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Stevo
04 September 2017, 1138
With all the talk about N.Korea nukes... I understand an EMP weapon can take out an entire country's grid...
but what effect would such a weapon have on Li cells? Our ev's controllers would probably get fried, but what about other components, such as motors and battery packs? Would our ev's be salvageable? Would our ev's be easier to repair after such an event compared to ICE tech?

nedfunnell
04 September 2017, 1235
With my limited remembrance of college physics:

An EMP is a short bursr of extra-strong electromagnetic energy. It can disrupt the operation of or damage unshielded or poorly shielded electronics by putting electrons where they don't belong in circuits. I don't think EMPs would affect our large Li-ion cells, since they are pretty darn tolerant of current moving through them. Controllers are a different situation. I'm not sure if the aluminum cases present on most controllers would provide any or adequate shielding- they might, but the unshielded wiring connected to them would probably collect enough energy from the EMP and deliver it straight to the sensitive component inside to mean it doesn't matter. Suddenly getting a burst of who knows how much voltage and current at an odd frequency on the throttle wires is probably enough to fry any controller. I think the high-power wires would be OK- the FETs or IGBTs, again, are made to handle high current. I don't know what kind of voltage might be fed to them by the power wires in an EMP situation- that's a hugely variable situation and you'd have to test each individual build on test rig like the ATLAS-1 or simulate it in a complex computer simulation.

I think you'd be right to think that any electonics would need to be replaced: controller, maybe throttles, BMSes, instrumentation panels, etc- would probably all be gone. I think motors (except hall sensors/encoders for AC motors) and batteries would be OK though. It's probably a crapshoot compared to ICE vehicles, which are also full of electronics and unshielded wiring.

Best choice? Move to a rural place that North Korea doesn't want to nuke. :cool: If not... park your bike in a faraday cage and hope the North Koreans don't get angry while you're out on a ride.