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#### cricketo

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I did some Googling, in addition to what's said above, there is a claim that the minimum advertisement supported for J1772 is 6A, which at 240VAC is still pretty substantial 1.5kW.

#### remy_martian

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Oops...I regularly run 32A

#### cricketo

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I have noticed that you post a lot of shit, perhaps you need to improve your reading comprehension before you post MINIMUM. The OP wants to throttle towards MINIMUM draw, not towards maximum.

#### remy_martian

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Dude - I'm dealing with health issues, so cut me some slack. Yes, I missed that word.

The Bolt has a 0.5kW "keep alive" for the charger connection, so I need to double check you on that MINIMUM current of 6A 🤓

#### remy_martian

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Yup...6 amp minimum maximum the car can pull

#### cricketo

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This is the reasoning :

The SAE defines the ampacity value to be derived by a formula based on the 1 ms full cycle (of the 1 kHz signal) with the maximum continuous ampere rating being 0.6 A per 10 µs up to 850 µs (with the lowest 100 µs × 0.6 A = 6 A).

#### remy_martian

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The question then becomes: what's the lowest voltage the onboard charger can take?

Edit: *input voltage

#### cricketo

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I imagine 90-100VAC is the minumum if it combines L1 and L2 in a single unit, but dropping the voltage on the fly is probably even more difficult.

I think a buffer battery like was suggested earlier is a much more straightforward path that is guaranteed to work, as opposed to trying to fish out support for corner cases out of the spec. I'd go with a normal MPPT charge controller, 6-8kWh battery (LFP or possibly LTO) and a battery inverter with load shedding.

#### remy_martian

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Need to run 5% duty cycle on the pilot - at that point, what's the min vehicle charge current using J2931 digital comms?

#### cricketo

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Just the math alone should put it at 3A I guess. But given it's outside of the range established by the standard, the results can be unpredictable - charger could respect that, ignore it and stick to known min of 6A, treat it as a failure condition or... crank it out to the max because the guy who wrote the firmware left a bug in there!

#### remy_martian

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No no....nobody said there wuz gunna be math 😂

5% kicks the interface into a digital comms mode using the so-far-a-total-mystery J2931 standard.

#### cricketo

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No no....nobody said there wuz gunna be math 😂

5% kicks the interface into a digital comms mode using the so-far-a-total-mystery J2931 standard.
I missed that part! Well, I guess OP will investigate and let us know how that turned out

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