily, no one was seriously injured, but that really was just dumb luck.

The owner of the borrowed car had replaced the battery + wire with a black one, and had also replaced the battery -/ground wire with a red one. Bad practice, but not illegal, and not particularly dangerous, until you lend the car to an innocent.







Mike Halloran
Pembroke Pines, FL, USA

 

[ScottyUK]

We had a serious problem on a turbine emergency battery - 110V at about 1500AH - where a couple of cells had developed cracks in the corner of the casing, resulting in the loss of most of the electrolyte. The damaged cells obviously compromised the whole battery, and the decision was made to disconnect and bypass the damaged cells. The electrician doing the bypass made a mistake when fitting the temporary inter-cell links and managed to short out three or four cells in a closed loop.

The heavy cable link smoked, then glowed red, orange and then bright yellow. The external fire brigade were en-route while site staff attempted to use a service hose to cool down the installation. It took a fair bit of effort to convince the brigade that spraying water on this big battery was a better idea than waiting for the fire to go out, risking the release more acid and fumes, but they set up a free-standing water monitor and sprayed it for an hour or so. No inuries, although the battery was a real mess.

 

[waross]

I have seen a couple of batteries explode from steam pressure. This results from the short circuit current boiling the electrolyte and the resulting steam pressure blowing out the sides of the battery case.
I have also cleaned up numerous messes when a mixture of hydrogen and oxygen in the top part of the a cell ignited. This is much more violent.
This was a common mode of failure of the battery in a standby generator set when a small battery charger was fitted. I no longer spec battery chargers for standby sets and I disconnect them when I encounter them in the field.
The automotive type alternator does an adequate job of charging the battery. When the battery fails, the set does not start when called and then the battery is replaced.
With a charger in the control panel the battery will continue in service for a few months longer but then the failure mode is explosion.
The hydrogen explosion generally cleans the top of an automotive battery off level with the top of the plates. Small amounts of acid are well distributed throughout the room.
Don't let large battery banks deteriorate to complete failure.
Remember that when one cell has an accumulation of hydrogen others cells may also have hydrogen present due to recent charging and may also detonate.
I hope these anecdotes help.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[stevenal]

Have you spoken to your local fire department? I would think they would have the smoke and fire simulation devices needed for their own training. Seems like you would need their involvement in the drill anyway, unless you train with SCBA.

 

[davidbeach]

Nobody would actually be going to the the substation, the drill is more at the corporate level, how would we respond to the loss of a critical substation due to battery failure, and who would we dispatch while those who might be dispatched are elsewhere doing real work. Simple failure to trip due to a battery open circuit will create enough havoc and that may be as far as it goes. The more catastrophic the battery failure, the longer the projected outage would last, the more the engineering and management functions would be stressed. A simply station wide failure to trip can be resolved and things put back together in a few hours; if all the relays and wiring are contaminated then it will take a bit longer. Since I've already seen one substation No-Op during a fault due to a failed battery I don't consider that part too outlandish, but I'm interested in creating that longer outage without making people just stop and say that it can't happen and not take the exercise as seriously as they might. The battery failure alone should get lots of attention.

 

[stevenal]

David,

I believe any lead acid battery is subject to thermal runaway, creating the type of mess you describe. But if you want a nice extended outage, you don't need to look any farther than failure to trip. Many years back at the WPRC, a gentleman described a situation where a charger was left off following maintenance. When a feeder failed to trip, the switcher fed from the same battery also failed to trip. Distance relaying upstream was not configured to see past the transformer impedance, so the transformer fed the feeder fault until it faulted internally on the primary winding, and upstream protection finally tripped. He showed a video of the aftermath, and thdestructionon was impressive. I can assure you resolution took substantially more than a few hours.

 

[davidbeach]

In this particular case it would be a major bulk power station and all the lines do get tripped, but the level of the outages will be significant.

 

[TheTick]

Any submarine vet can tell you seawater in the battery well is a huge deal, as that causes release of toxic fumes. Any plausible scenarios you can dream up from that?

 

[TheBlacksmith]

Ahh yes, creation of large quantities of chlorine gas. Not necessarily a catastrophic event for a power station, but deadly in a closed submarine underwater.

 

[JStephen]

How bout vandalism/terrorism?

 

[davidbeach]

Vandalism/Terrorism (aka disgruntled former employee) would be a different exercise scenario. A heck of a lot of fun to put together, but not in the scope of this year's fun and games. Need to get the powers that be familiar with how badly the system will respond for a "simple" battery failure before I spring on them the total mayhem that someone with malice aforethought could create in a few minutes with a high powered rifle and perhaps a length of chain or two.

Unfortunately if I do the battery failure at the location in mind this year, a future disgruntled former employee event will have to be else where and perhaps not quite as disruptive on as wide a scale with as many very vocal customers screaming for service restoration. But that's OK, I can find the loose ends where one good tug causes things to unravel far and wide, particularly in an exercise scenario where I can weigh the dice as much as necessary.

 

[waross]

Is there a possibility/probability of an arcing failure event at a single open cell?

Bill
--------------------
"Why not the best?"
Jimmy Carter