macgyvercanada Posted January 11 Share Posted January 11 Hey all. Was just chatting with a colleague who is a volunteer firefighter. He was talking about a difficult-to-extinguish magnesium fire that they'd recently attended. I mentioned that I was considering the Lynx with its magnesium frame stuffed with lithium batteries and he strongly suggested that I look elsewhere. Not that Veteran has a fire history but if one were to start then it would be a Problem... Quote Link to comment Share on other sites More sharing options...
Paradox Posted January 11 Share Posted January 11 Magnesium alloy. 2 1 Quote Link to comment Share on other sites More sharing options...
macgyvercanada Posted January 11 Author Share Posted January 11 30 minutes ago, Paradox said: Magnesium alloy. Important point. Hopefully the less-burny kind of alloy. Quote Link to comment Share on other sites More sharing options...
The Brahan Seer Posted January 11 Share Posted January 11 This might should your mind at rest... its only 6 minutes but you will learn a lot.. Quote Link to comment Share on other sites More sharing options...
Parker Noodles Posted January 11 Share Posted January 11 34 minutes ago, macgyvercanada said: Hey all. Was just chatting with a colleague who is a volunteer firefighter. He was talking about a difficult-to-extinguish magnesium fire that they'd recently attended. I mentioned that I was considering the Lynx with its magnesium frame stuffed with lithium batteries and he strongly suggested that I look elsewhere. Not that Veteran has a fire history but if one were to start then it would be a Problem... Both magnesium and lithium fires are considered self oxidizing (Class D); the additional "risk" tied to having magnesium in the shell is like putting a gallon of gas on a wild fire, it doesn't change anything, if the wheel catches fire there isn't going to be any stopping it. And, as Paradox said, it is a magnesium alloy which is much less flammable than pure magnesium (those alloys are already used in aircraft, cars, etc). 1 Quote Link to comment Share on other sites More sharing options...
macgyvercanada Posted January 11 Author Share Posted January 11 Quote This might should your mind at rest... its only 6 minutes but you will learn a lot.. I learned that I want the same haircut when I'm an old wise man... 1 Quote Link to comment Share on other sites More sharing options...
The Brahan Seer Posted January 11 Share Posted January 11 This one is about Lithium and sodium (metals) which is quite interesting to see the reaction with. Bare in mind all these and the video above are using the Pure elements in their natural state, once you combine them to other elements their properties are totally different eg Salt is Sodium Chloride. Quote Link to comment Share on other sites More sharing options...
Clem604 Posted January 11 Share Posted January 11 I hope my Sherman-S doesn't catch on fire and it hasn't.....................................yet. Great wheel though! Quote Link to comment Share on other sites More sharing options...
Chriull Posted January 11 Share Posted January 11 (edited) I've heard oxygen is very flammable and it's everywhere - we're doomed Edited January 12 by Chriull 2 1 Quote Link to comment Share on other sites More sharing options...
The Brahan Seer Posted January 11 Share Posted January 11 34 minutes ago, Chriull said: I've heard oxygen is very flammable Actually its not flammable at all, but you can google about that if you want to know more. Otherwise this thread will become one big chemistry lesson. 1 1 Quote Link to comment Share on other sites More sharing options...
Chriull Posted January 12 Share Posted January 12 (edited) To add something constructive - as it seems just using an alloy does not necessarily solve this problem. Here a nice paper titled "A review on ignition mechanisms and characteristics of magnesium alloys" https://www.sciencedirect.com/science/article/pii/S2213956720300335 Seems that some Ca, Be and Y are nice supplements for flame retardant alloys? Here a comparison of a "normal" magnesium alloy (AZ91 & AM60) vs magnesium alloys with Ca and Y https://www.ait.ac.at/themen/casting-technologies/projekte/brandbestaendige-magnesium-legierungen Would be interesting whether and if how much worse some AZ91 or comparable alloy makes an EUC li ion battery fire... The "oldtimer" Ninebot One series already used the magnesium alloy AZ91D. (https://www.newegg.com/p/03Z-00DC-00045) Veteran Sherman S has magnesium alloy rim covers and pedals. In the forum some references are found of Begode (?Monster?) using magnesium alloy pedals. I can't remember any report of a magnesium fire - maybe it was not recognised as such or not "notable worse" than a li ion fire? Edit: Somehow i doubt that (flying) li ion cells cpuld ignite a more or less massive mahnesium alloy block like a pedal? Maybe reading the paper in detail could reveal this? Edited January 12 by Chriull 2 Quote Link to comment Share on other sites More sharing options...
null Posted January 12 Share Posted January 12 I believe the side panels of the EBCP are also in magnesium alloy. Quote Link to comment Share on other sites More sharing options...
The Brahan Seer Posted January 12 Share Posted January 12 4 hours ago, Chriull said: To add something constructive - as it seems just using an alloy does not necessarily solve this problem. Interesting paper, thanks for the link. From the paper although an oxide layer protects the alloy somewhat if the fire gets hot enough and has enough oxygen Magnesium alloys will certainly burn. 2 Questions remain, could an EUC fire create enough heat and provide enough oxygen to facilitate the Magnesium framework igniting too and would the ignition of an Magnesium shell really make that much more of a difference from an already great impact of an Li ion fire ( as already highlighted by @Parker Noodles above. I think from an aircraft point of view (which this paper is ) the potential is certainly there. EUC? Who knows. Something else highlighted that had crossed my mind before is the potential corrosive/pitting/cracking issues historic magnesium alloy wheels exhibited. But I'm sure they don't use pure/ majority Magnesium like they did in the old days. Would they? Nah It will be interesting to see how the bodywork holds up over time anyway. 1 Quote Link to comment Share on other sites More sharing options...
Nostris Posted February 8 Share Posted February 8 On 1/11/2024 at 9:12 PM, Paradox said: Magnesium alloy. Have you never seen a magnesium alloy race car wheel catch fire? It’s very, very scary! I really can’t think lithium batteries in a mag alloy frame is a great idea tbh. 1 Quote Link to comment Share on other sites More sharing options...
Mono Posted February 8 Share Posted February 8 2 hours ago, Nostris said: Have you never seen a magnesium alloy race car wheel catch fire? I haven't, can you help me out (like provide a link to a video clip)? Quote Link to comment Share on other sites More sharing options...
Mono Posted February 8 Share Posted February 8 On 1/11/2024 at 9:05 PM, macgyvercanada said: Hey all. Was just chatting with a colleague who is a volunteer firefighter. He was talking about a difficult-to-extinguish magnesium fire that they'd recently attended. I mentioned that I was considering the Lynx with its magnesium frame stuffed with lithium batteries and he strongly suggested that I look elsewhere. Not that Veteran has a fire history but if one were to start then it would be a Problem... Hard to believe that a magnesium alloy frame should change the (fire) risk assessment for an EUC in any significant way. It looks more like someone couldn't see the forest for the trees. To start with: how much exothermic energy is stored in the frame compared to the exothermic energy stored in the batteries? I am completely ignorant about the values but I'd suspect it may not be more than 20% (and possibly much less) in particular for a large battery. Unless the magnesium alloy fire is more difficult to extinguish than the battery fire (it's probably not), this makes the frame material practically irrelevant for the fire risk assessment. Secondly, a well-done smart BMS and a sturdy battery casing are both probably much much more important to reduce fire risks than the alloy used for the frame. 1 Quote Link to comment Share on other sites More sharing options...
Eucner Posted February 8 Share Posted February 8 5 hours ago, Mono said: To start with: how much exothermic energy is stored in the frame compared to the exothermic energy stored in the batteries? 21700 batteries depending on test method and chemistry have exothermic energy of 0,6 - 1,1 MJ/kg. Magnesium has 24,8 MJ/kg. Li-ion thermal runaway has certainly capacity to ignite Mg. I wouldn't count Chinese manufacturer's using non-flaming Mg alloys, if not specified and independently tested. 1 1 Quote Link to comment Share on other sites More sharing options...
Mono Posted February 8 Share Posted February 8 (edited) 2 hours ago, Eucner said: 21700 batteries depending on test method and chemistry have exothermic energy of 0,6 - 1,1 MJ/kg. Magnesium has 24,8 MJ/kg. Li-ion thermal runaway has certainly capacity to ignite Mg. I wouldn't count Chinese manufacturer's using non-flaming Mg alloys, if not specified and independently tested. Interesting, that is, if the frame weighs 3kg and the battery weighs 15kg, the frame could make a battery fire (15*0.9+3*25) / (15*0.9) ≈ seven times more powerful if both fully burn down? That would be non-negligible Edited February 8 by Mono Quote Link to comment Share on other sites More sharing options...
Funky Posted February 8 Share Posted February 8 And if fire starts - the end result will be the same. Burnt down house/room. And a lot of smoke damage. And maybe even dead body - if you tried to fight the fire while inhaling the magic smoke. Quote Link to comment Share on other sites More sharing options...
Dan Cobar Posted February 12 Share Posted February 12 If you want to play with magnesium fires, you can find fire starters at most camping stores that are just a block of magnesium and some ferrocerium. The Mg. is very hard to ignite in its solid form. But made into fine shavings, a small spark can get it going. Of course with enough heat, even a large block can be made to burn. If anyone has some damaged pedals made of Mg. alloy, perhaps they can conduct an experiment to see how flammable they are. 2 Quote Link to comment Share on other sites More sharing options...
sbb Posted February 16 Share Posted February 16 (edited) On 2/8/2024 at 8:42 AM, Mono said: Unless the magnesium alloy fire is more difficult to extinguish than the battery fire (it's probably not), An Mg fire will hydrolyze the water. You understand what that means in a fire, right? Volkswagen Beetles used to have a mg knuckle in the steering column. Any time the interior of one of those cars caught fire, it was SOP to send a new guy up to try to put it out. The result was always fucking hilarious. Edited February 16 by sbb Quote Link to comment Share on other sites More sharing options...
macgyvercanada Posted February 17 Author Share Posted February 17 20 hours ago, sbb said: An Mg fire will hydrolyze the water. You understand what that means in a fire, right? Volkswagen Beetles used to have a mg knuckle in the steering column. Any time the interior of one of those cars caught fire, it was SOP to send a new guy up to try to put it out. The result was always fucking hilarious. Yeeep I've got a couple of ABC extinguishers handy to where I charge my wheels. Quote Link to comment Share on other sites More sharing options...
sbb Posted February 17 Share Posted February 17 7 hours ago, macgyvercanada said: Yeeep I've got a couple of ABC extinguishers handy to where I charge my wheels. ABC won't touch metal. Metals need class D. That said, ABC could slow fire spread to ceiling, room and contents if you don't asphyxiate. But it won't do anything meaningful for the wheel itself. 1 Quote Link to comment Share on other sites More sharing options...
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