NEW YORK - Fire officials say a massive fire at an e-Bike shop in Queens is now under control.
More than 100 fire and EMS members responded to what became a two-alarm fire, which tore through the garage of the Kings Electric Scooters shop on Jamaica Avenue in Richmond Hill at around 2:30 p.m.
Old work buddy and I were talking about these increasingly common fires. We thought up a design of a charging box for the battery, drop it in and a cooling fan starts as the battery is automatically charged. But IR sensors monitor the batteries temperature and above a certain point the charging is stopped and the fan speeds up for a short interval. If the temp doesn't drop an alarm sounds and the box is sealed. Would need to know about the physics of lithium ion battery explosions to determine if the box can be made strong enough at a reasonable cost to contain it.
Neither of us have any intention of buying any lithium battery powered toys.
No cooling will help a runaway Li battery. And they can run away just sitting there with a partial or full charge. Once that reaction starts, usually because the dielectric film between the Li sheets breaks down due to thermal or mechanical stress, you get a short between layers. This quickly (milliseconds) breaks down more dielectric, allowing more shorting, and then you get to the point where the Li melts and starts to burn. At that point it is "stand back Gertrude" cause that battery is gonna go up. You can slow it down, or you can speed it up, but until it is slag, it's gonna happen. Oh, and water and air both fuel the fire because room temp Li reacts with both, and hot Li reacts to the point where a lay person can't tell the difference between that and an explosion. Oh, and one of the reaction products with water is hydrogen...which also joins the party as fuel...and your water you sprayed on the fire is now a caustic mix of lithium hydroxide, which although not as aggressive as lye or potash is similar enough that it takes special measures to neutralize it.
My thought was that active cooling during charging would reduce the 'flexing' of the internal structure and reduce the fatigue failures inducing shorts. Right now is the time to get laws on the books banning the storage or parking of EV within or under an inhabited building. If they are having these problems with 1%-2% of the vehicles now electric, what happens when it's 10%, 20%... etc.
So if I get this right, one pokey-pokey from,say, a black-tip projectile in an EV battery pack should cause an offending vehicle to both catch fire AND change shape?
Electric bikes are becoming very popular and I bet most get parked in a structure both for security and to keep the battery from freezing in cold weather. Anecdotally, it appears most of the bike “ cook offs” come from the cheaper bikes. I see them advertised for $300 or so. “Townie” electric bikes are $1200-1500 and they claim no problems with burning batteries. I have townie pedal bikes and they start at $700-800.
heh burn that mother down
ReplyDelete“ they believe a faulty e-bike battery was the cause.” why am i not surprised.
ReplyDeleteWasn't big enough...
ReplyDeleteOld work buddy and I were talking about these increasingly common fires. We thought up a design of a charging box for the battery, drop it in and a cooling fan starts as the battery is automatically charged. But IR sensors monitor the batteries temperature and above a certain point the charging is stopped and the fan speeds up for a short interval. If the temp doesn't drop an alarm sounds and the box is sealed.
ReplyDeleteWould need to know about the physics of lithium ion battery explosions to determine if the box can be made strong enough at a reasonable cost to contain it.
Neither of us have any intention of buying any lithium battery powered toys.
No cooling will help a runaway Li battery. And they can run away just sitting there with a partial or full charge. Once that reaction starts, usually because the dielectric film between the Li sheets breaks down due to thermal or mechanical stress, you get a short between layers. This quickly (milliseconds) breaks down more dielectric, allowing more shorting, and then you get to the point where the Li melts and starts to burn. At that point it is "stand back Gertrude" cause that battery is gonna go up. You can slow it down, or you can speed it up, but until it is slag, it's gonna happen. Oh, and water and air both fuel the fire because room temp Li reacts with both, and hot Li reacts to the point where a lay person can't tell the difference between that and an explosion. Oh, and one of the reaction products with water is hydrogen...which also joins the party as fuel...and your water you sprayed on the fire is now a caustic mix of lithium hydroxide, which although not as aggressive as lye or potash is similar enough that it takes special measures to neutralize it.
ReplyDeleteMy thought was that active cooling during charging would reduce the 'flexing' of the internal structure and reduce the fatigue failures inducing shorts.
DeleteRight now is the time to get laws on the books banning the storage or parking of EV within or under an inhabited building.
If they are having these problems with 1%-2% of the vehicles now electric, what happens when it's 10%, 20%... etc.
So if I get this right, one pokey-pokey from,say, a black-tip projectile in an EV battery pack should cause an offending vehicle to both catch fire AND change shape?
DeleteAsking for myself...
Electric bikes are becoming very popular and I bet most get parked in a structure both for security and to keep the battery from freezing in cold weather. Anecdotally, it appears most of the bike “ cook offs” come from the cheaper bikes. I see them advertised for $300 or so. “Townie” electric bikes are $1200-1500 and they claim no problems with burning batteries. I have townie pedal bikes and they start at $700-800.
ReplyDeleteEven 'high end' bike batteries are susceptible to damage, internal and hidden.
Delete