Bike in what seems to be a shared hallway, and so a shared escape route. Shouldn't be there.Another conversion fire
Converted electric bike caused fatal Coventry fire
Investigators focus on a pedal bike converted into an electric model stored in a property's hallway.www.bbc.com
The state of data about ebike fires is so pathetic that its hard to make out what really causes fire. All that one hears about is charging, but there are several incidents of fire while riding.Becoming quite a risk, this subject. There's now a significant trend of bike shops being denied insurance because somehow the insurers have come to the idea that an e-bike is almost always a risk, when in fact all of the risk is coming from things that are not, in fact, e-bikes: https://www.cyclingelectric.com/news/call-for-government-to-up-pace-on-dangerous-kit-imports-or-face-existential-risk-to-cycling-industry
"The product presents a risk of fire as it has been identified that when the electric bike is being charged, it is possible for the lithium-ion batteries to go into failure mode, potentially leading to a thermal runaway and fire."
I don't quite understand logic behind this decision. Between November 15 and April 15 there is a risk of fire and between April 16 and November 14 there is no risk of fire?The decision means that all e-bikes and e-scooters will be banned from November 15 to April 15
Winters here are very different from summers. Roads are slushy with snow and salted, and the thinking appears to be that salt and water leads to more chances of electrical shorts. Unfortunately whatever data is out there on battery fires is so incomplete and of poor quality to make any conclusions. The only largish ebike battery fire in a TTC subway car happened on Dec 31, 2023 --- one data point for winter, zero for summer!I don't quite understand logic behind this decision. Between November 15 and April 15 there is a risk of fire and between April 16 and November 14 there is no risk of fire?
Yes. A decent one will cut off charging when cells are at designed max, DIY battery builders know how that works, or they should.Shouldn't BMS protect battery?
Looking at the datasheet for the LG MH1 cells in my battery...Yes. A decent one will cut off charging when cells are at designed max, DIY battery builders know how that works, or they should.
Even so, quality bare cells can take overvoltage. From the Lishen 21700 cell data sheet. You can short circuit them or overcharge to 6.3V.
9.1. External Short-circuiting Test at 25 ºC
Cell fully charged per 7.1.1, is to be short circuited by connecting the positive (+) and negative (-) terminals
with a total external resistance of less than 50mohm. Stop the test when the cell voltage falls below 0.1V
and the cell case temperature has returned to a value within 10 ºC of the original testing temperature.
Criteria: No Explosion, No Fire
9.2. Overcharge Test
Cell fully charged per 7.1.1, is to be overcharged with 1.0C to 6.3V while tapering the charge current.
Charging is continued for 7 hours.Monitoring change of cell temperature during testing. Stop the test when
cell temperature decays to room temperature.
Criteria: No Explosion, No Fire
Sure, if they put in crap cells where the batteries can't pass hazmat shipping rules, overcharging will burn them up if the BMS fails,
And this goes back to the first video in this thread, where the Grin guy says good cells make for the safer batteries;.
Are these the cells with built in protection? Almost a bms per cell. So a short would not be a Real short?Yes. A decent one will cut off charging when cells are at designed max, DIY battery builders know how that works, or they should.
Even so, quality bare cells can take overvoltage. From the Lishen 21700 cell data sheet. You can short circuit them or overcharge to 6.3V.
9.1. External Short-circuiting Test at 25 ºC
Cell fully charged per 7.1.1, is to be short circuited by connecting the positive (+) and negative (-) terminals
with a total external resistance of less than 50mohm. Stop the test when the cell voltage falls below 0.1V
and the cell case temperature has returned to a value within 10 ºC of the original testing temperature.
Criteria: No Explosion, No Fire
9.2. Overcharge Test
Cell fully charged per 7.1.1, is to be overcharged with 1.0C to 6.3V while tapering the charge current.
Charging is continued for 7 hours.Monitoring change of cell temperature during testing. Stop the test when
cell temperature decays to room temperature.
Criteria: No Explosion, No Fire
Sure, if they put in crap cells where the batteries can't pass hazmat shipping rules, overcharging will burn them up if the BMS fails,
And this goes back to the first video in this thread, where the Grin guy says good cells make for the safer batteries;.