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Comment by sp332 | Hacker News Reader

NACS doesn't have a standard for vehicle-to-home (or vehicle-to-grid) charging. When they opened up the standard, Tesla said that it was allowed, but they didn't specify any standard way to do it. So it might happen, but there's potential for incompatibilities between car manufacturers and charging systems.

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Chademo supports bidirectional charging. But bidirectional charging means you basically need a DC fast charger, and those are like $10k. (Hard to find an actual number online besides Alibaba… it’s always an “inquire for price” email quote button… which tells you it’s gonna be like $10k.)

By far the easiest way to pull power from an EV is from the 12V subsystem. The DC-DC converter for EVs usually is like 2kW, so it’s substantial power. …although older Teslas make it hard to access this much as I think they were worried about people abusing free Supercharging… there’s a 12 Amp fuse for the cigarette lighter port and a 50 Amp fuse for the jump posts accessible in the front, even 12V and 12A is enough to power a fridge for weeks if you buffer it through one of those “solar generator” things. That’s what I did during a recent power outage for my 2013 Model S. My 2013 Nissan Leaf has a 12V battery that’s easier to access, and I could pull about 1.2kW from that (have to keep the car on so the high voltage battery is connected to the DC-DC converter, keeping the 12V subsystem charged) using a couple inverters.

Cheapest Chademo bidirectional V2H equipment for home in Japan costs 500k JPY https://etex.jpn.com/info/v2hhojyo/ https://www.nichicon.co.jp/products/v2h/about/specs/

What's the price of the inverter on the other end? Installation?

This "EV power station" integrates inverter. Don't need additional inverter for other end. Installation is 300k from prev article, maybe discounted a bit when I get real quote.

As Tesla moves to replace the 12 volt subsystem with 48 volts, it would seem even more plausible to do V2L by routing outgoing power through the 48 volt system.

The Ford F150 Lightning does V2L through the 9.6kW of on-board inverters. Fairly sure it's not capable of sending that back through J1772 / CCS2 unless I'm mistaken?

The F150 Lightning does V2L via the CCS port. It's supported, just the only car that I'm aware of that does this is the F150 Lightning.

Ioniq 5 does it too

Ah right, via the weird dongle they have. It's not integrated into a home backup setup like the F150L, though.

Adopting NACS won't prevent Ford from supporting vehicle-to-grid, since they build both the truck and the charger, and the connector itself doesn't care what direction the electrons are flowing.

But it would be really nice if it was standardized for interoperability reasons.

The Ford F150 Lightning does V2L through the 9.6kW of on-board inverters. Fairly sure it's not capable of sending that back through J1772 / CCS2 unless I'm mistaken?

To do power-to-grid you simply need to connect to the car's HVDC bus and tell the car "please don't panic if you see current flowing out, not in".

NACS handles the HVDC connection just fine, and simply lacks the second part. But it's just software, it can be standardized later.

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