> "A new battery module isolation loss alarm has been added."<p>This is the worst fault possible in an EV 101 scenario right here (touch metal -> instant death), so I'm surprised that with all Tesla's experience, they didn't consider an isolation leak as a serious fault. And I'm surprised that they allow the battery monitoring system to be disabled during servicing, especially the IMD (insulation monitoring device).
An extract from the summary page suggests a few things went wrong, but it seems like the fire was caused by liquid and electricity mixing:<p>> ESV found a Megapack cooling system leak caused a short circuit resulting in overheating that led to a fire in a nearby battery compartment, which consequently damaged two Megapacks.<p>> There were further contributory factors with the Megapack in question being switched into an off-line service mode, resulting in the protection systems being inactive.<p>> A 24-hour delay in connecting the batteries to the supervisory control and data acquisition (SCADA) system also meant there was no active monitoring of the Megapack alarms.
Reading this it’s a classic systems failure: multiple defensive barriers gone wrong through poor safety planning. It’s reminiscent of the Victorian ESSO gas plant accident <a href="https://en.wikipedia.org/wiki/Esso_Longford_gas_explosion" rel="nofollow">https://en.wikipedia.org/wiki/Esso_Longford_gas_explosion</a>
for people who might say 'oh, but these batteries are so dangerous!'<p>How many cooling system leaks (radiator+water pump related plumbing) result in vehicle engine fires per year?<p>I imagine the largest insurance companies have reasonably good data on this as a cause of total-loss of a vehicle.<p>How many times have you seen in person, or seen a photo of a burned out RV that somebody pushed too hard up a mountain pass without keeping an eye on the engine temperature?
> There were further contributory factors with the Megapack in question being switched into an off-line service mode, resulting in the protection systems being inactive.<p>A short in an offline device? That seems weird.<p>> A 24-hour delay in connecting the batteries to the supervisory control and data acquisition (SCADA) system also meant there was no active monitoring of the Megapack alarms.<p>So a new pack was installed and connected but not monitored? What is the rationale behind that? Failures shouldn’t happen to new devices?
<i>> Shorter connection times to the SCADA system to help alert Tesla with specific alarms.</i><p>Interesting that even after installation Tesla are still involved in operationally managing the megapacks.
One advantage of LFP batteries is that they can survive much higher temperatures without degradation.<p>If you can make battery packs air cooled, that's a big, big weight saver.