Connecting a V2L car to a house as a battery.

[SimonS]

V2G in the UK is now possible if you have the right car and charger.... Octopus Power Pack: the UK’s first Vehicle-to-Grid tariff

 

[DaevM]

Great, just swapping my ChadeMo vehicle for CCS... as ever, perfect timing ...if I read it right. Don't think the ChadeMo vehicle can discharge anyway, so no great loss

 

[AusAeroDave]

Could this be used to feed a grid tie inverter with DC voltage from the Vehicle when connected to an input string?

1230W 220VAC to 0-410VDC power supply

 

[deanhalllincoln]

Here you go using V2L to supply an entire house.

 

[DaevM]

Here you go using V2L to supply an entire house.

Is this your channel?

 

[AusAeroDave]

The problem with this set-up is it's one or the other. Either the whole house is connected to the car (a limited 3kW supply) or the grid.

There has to be a way of connecting the V2L to the house and if demand exceeds the 3kW to simultaneously take from the grid.

The only way I can see to do that is through a hybrid grid connected inverter.

 

[AusAeroDave]

I think I've sorted it using the following:

• 1230W Advanced variable adjustable 220 VAC 0-6A - 0-410VDC switching mode dc power supply
• MPPT Pure Sine Wave Grid Tie Inverter 2000W With Limiter
• Dedicated 15A Socket to Dedicated 15A Circuit (Not to be used for any other purpose)

220 VAC from the vehicle gets converted to 90V/6A to the plug in grid tied inverter, this is connected to the Fuse Box via a dedicated 15A circuit and load limiter so the inverter will never export to the grid. This should provide power for an average home where overnight use is limited to a fridge and a freezer turning on and off intermittently and a few lights/TV etc... If any extra power is required, it's provided by the grid.

Inspiration came from Off Grid Garage YouTube Channel's video HERE

 

[Coulomb]

I think I've sorted it using the following:

It seems like there's a lot of losses involved:

• Charging losses before energy gets into the car's battery
• Battery inefficiency (discharges at a lower voltage than it charges)
• Losses in the V2L DC-AC converter
• Losses in the DC-AC power supply
• Losses in the grid tie inverter
• Some small additional losses in the various cables.

Also, since it's a grid tie inverter, it won't push power to grid wiring when the grid goes out (good), but that means it won't work just when you need it most (i.e. you're in a blackout). You could then transfer loads to the V2L directly, but not via that 15 A socket because when the grid comes back, the V2L and grid will be out of sync, and boom.

If it's a "hybrid" inverter that has an essential loads output that works with no AC-in (I don't know if such exist), then you could connect the essentials output to special sockets in the house. But then you need a transfer switch, or you have to switch essential loads manually in the case of a blackout.

It gets crazy complex quickly.

 

[AusAeroDave]

All very true, the losses; considering it's a 60kW battery, I can easily live with.

We haven't had a loss of mains power in over 10 years so back up doesn't concern me either.

If we ever do have a power loss, disconnect from V2H and connect the fridges directly to the car. No big issue there.

In all - this should work and negate the pitfalls of a Plug-in GTI due to the dedicated circuit.
It's fairly seamless once set up is complete and provides power to the whole house up to a load limit.

 

[Coulomb]

What's the reason for the 90V limit from the power supply? That limits you to under 540W.

If it's a limit of the inverter's PV input, you could probably find a better match of power supply or inverter to get more peak power throughput.

 

[johnb80]

I have a conventional solar PV - Inverter and battery system installed. Adding V2L to add power is easily achieved by connecting a 3kW battery charger to the V2L with its output connected to the LiFEP04 batteries. It all works seamlessly and is simple to do. The cost of the charger was circa £50.

 

[AusAeroDave]

That 90VDC input to the inverter is limited by the inverter used as an example, but I'm sure there are Plug-In inverters capable of more. Just need to do more research.
I'm stoked by the possibilities of this. Should have it up and running by September/October this year.

 

[johnb80]

That 90VDC input to the inverter is limited by the inverter used as an example, but I'm sure there are Plug-In inverters capable of more. Just need to do more research.
I'm stoked by the possibilities of this. Should have it up and running by September/October this year.

Be careful with your proposed connection toi the inverter being via a 'widow maker' plug (the exposed pins can be live).

 

[Barrie]

I have a conventional solar PV - Inverter and battery system installed. Adding V2L to add power is easily achieved by connecting a 3kW battery charger to the V2L with it's output connected to the LiFEP04 batteries. It all works seamlessly and is simple to do. The cost of the charger was circa £50.

Can I ask which battery charger you are using please ?

 

[AusAeroDave]

Be careful with your proposed connection to the inverter being via a 'widow maker' plug (the exposed pins can be live).

There should not be any exposed pins. V2L to DC Converter via CCS2 to Power cable.
DC Converter to GTI - Wired.
GTI to 15A Socket - Continually plugged in.

The only thing that would ever get disconnected is the CCS2 at the vehicle.

 

[Coulomb]

GTI to 15A Socket - Continually plugged in.

Also, it's a grid tie inverter. It won't output power until it has seen the grid stable for one minute. If it is ever unplugged, it should detect the lack of load immediately and stop the power.

 

[johnb80]

Can I ask which battery charger you are using please ?

Its a power supply I stripped out of a datacentre UPS system. I can set the output voltage and current limit functions which works fine for this application. There are dedicated chargers available from the usual sources ebay/amazon/AliExpress etc.

There should not be any exposed pins. V2L to DC Converter via CCS2 to Power cable.
DC Converter to GTI - Wired.
GTI to 15A Socket - Continually plugged in.

The only thing that would ever get disconnected is the CCS2 at the vehicle.

I would suggest that it's hard wired in that case, no need for the plug and socket.

 

[johnb80]

Also, it's a grid tie inverter. It won't output power until it has seen the grid stable for one minute. If it is ever unplugged, it should detect the lack of load immediately and stop the power.

Yep, agreed the problem being the word 'should', what if it doesnt? Why use a plug and socket when it's never going to be unplugged?

 

[Barrie]

Its a power supply I stripped out of a datacentre UPS system. I can set the output voltage and current limit functions which works fine for this application. There are dedicated chargers available from the usual sources ebay/amazon/AliExpress etc.

I would suggest that it's hard wired in that case, no need for the plug and socket.

Excuse my ignorance but just a regular battery charger ? You mention dedicated charger. Like an Eg4 chargeverter ? Do you have a link to one you say can replicate your situation ?

 

[johnb80]

Excuse my ignorance but just a regular battery charger ? You mention dedicated charger. Like an Eg4 chargeverter ? Do you have a link to one you say can replicate your situation ?

I think we may have crossed purposes here, I'm not talking about an EV wallbox / charger. I'm talking about a 3kW power supply with adjustable voltage and current limit. This is used to charge the house batteries directly and this charger is fed with power from the EV.

Sorry for any confusion.