WetEV
Well-known member
Notice what happens after the fireman starts spraying water, at about 1:20
I'm guessing your concern is about the possible reaction of lithium to water, but https://www.nfpa.org/-/media/Files/Training/AFV/Emergency-Response-Guides/Chevrolet/Chevrolet-Bolt-EV-2017-2019-QRG.ashx says to use water.goldbrick said:Indeed. 2 things that struck me is 1) how casual they were at first approaching the car with all the smoke coming out of it and 2) water??? :shock: on a Li fire?
The NHTSA guidance makes it sound much more ominous than the specific issue described at Chevy's recall site.cwerdna said:The guidance at https://www.nhtsa.gov/press-releases/consumer-alert-chevrolet-bolt-recall-fire-risk differs somewhat from https://my.chevrolet.com/how-to-support/safety/boltevrecall.
DougWantsALeaf said:I just hope this doesn't hurt their sales too much, as they were just gathering steam. It doesn't look like the issue is in the new packs.
DougWantsALeaf said:I just hope this doesn't hurt their sales too much, as they were just gathering steam. It doesn't look like the issue is in the new packs.
That seems unlikely to me - what is the max pack/cell voltage that GM charges to?GetOffYourGas said:One of the theories that I've heard is that as weaker cells age, their internal resistance increases. The BMS software may not account for this properly, causing those weak cells to overcharge, overheat, and start a fire.
I'm surprised that this isn't the default setting of the car - both to improve battery life and efficiency so that you have regen available at the start of every drive. It does also improve safety - the higher the voltage of the cell, the more energy there is to be released in the event of a cell failure.GetOffYourGas said:I hope GM gets to the bottom of this, but I'm not overly concerned. The recall's solution is to limit the SoC to 90%, which I already do via Hilltop Reserve.
DaveEV said:That seems unlikely to me - what is the max pack/cell voltage that GM charges to?GetOffYourGas said:One of the theories that I've heard is that as weaker cells age, their internal resistance increases. The BMS software may not account for this properly, causing those weak cells to overcharge, overheat, and start a fire.
Monitoring cell voltages and ensuring that bad things don't happen is the #1 job of the BMS - whether that's monitoring for high voltages during charging, or low voltages when discharging.
That is not the recall solution, it is the 'what to do until we figure out the problem and issue a recall.'GetOffYourGas said:The recall's solution is to limit the SoC to 90%, which I already do via Hilltop Reserve.
Correct on the first point.SageBrush said:That is not the recall solution, it is the 'what to do until we figure out the problem and issue a recall.'
Answer me this: if GM has not figured out the cause of the fires yet, why are you confident that the 90% SoC charge will protect you ?
It would be quite the firmware bug that allows cells to get so far out of balance to allow a cell to spontaneously combust. It would take charging the cell well above 4.2V.GetOffYourGas said:I'm not sure I follow you. A proper BMS will monitor cell voltages and ensure that bad things don't happen. So why is it unlikely that an improperly programmed BMS could cause this problem? It reads to me like you support this theory more than presenting an alternative. Unless it is the question of aging that you disagree with? But as cells age, those differences could widen, making the BMS ever more important over time. It has to assure that weaker cells don't overcharge or overheat.
SageBrush said:That is not the recall solution, it is the 'what to do until we figure out the problem and issue a recall.'GetOffYourGas said:The recall's solution is to limit the SoC to 90%, which I already do via Hilltop Reserve.
Answer me this: if GM has not figured out the cause of the fires yet, why are you confident that the 90% SoC charge will protect you ?
Funny.GetOffYourGas said:I am satisfied with the current level of risk I have with the car set to Hilltop Reserve and parked outside.
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