Li-ion charging fire risk

T

twyfordbridge

1 mW
Joined
May 15, 2007
Messages
11
Location
Essex UK
Hi again,

I posted the "Can you help a clueless newbie please" a few days back and although I think my problem has been resolved (thanks to you), faulty battery, I still have some deep fears.
Before I ordered the kit I emailed the company some questions. I have pastd the relevant ones below together with their response, but after reading 'Gardeners' reply on my initial posting (he has the same kit as me from the same supplier) I am concerned. Gardener says "the corner of the plastic battery casing melted" and suggests "Dont leave it unattended whilst charging" - Does this sound like a safe system? - Personally, I didnt buy this kit to have to sit watching the battery charging with a fire extinguisher in hand. The charger states "For indoor use only".
Gardeners melted battery case sounds like a bit of a near miss.
(Paul-Did you inform EBS of this, if so what did they say or do?)

Below is the corres between the supplier and myself:

5) In your 'Buying advice' pages you spoke about the dangers of some batteries exploding/catching fire etc when they don't have a decent battery management system and of possible cell failure. Are the batteries you supply protected against such problems?

Yes. definitely. They have 5 safety control circuits.

6) Is there a guarantee with the motor and the battery ?
Yes 1 year all parts manufacturers warranty, battery 6 months which is standard for the industry.
---------------------------------------------------------------------------------

I just wonder whether you would have concerns. Are there safety regulations regarding their sale/use in Uk. Although the battery charger itself shows the EC safety mark, there is no markings on the battery itself and I am told by the supplier that the Battery Management System is built into the enclosed battery. No special warnings came with the kit regarding charging, so if I charged it indoors (charger is "Indoor Use Only") and two hours later found my kitchen on-fire, who would be responsible?

Richard.
 
I'll just note that, like others for perhaps different reasons, I suggested you buy a NiMH pack specifically because of the fire risk with lithium-ion and lithium polymer (the risk is much less with the more expensive, 2nd generation lithiums, Li-Fe and Li-Mn). IMO, after melting a couple lithium ion cells myself, systems based on either of these are for people who have studied lithium systems in depth, know the conditions under which problems can occur, and the warning signs of a problem in progress. Some lithium battery management systems (BMS) and chargers can be prone to failures too, and so though helpful, are not a panacea. I use 300 lithium ion cells I soldered myself, and no BMS. I studied at these forums and other online sources for literally 3 months before choosing to go this route and still ran into potentially catastrophic problems in my early designs that required I re-solder the entire pack. But it works great now! :D
 
Call me " Paranoid Android " but i have the Li-Mn lithiums on hand for testing right now and i still charge them on my glass-top stove, while i'm at home, if i have to leave for any given amount of time.. i disconect it.

I keep my DVM (Digital Volt Meter ) on hand and check the pack voltage every now and then, and touch the pack checking for any heating ..

This is with what is considered a quality pack ! with a good BMS..

IF i had Xyster's bike, i'd have to buy a sprinkler system for my metal shed ! lol.... :D
 
I think it's wise to be concerned. I wouldn't charge when you are not nearby, and I would keep a fire extinguisher nearby and I would recommend at least having a plan as to what you would do if you did have a fire. Also contrary to popular opinion, the bigger problem with a lithium ion battery fire is the toxic fumes, not the heat of the blaze. So think of how you would deal with this as well. I would also be careful not to drop the battery pack. I'd treat it as something more delicate than a lead-acid pack. Normally, you wouldn't purposely drop a battery, but I would treat this pack with more respect than one normally give a battery pack.

But bear in mind many (most?) modern electronic devices have lithium ion (or the equally problematic lithium polymer) batteries in them. Apple iPods, Canon digtal cameras, laptops, cell phones... they are all using fundamentally the same technology as your battery pack.

I personally don't think there's an obvious inherent danger in what you are doing. After all, we don't particularly worry when charging a laptop... But it's best to plan ahead and take appropriate precautions.
 
Here are a couple of pics of my first battery pack.

I contacted EBS about it and they were very concerned about the failure. They asked me to return the pack, which I did and they immediately sent a replacement one + charger, so I can't fault them there. I did ask if they would send me a Nimh one instead but they wouldn't but I can't really complain about that.

I don't know what caused it to burn like that. It probably happened while charging which is when just about all problems occur. I don't know the chemistry of this pack but I guess it must be lithium cobalt. After this incident I am not too keen on li-ion as you can well imagine. This pack has a Battery Management System and the supplied charger was used. I did not drop it or damage the pack in any way.

As for the safety of the pack, I store mine outside in a garden shed/store. At the moment I charge it in the conservatory (only when it's nice and cool in the evening) and don't charge it when anyone is near (like my wife + kids). My plan if it goes up in smoke is to exit the house immediately and call the fire brigade. I don't fancy a lungful of lethal fumes really.

I don't often use the pack now since the Nimh is so much better. I would sell it / give it away but I couldn't inflict it on someone else with a clear conscience. Does anyone know how to safely decommission a li-ion battery pack? I definitely can't just take it to the local dump and drop it in their battery bin!

I'm prepared to believe EBS when they say the failure/burning was a one off so maybe I'm being paranoid/over-exaggerating the danger but I for one feel so much safer using Nimh. Besides, I can't really charge the li-ion at work as the health and safety guy would have a fit as he has to test all electrical appliances for safety before allowing them on site. I can just imagine his response if I showed him what happened with my first pack.

I think you'll be fine using the replacement pack but just make sure you take sensible precautions while charging it and if possible don't store it inside the house.
 
I would sell it / give it away but I couldn't inflict it on someone else with a clear conscience.
Click to expand...

If you're really looking to dump it, inflict it on me and keep a clear conscious! Seriously. I'd pull the cells, load test them, charge test them, and build a little pack for bike lights -- or if the good cells can take it, an 8-12v boost pack for my Currie so I can move the 30 lithium cells I put on the Currie back to my X5. I've got the chargers already. Just not sure how much I'd need to pay for shipping from the UK to the USA ...
 
Wait they plugged the batteries directly into 110 volts I can plug a hole shit load of things into 110 and watch the explosion. Plug a tank of gas into 110 and watch the explosion.

Thats just sensationalism and scare tactics

Handled with reasonable care and treated as a large energy storage medium like gasoline or propane. LI-ION batteries are safe

Mark
 
The 4th of July is coming up and I have a bunch of old Li batteries. So all I need is an old extension cord? :twisted:
 
Thats just sensationalism and scare tactics
Click to expand...
Agreed. There's lots of videos of people doing silly things with lithium ion batteries and they result in a fire, and a few videos of people (out of tens of millions) who are using the batteries normally and have a fire.

Handled with reasonable care and treated as a large energy storage medium like gasoline or propane. LI-ION batteries are safe.
Click to expand...
Agreed, as well. I believe it is wise to treat lithium ion cells carefully.

A typical notebook/laptop computer has been 6 and 12 cobalt lithium ion 18650-form-factor cells in it charged with a BMS. People think nothing of the dangers of charging a 12 cell laptop battery. They are widely used consumer products. There have been a couple of reports of fires, but given the massive number of these devices in use, the liklihood of a laptop fire is statistically small. In fact, I would argue - without checking the statistics - that a typical toaster (or a microwave or stove-top range) is vastly more likely to cause a large fire than a BMS-equipped lithium ion pack.

We all know the dangers of not cooking something and then walking away. No one shows videos of people sticking a quart of cooking oil on a stove range on high heat for an hour. I bet you could make a pretty big fireball doing that. But if you made a video of someone doing that, people would say "well, that was just a stupid thing to do". So if someone is dumb enough to plug a lithium ion pack directly into 110V AC, we shouldn't say "wow, lithium ions are really dangerous", we should think to ourselves "well, that was just a stupid thing to do".

It is a good idea to have a fire extinguisher not too far when charging lithium ion cells (although, that said, I think it's wise to have a fire extinguisher not too far from any large battery charger - I've done some damage with NiMH cells in the past too). It is wise to plan for what one might do if things go wrong. It is wise not to put a lithium ion pack on the charger and then drive off in ones car for a couple of hours (but then I won't run the AC, or the clothes dryer, or the dishwasher if I'm away from the house too). It is wise to be careful not to drop a lithium ion battery pack. It is necessary that there's some form of BMS circuit on any cobalt-based lithium ion/lithium polymer pack.
 
http://www.youtube.com/watch?v=vS2hGoJVmlA&NR=1 night explosion of lion batteries
 
You do not need a class D fire extinguisher for a secondary lithium ion battery fire.

There's a big difference between primary (non-rechargeable) and secondary (rechargeable) lithium ion batteries. Primary cells contain metallic lithium and need a class D extinguisher. Secondary cells only contain lithium as a salt (in the chemical use of the word "salt") and can be extinguished with a standard ABC fire extinguisher.

(note section 8.3.2 on page 13 the section that says that ABC extinguishers are recommended)
http://ehs.whoi.edu/ehs/occsafety/LithiumBatterySafetyGuideSG10.pdf
(note page 23 - the section on the fact that halon fire extinguishers are effective with 18650's)
http://www.fire.tc.faa.gov/pdf/systems/Lithium-ion_battery_04112006.pdf

There are several other MSDS datasheets for 18650 batteries that say much the same thing as the documents above. The FAA one is interesting because they actually test the halon at differing concentrations.
 
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