cyclist-runs-for-his-life-after-electric-bike-explodes-in-a-
- Thread starter Boyntonstu
- Start date
DAND214
10 MW
Sure glad it was those safe 18650 cells. Just think what would of happened if it was LiPo. A lot of flames but no exploding metal cans. So which one is really better? Use a trusted 18650 to ignore them till they blow or use Hobby LiPo and watch what is going on all the time?
Don't know, have to see what the verdict is later.
Dan
Don't know, have to see what the verdict is later.
Dan
The fingers
10 TW
Matador
100 kW
- Joined
- Jun 29, 2016
- Messages
- 1,045
LOL...
Glad is was 18650 and not a tank full of gasoline that could explode and burn the rider...
THis sounds like BS propaganda.... Shrapnel ??? really ??? Yeah right. This is no grenade. 18650 have vents for thermal runway. All I see is a bit of burnt residue on those 18650.
Sure fire can happen, but this article is as credible as Donald Trump.
Now they will try to ban DIY kits you can have for a few hundreds and
only limit eBikes use to 6000 dollars 200W turn-key eBikes ? Is this the goal of this propaganda? . Control the market?? Impose crappy slow ebikes for outrageous prices under the pretex that DIY kit kill people ???
I couldn't help but laugh... Seem like the author doesn't know too much on eBikes and likes to exaggerate. It could go one step further in this delirium, exploding 18650, sending radioactive lithium isotope in the air we breath...blabla
The problem here is not the DIY kit. It's a poor quality battery that's not suited for the system. I'm sure I could find a way to make a Bosch or Yamaha burst into flames too, whith enough time.
Glad is was 18650 and not a tank full of gasoline that could explode and burn the rider...
THis sounds like BS propaganda.... Shrapnel ??? really ??? Yeah right. This is no grenade. 18650 have vents for thermal runway. All I see is a bit of burnt residue on those 18650.
Sure fire can happen, but this article is as credible as Donald Trump.
Now they will try to ban DIY kits you can have for a few hundreds and
only limit eBikes use to 6000 dollars 200W turn-key eBikes ? Is this the goal of this propaganda? . Control the market?? Impose crappy slow ebikes for outrageous prices under the pretex that DIY kit kill people ???
I couldn't help but laugh... Seem like the author doesn't know too much on eBikes and likes to exaggerate. It could go one step further in this delirium, exploding 18650, sending radioactive lithium isotope in the air we breath...blabla
The problem here is not the DIY kit. It's a poor quality battery that's not suited for the system. I'm sure I could find a way to make a Bosch or Yamaha burst into flames too, whith enough time.
e-beach
10 MW
DAND214 said:
Ummmm. I don't get it. Are you being facetious? It appears to be 18650 cells that burned in this case. Or at least the picture seems to confirm it. It looks to me to be a 18650 fire. This was a bad fire. No time for joking.
dogman dan
1 PW
That one looked to me like he had a smaller battery in a bag on the frame, taped on, or something like that. Mechanical damage short would be the assumption here I think. Mechanical short seems to be how to make it blow on you mid ride.
Shrapnel,, hell yes, there was parts of 18650 cans all over my garage after my fire. Only about 1/4 of the cans were left near or on the bike after it burned. These things don't vent gently when in thermal runaway. they blow the ends off. My fire sounded exactly like a box of bullets thrown in the fire. That's what woke up my wife.
Shrapnel,, hell yes, there was parts of 18650 cans all over my garage after my fire. Only about 1/4 of the cans were left near or on the bike after it burned. These things don't vent gently when in thermal runaway. they blow the ends off. My fire sounded exactly like a box of bullets thrown in the fire. That's what woke up my wife.
Hummina Shadeeba
1 MW
If a better cover was put on cells than that thin plastic that would probably stop a lot of problems with homemade packs. there's surely some material just as thin and cheap and much more abrasion resistant. any cells beside each other not in parallel that are subject to vibrations are an eventuality waiting to happen.
Boyntonstu
10 kW
dogman dan said:
Did you determine why it happened?
Were they being charged and if so at what rate?
DAND214
10 MW
Yes and no. All I was saying is,that any battery can burn. We don't need any battery fires. All they cause is more concern about batteries, being a ebike or a Tesla. Maybe it's all bad air from the oil companies, what ever it is we don't need it.e-beach said:
Dan
Hummina Shadeeba
1 MW
Every manufacturer's spec sheet I've seen for Li-ion includes a shorting test to see if they go up in flames and according to the manufacturer they all pass
https://eu.nkon.nl/sk/k/30q.pdf
https://eu.nkon.nl/sk/k/30q.pdf
It would be nice to know what kind of battery it was and who made it. The fire safety of lithium batteries is a big issue but there are things that can be done to really minimize it.
spiros
10 W
This kind of explosions and fires are a characteristic of new type of cells with high Ah and C rates or have been occurring also with the older cells like Samsung 29E?
Because if older cells are safer I would prefer an older type of battery for all day commuting and some Lipo for playing hard.
Because if older cells are safer I would prefer an older type of battery for all day commuting and some Lipo for playing hard.
Sure, in a single cell.Hummina Shadeeba said:
Parallel a bunch of cells and then pack them in close with each other so heat cannot escape, and the shorted cell then has to absorb the energy of *all* of the cells paralleled with it. Then it has to radiate that heat out thru the rest of the cells around it, as well as the casing.
If the heat gets past a certain point, especially if it actually reaches the flame point, the cells next to it will go runaway thermal, and then the next, etc etc.
That's one way you get a fire like the one on this bike (or Dogman's, etc).
liveforphysics
100 TW
Hummina Shadeeba said:
It matters very little what the cell itself being shorted causes, if the cracked welds are causing glowing bussing or chaffed balance tap leads glowing red or corrosion induced current path heating.
18650 fires, including in "hoverboards" and more consumer products are rarely from a bad cell or cell defects.
dogman dan
1 PW
https://endless-sphere.com/forums/viewtopic.php?f=1&t=87975
There is the thread on my fire. My best guess, and I do mean guess, is that deep discharge pushed a cell into an internal short condition, then when charging, AW hits it on the head, the shorted cell gets nice and hot since its paralleled to the others, and discharges all of them to the point of starting a thermal run away. the fire happened just about when the pack got full. Relatively slow charge, 5 amps for 20 ah pack.
So while I totally agree with Luke about the cause of most fires,, I just had to be the lucky one. There could have been physical damage to my pack, but I have no way to know it, and no reason to suspect it, unlike the hoverboards that get thrown against the wall as the rider learns to use it.
I still believe most of you are safe, like I said, I just got to be the lucky one to hit the incredible high odds. But you are not safe, if you carry the battery unprotected, like I suspect this guy did. I'm betting on the duct tape in his case. I'm thinking he did something that caused a short, or perhaps the pack was built cheap, and could easily short at the + terminals to the - case. That also, could have been the case with my pack. But because it blew on charging, I tend to suspect internal short caused the cascade of events that led to a fire.
There is the thread on my fire. My best guess, and I do mean guess, is that deep discharge pushed a cell into an internal short condition, then when charging, AW hits it on the head, the shorted cell gets nice and hot since its paralleled to the others, and discharges all of them to the point of starting a thermal run away. the fire happened just about when the pack got full. Relatively slow charge, 5 amps for 20 ah pack.
So while I totally agree with Luke about the cause of most fires,, I just had to be the lucky one. There could have been physical damage to my pack, but I have no way to know it, and no reason to suspect it, unlike the hoverboards that get thrown against the wall as the rider learns to use it.
I still believe most of you are safe, like I said, I just got to be the lucky one to hit the incredible high odds. But you are not safe, if you carry the battery unprotected, like I suspect this guy did. I'm betting on the duct tape in his case. I'm thinking he did something that caused a short, or perhaps the pack was built cheap, and could easily short at the + terminals to the - case. That also, could have been the case with my pack. But because it blew on charging, I tend to suspect internal short caused the cascade of events that led to a fire.
