Connecting a V2L car to a house as a battery.

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.
It's me who should be saying sorry ! I may have confused you ! I am looking for a charger/device that I can plug my V2L from my Marvel R into that will allow me to charge my Lithium batteries that are connected to my solar system. I want to use the battery in my car to top up my house batteries.
 
It's me who should be saying sorry ! I may have confused you ! I am looking for a charger/device that I can plug my V2L from my Marvel R into that will allow me to charge my Lithium batteries that are connected to my solar system. I want to use the battery in my car to top up my house batteries.
We are talking about the same thing then :D

Something like this will do it depending on the voltage and capacity of your battery.
 
A 3kW charger would be a good fit, maxing out the MG V2L and would extend the capacity of your storage system considerably.
Thanks again for the advice. The same as the one in the link you sent me ? Which version ? My issue is that once the sun goes down my battery is not enough to see me through the night and rather than buy another one I want to utilise the V2L in my Marvel but I don't want to attempt to connect it to the grid like some people are trying to do. I charge the car during the day via solar.
 
Thanks again for the advice. The same as the one in the link you sent me ? Which version ? My issue is that once the sun goes down my battery is not enough to see me through the night and rather than buy another one I want to utilise the V2L in my Marvel but I don't want to attempt to connect it to the grid like some people are trying to do. I charge the car during the day via solar.
The beauty of doing it this way is that your whole house is supplied and there's no switching to do etc. The 3 kW version would be a very good fit for your system, it would work very much like a range extender on a car.
 
The beauty of doing it this way is that your whole house is supplied and there's no switching to do etc. The 3 kW version would be a very good fit for your system, it would work very much like a range extender on a car.
Many thanks. Which model do I choose as there are lots of different voltages ? Is that a 3kW version as it mentions 800W, 1500W and 3000W !!
 
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I'm interested that your charger was so cheap. Every time I click on a link to a suggested product I come to a page with an item costing several hundred pounds.

I haven't gone through a winter with my new solar/battery system yet, but the idea that I could top up the house battery from my car battery if the house usage exceeded the battery capacity on a particular day is quite attractive.
 
I'm interested that your charger was so cheap. Every time I click on a link to a suggested product I come to a page with an item costing several hundred pounds.

I haven't gone through a winter with my new solar/battery system yet, but the idea that I could top up the house battery from my car battery if the house usage exceeded the battery capacity on a particular day is quite attractive.
Here you go m'lady:-

LifeP04 50A Charger
 
It's coming up at £150 for me.
Correct, the prices have gone up quite a bit. I adapted a power supply for a UPS to do mine, it cost me circa £20 ;)

It terms of £150 it's not a bad price for linking your 50kWh plus battery into your house system.
 
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No, I think you're right. It's something I might do once I see what my winter consumption looks like.
It's relatively simple to do. V2L lead from your car, 3kW or smaller power supply plugged in feeding onto the wires between the inverter and the battery, big thick red and black cables. In operation it supplements the house battery with a few watts from the car battery, as the house battery runs down, more will be taken from the car until it's 50:50. Most power supplies have a trim on the output voltage where you can increase or decrease the output. I've set mine up when the house batteries are down at around 60% the power supply (and the car feed) is at 3000W, the maximum the car can do. It works just like a range extender on an EV like the BMW i3, the car batteries just sharing some of the load. It was useful at Christmas having had two ovens going all morning and heatpumps running etc.
 
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I was thinking about New Year (I'm usually with friends elsewhere at Christmas.) I thought I might talk to my installer about it.
Good idea although he may run a mile at the thought of this o_O and I do understand why. Why would he get involved in anything outside his comfort zone, what's in it for him? Many house batteries have two sets of sockets on the battery supply for paralleling them up, the power supply can be plugged into the vacant pair of sockets and operate in the same way.

All he needs to understand is that you are not charging the house battery merely supply additional energy from another source to the port on the inverter. LifeP04 cells have a very flat line in voltage 'v' SOC but there is a change that takes place, as the house battery drops in voltage the power supply will start to supply some of the load eventually up to it's maximum output of 3 kW or whatever rating you choose. The house battery is protected with it's BMS inline and would not allow any voltages outside spec to be input to the battery.

LifeP04 voltage chart.PNG


As you can see from the voltage chart above, a 48v LiFeP04 battery has a voltage of 52.2V at 50% charge. If you trim the power supply voltage to that level when your house battery starts to drop below that point the power supply will start to feed the DC into the inverter with the current from the house battery falling to zero.

It sounds more complicated than it is, essentially it's two wires a red and a black one connected onto the DC terminals of the inverter. The power supply plugged into the car job done.
 
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