Anyone using MG4 battery to power house ?

[BrianthatiscalledBrian]

We were told that you could discharge the MG4 battery to power your home, has anyone successfully tried this ?
We have a Wallbox Pulsar MAX charger and Octopus GO tariff so using 9.5p/kwh power to power the house is quite attractive.

 

[jpk]

It's vehicle to load not vehicle to home/ground. There's a video of someone who has managed it though

 

[Bricktop X PWR]

I do quite regularly, now we are heading into winter.

I live off grid, with 4000W of Solar Panels and a 500AH Battery Bank, with a 5000W hybrid inverter set up. (All my own work) and have used a 5000W LPG generator as my back up for the last couple of years.
Because you are connected to the National Grid, you will come under a great deal of strict regulations and will "have" to get a qualified electrician to set it up.

When I switch over to the car, I power the house (read cottage) and can charge the battery bank as well if required.

My total requirement is only 3500W when everything is switched on in my home so well within my existing set up.

Your average house will be a lot more than this if for example, you've got kids, Electric ovens, washing machines, tumble dryers all going off at the same time.

I do have all those things and need to manage how I use my appliances.

What's great about V2L is that I can choose in 10% increments, how much to discharge, so I am not caught out with less mileage than I require.
It will stop automatically at 20% remaining in the car, should I forget.

10% from the car can last between 8 and 12 hours, depending on what I'm doing, longer if it's just the fridge/freezer ticking over.

I haven't worked out the exact costs with regards to the LPG versus the cost of electric (charging) but I know that even at 36ppkwh ((Tesla)) I am spending much less than if I use the LPG generator or in an Emergency I have a Honda 2.2i petrol genny.

Whatever the costs, I can typically cut them in half, because the Solar Panels are more than sufficient for all my needs during the warmer sunnier months.

 

[siteguru]

The important words there were "I live off grid".

For anyone in the UK and connected to the grid then using your car to power the house is a very tricky issue to resolve ... earthing and safety of personnel at the DNO being a primary concern. (@Ayoull can explain about this much better than I can).

 

[Rolfe]

I know @QLeo lives off grid in Scotland. I'm waiting for him to announce a similar project!

 

[QLeo]

I know @QLeo lives off grid in Scotland. I'm waiting for him to announce a similar project!

Our setup is much more basic that @Bricktop1967 and like them, we have no need for other sources of power in summer. But at this time of the year, when sun is scare, shortlived and lacks power where we are just 8 degrees south of the Arctic circle, we need to replenish the battery one way or another every now and again. I would love to use the car for this, but just haven't got around to buying a cable.

We would not use the car to power the house. It would only power a charger to charge the house battery, so complexity is reduced.

 

[Bricktop X PWR]

Our setup is much more basic that @Bricktop1967 and like them, we have no need for other sources of power in summer. But at this time of the year, when sun is scare, shortlived and lacks power where we are just 8 degrees south of the Arctic circle, we need to replenish the battery one way or another every now and again. I would love to use the car for this, but just haven't got around to buying a cable.

We would not use the car to power the house. It would only power a charger to charge the house battery, so complexity is reduced.

My inverter has an "AC IN" which plugs directly into the car (or genny)
Really very simple. ?

Interestingly, the car is only supplying 210 to 220 volts by the time it hits the inverter.
The only side effect with all the 240volt equipment is the air fryer takes a little longer, but you wouldn't notice it with anything else. Sky box, TV, lights, etc.

 

[Mick b]

We were told that you could discharge the MG4 battery to power your home, has anyone successfully tried this ?
We have a Wallbox Pulsar MAX charger and Octopus GO tariff so using 9.5p/kwh power to power the house is quite attractive.

Yes l run a 2kwh heater, from heavy duty extension lead

 

[Tangoed Man]

My inverter has an "AC IN" which plugs directly into the car (or genny)
Really very simple. ?

Interestingly, the car is only supplying 210 to 220 volts by the time it hits the inverter.
The only side effect with all the 240volt equipment is the air fryer takes a little longer, but you wouldn't notice it with anything else. Sky box, TV, lights, etc.

Ah, so your inverter connects to your CU, and, presumably has all the fancy safety switch gear installed by a specialist electrician - hence your initial comment about 'Simple'! Was that costly, as I am thinking of doing that, but most electricians won't touch it?

 

[Bricktop X PWR]

Ah, so your inverter connects to your CU, and, presumably has all the fancy safety switch gear installed by a specialist electrician - hence your initial comment about 'Simple'! Was that costly, as I am thinking of doing that, but most electricians won't touch it?

Not sure your allowed to do anything if you are connected to the National grid?

The rules are different for me as I have no way to electrocute anyone except myself. ?

My inverter, which is a hybrid unit, and very clever (so I don't need to be) was £800.
You can pay a lot more or a lot less depending on your personal "Off Grid" Situation.

 

[Mick b]

Ah, so your inverter connects to your CU, and, presumably has all the fancy safety switch gear installed by a specialist electrician - hence your initial comment about 'Simple'! Was that costly, as I am thinking of doing that, but most electricians won't touch it?

You are not connecting to your consumer unit at all, you do need a plug that fits in the charging port that converts into a three pin plug that you then plug anything in up to 2.4kwh

 

[wattmatters]

You won't run your home from it, at least not easily, as the car has V2L capability not two-way power flow capability. I mean you could but you'd need to constantly swap plugs over to charge and to discharge. It's not a seamless operation.

V2L does however make for a useful home backup option.

All it requires is a power inlet (like a caravan might have) wired to your home's main circuit board via a break-before-make transfer switch. That way the circuits powered by the car's supply are isolated from the grid. Done correctly you can choose which circuits to backup, that way you can avoid accidental use of high power devices beyond the capacity of the car's inverter or your wiring.

It's no different to how you would wire up a home backup generator. A licensed sparky should be able to do that without much trouble.

I do that now with an off-grid PV and battery system.

I plan to use the MG4 as extra backup capacity. While I can plug it in to directly power the home, because I already have such a system I would instead use the V2L to provide supplemental charge for my home battery. I have a spare AC charger I can use for that. For us it would be handy in an extended outage (more than a handful of days).

 

[Corindikev]

Powering your house is not difficult but will require some modifications to your power distribution board. You will also need a V2L adaptor that is capable of 32 amps. The MG supplied expensive V2L cable is limited to 10 amps.

See the test done on this site. V2L Test. 7Kw output....

You will need a 3 way 100 amp main switch for Grid/Off/EV and a 32 amp RCCB (residual current circuit breaker) plus 6mm TPS twin core + earth cable to the main switch from an EV socket on the garage wall and preferably 6mm TC+E flexible cable from there to the V2L adaptor. Voltage drop will also be apparent and this will depend on total cable length. I am assuming single phase grid supply here.

This should all be installed by a licenced electrician.

The 32amp RCCB will trip if there is a continuous current demand greater that 32 amps. The cars output will shut off automatically as well when demand gets to this level.

Based on my normal daily usage from the grid my MG4 battery will power my entire house for 9 days if it was 100% full. The problem lies in demand so I could not run several high demand appliances at once like the electric jug, toaster and induction cooktop at the same time and as I have a vertical freezer and fridge freezer there may not be enough to charge the capacitor required to start the motors if other appliances are running.

All this takes is an understanding of the process and your own management of it.

Things will take longer due to voltage drop but they will still run OK. Nominal voltage is 230v but the grid in NSW normally delivers between 240 & 250 volts. The IEC standard of 230 volts at 50 hertz allows for +10% to -6% of the nominal voltage or 253 volts down to 216 volts. Tests from others have shown the MG4 V2L to be at the lower end at 216 volts.

 

[Rolfe]

We would not use the car to power the house. It would only power a charger to charge the house battery, so complexity is reduced.

That is a remarkably interesting thought.

 

[wattmatters]

Based on my normal daily usage from the grid my MG4 battery will power my entire house for 9 days if it was 100% full.

The MG4 has a minimum discharge limit at 20% SOC.

I did some sums and think allowing for the minimum SOC and a round trip to nearest fast charger (assuming a long outage was confined to our local area) which itself requires some of the battery while getting all the way back to 100% SOC is unlikely (90-95% more likely), we can expect perhaps 35-40 kWh of backup reserve capacity (Essence 64).

That would cover us for a few days with appropriate frugality (two homes), and help see out any inclement weather to allow the PV to be able to generate enough to get batteries charged back up.

It does have me considering selling my generator (a Yamaha EF3000iSE) as that's my current backup reserve.

 

[wattmatters]

That is a remarkably interesting thought.

It's how I intend to use it, if needed.

It means the load on the MG4's inverter can be controlled and maintained at a nice steady rate well within its capacity. With my spare charger I can adjust charging of the home battery in roughly 500 W increments.

 

[Rolfe]

I am looking at a home battery setup with solar panels. My neighbour in an identical house has a system he's very happy with and I'm thinking about just getting the same. He's an engineer and has done all the work so I might as well take advantage of that.

I'm told that many years ago this village was very prone to power cuts, sometimes lasting for days. They put in a new grid supply before I moved here and there have only been a few short incidents since. But you never know. My friends in Sussex were out for two weeks after the big storm in 1987.

If you have a lot of power in the car it makes sense to be able to feed it to the house in an emergency. I must ask my neighbour if he has made any provision for this.

 

[wattmatters]

See the test done on this site. V2L Test. 7Kw output....

Any ideas on where to get a V2L cable with the appropriate resistor and cable gauge and socket to enable higher discharge capacity?

 

[Bricktop X PWR]

Powering your house is not difficult but will require some modifications to your power distribution board. You will also need a V2L adaptor that is capable of 32 amps. The MG supplied expensive V2L cable is limited to 10 amps.

See the test done on this site. V2L Test. 7Kw output....

You will need a 3 way 100 amp main switch for Grid/Off/EV and a 32 amp RCCB (residual current circuit breaker) plus 6mm TPS twin core + earth cable to the main switch from an EV socket on the garage wall and preferably 6mm TC+E flexible cable from there to the V2L adaptor. Voltage drop will also be apparent and this will depend on total cable length. I am assuming single phase grid supply here.

This should all be installed by a licenced electrician.

The 32amp RCCB will trip if there is a continuous current demand greater that 32 amps. The cars output will shut off automatically as well when demand gets to this level.

Based on my normal daily usage from the grid my MG4 battery will power my entire house for 9 days if it was 100% full. The problem lies in demand so I could not run several high demand appliances at once like the electric jug, toaster and induction cooktop at the same time and as I have a vertical freezer and fridge freezer there may not be enough to charge the capacitor required to start the motors if other appliances are running.

All this takes is an understanding of the process and your own management of it.

Things will take longer due to voltage drop but they will still run OK. Nominal voltage is 230v but the grid in NSW normally delivers between 240 & 250 volts. The IEC standard of 230 volts at 50 hertz allows for +10% to -6% of the nominal voltage or 253 volts down to 216 volts. Tests from others have shown the MG4 V2L to be at the lower end at 216 volts.

Nice explanation ?

 

[Bricktop X PWR]

That is a remarkably interesting thought.

I suppose that is basically what I am doing here.
The car battery, charges my existing battery bank.
The bonus with a hybrid inverter is that it decides where to take the power from, to maintain my power requirements, over and above the limits of the car.

When initially plugged in, the inverter will bypass the battery and solar, and send power to my home.
The solar then concentrates on charging the battery bank.
If my demand goes up, the batterys come into play.
Although I have 5000W max to call on, I rarely go above 3500W

Depending on the amount of light and load, the inverter will then concentrate on adding charge to the battery from the car, whilst maintaining the appliances in my home.

Iconica 5000W 48V hybrid pure sine wave inverter with 80A MPPT solar controller and 100A mains battery charger, with parallel capability and Bluetooth (No Battery Required) https://amzn.eu/d/bJjK8mN