Can I feed DC to L2 charging port

(I cannot find previous discussion on this. Please point me to the post if the tree had been barked on before.)
Can I feed a 120v or even 220V DC to L2 charging port, via a EVSE (e.g. OpenEVSE) of course? Can Leaf's onboard charger handle DC input? Does the charging circuit, e.g. current sensing, requires AC?

best regards

We need someone with a wrecked Leaf to try it.

Please don't try this.

Thank you.

TonyWilliams said:

Please don't try this.
Thank you.

Click to expand...

It doesn't seem such a silly question to me; 220VDC is a lower voltage than the inlet sees from a normal L2 EVSE; the issue is whether the power converter depends on working from AC only somehow. A look at authoritative specs or maybe a schematic would settle it..

Levenkay said:

TonyWilliams said:

Please don't try this.
Thank you.

Click to expand...

It doesn't seem such a silly question to me; 220VDC is a lower voltage than the inlet sees from a normal L2 EVSE; the issue is whether the power converter depends on working from AC only somehow. A look at authoritative specs or maybe a schematic would settle it..

Click to expand...

Rarely does an AC/DC converter truly depend on working from AC only. Typically, the first thing done is to rectify the AC into DC anyway. That means passing the positive voltage and inverting the negative. Most rectifiers would work fine with a DC input - they would simply only ever activate one leg (presumably the positive one, but if you invert the DC input, it would be the negative leg). What I'm not sure about is whether exercising one leg would cause it to overheat and fail that way.

All that said, I'm not sure why anyone would want to do what the OP asked. Are there pockets of DC grids in the world? Or is this for some sort of off-grid application?

soldcake said:

(I cannot find previous discussion on this. Please point me to the post if the tree had been barked on before.)
Can I feed a 120v or even 220V DC to L2 charging port, via a EVSE (e.g. OpenEVSE) of course? Can Leaf's onboard charger handle DC input? Does the charging circuit, e.g. current sensing, requires AC?

best regards

Click to expand...

I assume you are trying to use direct DC via Solar, is this correct? Regardless of AC or DC you can't do this without a battery bank in parallel.

The diode rectifier would be happy with DC, but power factor correction (PFC) stage might have a problem with DC if it relies on AC current transformer to measure input current, or if small AC transformer is used to provide startup power or AC voltage monitoring. We would have to look at charger schematic or reverse engineer one from wrecked Leaf to be sure. Another pitfall might be the software in charger controller that expects AC and might shut down the charger on DC input.

You can find the overview schema and a fairly good description of the electronics in the appropriate manual from this url;

https://ownersmanuals2.com/make/nissan/leaf-2012-372

Actually, an interesting question - especially if you are planning on using PV panels with a high voltage battery bank and a MPPT charge controller for "opportunity" charging. I'm actually installing a level II system based on the limitations of my 3.3kw charger with a 208 VAC inverter - not very efficient, but I have all the stuff and want to try. Direct DC using a (smallish?) high voltage battery bank would potentially be more efficient. I believe you will need some type of (Leaf) charge controller with ampere control to prevent "draining" the battery bank or better yet figure a way to have the Leaf's installed charger to do that! My guess is that the Leaf charger will balk at pure DC though - not an electronics wizard, so don't really know.

Marktm said:

You can find the overview schema and a fairly good description of the electronics in the appropriate manual from this url;

Click to expand...

No good. Service manuals do not have circuit level schematics of parts. Makes sense, technicians do not fix parts, they replace them.

AntronX said:

No good. Service manuals do not have circuit level schematics of parts. Makes sense, technicians do not fix parts, they replace them.

Click to expand...

Agreed - I faced the same in trying to understand the DC/DC converter - nothing but "black boxes". At least they gave a good overview of the charger sections - to at least know what you are dealing with. I suspect the topology of each section is fairly conventional. Again, not an electronics wizard to be able "reverse engineer".