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We're Charging Our Cars Wrong

spectrum.ieee.org

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Re: We're Charging Our Cars Wrong

#3
tl;dr existing galvanic isolation in fast chargers is very costly (~60% of capital cost) and delaying deployment of unsubsidized EV charging infrastructure; the authors think it can be replaced safely and cost-effectively with a second ground wire and some logic to detect/verify grounding.

Re: We're Charging Our Cars Wrong

#4
A big issue I see with this is that it would necessitate a new fast charging standard, which (due to the extra ground connection) could not be backwards compatible with any existing fast charging standard - rendering it useless for the 40 million electric cars already on the roads worldwide.

Re: We're Charging Our Cars Wrong

#7
The argument sounds kind of persuasive to a layman (even one that did a little bit of EE a while back), but my gut says there would be no need to write this article if there weren't regulations or other engineering traditions that decided galvanic isolation is necessary for safety.

I guess the difference is galvanic isolation is physically (i.e. passively) fail safe, while ground detection is an active safety measure? You can always put in two ground wires in the current system too...

Is there some way for the ground wire to have a signal in it even if it were broken (via EMF)? Can the chip fail in an unsafe way?

Re: We're Charging Our Cars Wrong

#8

A big issue I see with this is that it would necessitate a new fast charging standard, which (due to the extra ground connection) could not be backwards compatible with any existing fast charging standard - rendering it useless for the 40 million electric cars already on the roads worldwide.

[deleted]

Re: We're Charging Our Cars Wrong

#9
Lightning strikes...how do EVs currently guard against it?

- With galvanic isolation baked directly into onboard charger, I'm thinking worst case outcome is charging infra and isolation link get fried, but that really expensive EV battery remains safe.

- Without galvanic isolation, battery goes...boom? Hopefully without you or your family waiting inside the vehicle under some false pretense of safety.

Re: We're Charging Our Cars Wrong

#10
It would be nice if instead of the fast charging problem the focus would be shifted to standardized battery packs, that can be field replaced. I don't really want to own 50-100kwh battery. I just want to use the charge in it and happy to pay for that.
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