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Tesla DC V2G with a CHAdeMO adaptor

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willow_hiller

Well-Known Member
Apr 3, 2019
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31,089
Maryland
Amid all the news that bidirectional charging is not possible via the in-built AC to DC rectifier circuit on the Tesla charging board, a lot of people have overlooked the fact that most existing V2G implementations are done DC to DC with an inverter installed outside of the vehicle (on the home).

I know in theory, the Supercharging circuit uses transistors where the rectifier uses diodes, so it's possible that power could flow in both directions DC to DC. In fact, there have been posts on this forum saying that it has already been done with use of a CHAdeMO adaptor M3 and MY bidirectional Charging. by @Picasso

Has anyone tried this and documented it with pictures or video? In theory, would it just be a case of installing a CHAdeMO DC bidirectional charger on your home like the Quasar and plugging a CHAdeMO adaptor into the car? Would you need to first spoof a Supercharging handshake to open the DC connection before attempting to draw power out? How does the car's software handle draws on the battery when it thinks it should be Supercharging?
 
Maybe Tesla software engineers are as dumb as a bag of bricks?

Tesla will shutoff the charge port if the electrical flow is even slightly irregular.

It doesn't matter that the hardware is capable if it is software locked.
 
Maybe Tesla engineers are as dumb as a bag of bricks?

Tesla will shutoff the charge port if the electrical flow is even slightly irregular.

They can enable this feature in the future, or you can use some other method to get power from the battery.

Enabling software is one thing; the real major hurdle to V2G right now is legislation. All Nissan Leafs explicitly have bidirectional chargers and utilities are only now getting around to pilot programs.

I'm more curious about the feasibility of Tesla V2G right now, especially with some reported instances of it already. I'm sure Tesla will eventually have some sort of official V2G solution.
 
The Model 3 onboard charger power bridge is already bidirectional. The only thing needed that I am aware of is software and maybe some protective hardware.

‘From what I have read is that Tesla’s concern is battery warranty if battery is used for other than normal driving. Depending on the frequency and capacity of usage of V2G it could reduce the life expectancy of the battery.
 
The Model 3 onboard charger power bridge is already bidirectional. The only thing needed that I am aware of is software and maybe some protective hardware.

This is only partially true. It was shown recently that the AC to DC onboard charger uses unidirectional diodes instead of transistors. Only the DC to DC bridge uses transistors that are capable of a bidirectional flow. Hence this thread :)

Source: Viral article on Tesla bidirectional AC charging is “debunked”