Large Scale Central

Lithium battery fire?

Electronics Power and Sound
#21

Greg- You miss the major point of this.

It’s when they decide to “go off” when NOT on charge…like in the trunk of your car, in a cell phone on your hip (local kid), in your laptop when you’re just sitting there.

When a Lithium decides to fail internally, I am not aware of a “pop-up” indicator that warns you to take it quickly out in the back yard.

And, I would venture a guess (just a guess), that 100MAH single cell packs won’t have the “bang for the buck” that 3AH units might have.
I would further guess it’s like the difference between an M-80 and a full stick, but again, that is just a guess…

#22

You’re right, I did not consider the pack going bad by itself when not on charge.

I have not seen any evidence of anything happening when not connected to a charger. All of my experience has been that they refuse to charge correctly.

What I have seen is:

  1. High internal resistance, or open circuit. My experience has been that these cells just refuse to charge. They are normally discarded at this point, since they are useless.

  2. Failure to retain a charge. The charging cycle completes, but they have greatly reduced capacity. Again, most people discard the batteries at this point, since the run time sucks. Continued attempts seem to yield the same results.

  3. Shorted cells. This is the dangerous one. Depending on the charger, it will either shut off (rare in my experience) or will try to charge the cell resulting in too much heat. Cell packs with a thermal shutoff, like laptop batteries, will normally permanently open the circuit, putting you in situation 1 above. If this does not happen, then you can have a meltdown.

If the battery is not connected to a circuit, I cannot see how anything can happen. If the battery is connected to a load, you just have a low or no power situation.

I can only understand something bad happening if you try to charge a bad pack and there are no safeguards in place, such as the thermal breakers or bad charger.

Dave, did I miss a situation in the above analysis?

Regards, Greg

#23

Yup.

Unless I am not understanding some of your phraseology, an R/C aircraft with Lithium Batteries in the trunk of a car is not on charge.
Since it is not, “High internal resistance, or open circuit” does not apply. “Failure to retain a charge”, possibly, but we don’t care in this instance.
“Shorted cells”. Probably, but we are not charging.

Let me one more time run this past you.

In one of the model airplane forums, there was a post about an aircraft placed in the trunk of a car, and the ownwer was over talking to his buds, and the car went off.

Now, we do not have a charge source, the power switch is off, so no circuit.

How about the kid with the cell phone on his hip?

Just how long an extension cord did he need to be walking down school hallways with the phone on his hip and it blew?

Do we need to re-interate that it was NOT on charge?

Thermal protection is only for the line.
Either input or output.

If the cell torches, you could have four hundred pounds of thermal protection on the cell and it would make zero difference in the outcome.

I will dig out my newspaper clippings later and maybe even scan them.

I have one here on HP laptops, and the 135,000 LiIon packs that were recalled for “melting”.
Yeah, right.

And the Dell the torched.

I could also keep old boxes of dynamite in my basement, but I don’t think so.

#24

The power has to go somewhere if the electrolite breaks down which it can through chemical degradation . The power produces heat , mainly because the current flow is short but vicious.Internally , no external connection . You can induce such a situation in controlled conditions by putting a near short across a "rejected " cell --one that you have found won’t charge .
Just do it at a distance and watch the result through binoculars . This is true of any energy storing device -a capacitor will get hot too if you overstress it . But , due to its inherent lack of storage capacity as found in a battery ,
it is comparitively safe because the discharge is pretty rapid . Hence the average power is low .
An "ordinary " battery–non NiMh–has electrolite which breaks down gradually , the resulting current is low and leaks the power away slowly .This is an over simplification , but you should get the idea , I think .
I will not use NiMh batts,simply because of their troubled history .
Given what you now know about them , are you likely to stick a set of 4 AA size in your $1000 camera ?
Not me pal , and we should be thankful for the warning .
Mike

ps the question to ask here is , Do the military or Nasa use them in vital long term devices , e.g SAR beacons ?

#25

OK, so I did more research.

There are many reports of primary (lithium-metal, non rechargeable) batteries and burning and fire. There are fewer of lithium-ion, but still it’s happened.

Looking at all of those, most fires were due to shorting the battery.

Some were due to damaging the battery, and causing an internal short, and thus fire.

Some, the least, were unexplained, i.e. there was no evidence of a short or damage.

So proper handling should avoid the most common problems.

Can a lithium ion battery develop an internal short that also shorts the battery while there is enough charge to catch it on fire? I think that’s the question.

So, I now understand your strong feelings, that they may be unsafe no matter what, just sitting there.

I don’t share the same level of concern. I do share the concern for poor charging, damage, bad chargers, unattended charging, storing in a hot place, letting them get knocked around, tossing a battery in a suitcase.

I’m not so concerned that I’m disposing of all my electronics with lithium batteries.

But, after doing this further research, I’m going to the garage, getting all the loose li-ion batteries that are on the shelves near the charger, and slowly discharging them one by one on the concrete, and then throwing them away.

So, your concern has made another (at least half) convert.

Regards, Greg

#26

Okay.

You’re gettng there.

Now, we just back off a bit and look at the big picture.

There were several NiMH train incidents of note, many many other NiMH incidents, UNTIL the charger technology reached the battery technology.

Now, NiMH are used safely, daily, and I stock, sell and install them.
Until the technology curves crossed, I would not.

Until Lithium technology catches up, I am not interested.

Damaged batteries, yes, can cause it.
Like crashing an airplane (some, but not all causes by far), dropping your cell phone (what, you’ve never dropped the phone? If you do, what is the emergency procedure?), and if they can be damaged, exactly how much force will do it?

A crash off your elevated railroad?
A hard coupling?

I don’t do Beta testing, not and have to pay for the priviledge.

When the bugs are out of them, fine.

Talked to a guy today using them, and he watched a helicopter at a meet up in Chilliwack that had been charged, was on the line after waiting to take off (no crashes, not currently on charge), and it blew. Took the whole nose off the helicopter.

Why?

Not charging.
Not shorted.
Not crashed or dropped.

Remember theorums and postulates?

All it takes is one failure to disprove all the safety articles, but I’ll give you better odds.

TOC

#27

Okay.
Read some of this.
Fist one, please note the large read warning:

http://www.helihobby.com/html/disclaimer.html

Now the Feds are worried, too:

http://72.14.203.104/search?q=cache:ScGKQRcks64J:www.unzco.com/IndustryNews/hm224e.pdf+lithium+batteries+model+airplanes&hl=en&gl=us&ct=clnk&cd=44

of course that was probably based upon this:

http://www.phillyburbs.com/pb-dyn/news/103-07122006-682788.html

or this hobby warning:

http://hometown.aol.com/kmyersefo/liposafety.htm

How much more do you want?

#28

Chad Konefe has posted an update at the AC Off Topic forum.

Entitled “fire up date”.

It would be very helpful to other consumers if Chad could spell out exactly what brand of Lithium battery did cause the fire so they can be avoided.

#29

Note: the FAA restriction is on primary lithium cells, i.e. non-rechargeable, lithium-metal cells, not li-ion rechargeables. (don’t get off on this, just keeping the record straight.)

I found 2 FAA investigations on rechargeables.

Chad says it was not Aristo li-ions, but the same type of battery. Well, that will scare the hell out of a lot of people.

Track power all the way, if the rails catch on fire, they are outside with the power supply!

Greg

#30

What the FAA is not now resticting is personal rechargeables.

Bulk shipments of same: RSPA is not prohibiting the shipment of secondary (rechargeable) lithium batteries or those electronic devices (e.g., laptop computer, cells) that contain or are packed with small lithium batteries, and passengers may continue to bring personal electronic devices on-board either in carry-on or checked baggage. RSPA is continuing to evaluate the risks posed by rechargeable lithium batteries, as well as all lithium batteries on-board aircraft, either separately or as part of equipment, and seeks comments on ways to mitigate these risks and the costs of doing so.

NTSB: Several other incidents have occurred in recent years in which lithium batteries - used in laptops and cell phones - have caught fire aboard airplanes.

Less than two months ago in Chicago, a spare laptop battery packed in a bag stored in an overhead bin started emitting smoke, chief crash investigator Frank Hilldrup of the NTSB testified Wednesday.

A flight attendant used an extinguisher and the bag was removed, but the bag caught fire on a ramp, Hilldrup said.

Investigators in the Philadelphia fire found that several computer laptop batteries were on board the plane, and that in many cases portions of the laptop batteries had burned, he said.

So, that’s the story.

You decide.

#31
Greg Elmassian said:
........if the rails catch on fire, they are outside with the power supply!

Greg


You have a power supply outside???

#32

I won’t tell hip about the local guy and the BridgeWorks outdoors…

Lord help us if we get into ground faults and 110VAC on one rail to ground…