Using car battery as a power source at night.

[Johncc]

Apologies if this has been discussed already I'm unable to find anything on a quick search.

I soiled my pants when I realised how much my heat and power cost are going up in August when my current deal ends (circa 400%). I'm now getting solar panels fitted and looking at heat pump installation costs.
Can the car battery fast charger be reversed i.e. Charge with solar during the day and reverse to power the house at night?I

Obviously not to be recommended before a long journey but I think 4-5 kw would be enough for a typical evening

 

[Alb]

Some models can do vehicle to home but none of them do vehicle to grid.
What car do you have?

 

[Johncc]

ZS long range so a 77kw battery.
Electric costs are about 75% and gas over 400% dearer than my current deal which runs out end August.
It means heat pumps may become a viable alternative as a damage limitation exercise.

 

[tsedge]

Apologies if this has been discussed already I'm unable to find anything on a quick search.

I soiled my pants when I realised how much my heat and power cost are going up in August when my current deal ends (circa 400%). I'm now getting solar panels fitted and looking at heat pump installation costs.
Can the car battery fast charger be reversed i.e. Charge with solar during the day and reverse to power the house at night?I

Obviously not to be recommended before a long journey but I think 4-5 kw would be enough for a typical evening

There are people who have done this and there are threads covering it on the forum.

There are a number of problems, you cannot connect the car to the grid, so when this has been done people have had an isolator switch fitted to isolate the house from the grid and then switch to the car. When this happens power is temporarily interrupted which is inconvenient.

The other issue is that cars like the MG4 have a rated limit of 2-3kW in V2L mode. I don't know what the ZS can do. People have found the MG4 will provide up to 7kW but it is unknown if this is sustainable or will cause long term damage.

It should go without saying that you should not attempt this without a qualified electrician.

Here is a relevant thread:

V2L Test. 7kW output...

Both myself and my neighbour have our MG4s wired to our household consumer units to run the house directly from V2L. We were told the MG4 output only 2.2kW, Our old Kia EV6 output 3.5kW. Today we decided to push them as far as we could.. With a meter on the input, we ran 2x 600W IR Heating...

www.mgevs.com

 

[smokie]

Also check out heat pumps fully to ensure it'd be suitable for your home, as I'm reading quite a few tales of people who have been mighty disappointed with retrofitted ones (i.e. onto an existing radiator system) during the colder weather. And whether you can get enough solar panels (and at the right price) to make a difference.

 

[Johncc]

Thanks for link tsedge, so it appears it can be done. The set up I'm having installed includes a backup battery so I wonder if the car battery can be used to top up the back up battery. Must admit I am in no way qualified to do this and am waiting for a response from the installation company as to what is feasible.

Smokie, you are right. I don't think it's worth swapping at the moment, despite the increases the cost of swapping to electric gives only minimal savings. My place is 7 years old so the boiler is only about half way through its life. Looks like the Wife will be getting thick jumpers for Christmas

 

[DeMille]

Thanks for link tsedge, so it appears it can be done. The set up I'm having installed includes a backup battery so I wonder if the car battery can be used to top up the back up battery. Must admit I am in no way qualified to do this and am waiting for a response from the installation company as to what is feasible.

Smokie, you are right. I don't think it's worth swapping at the moment, despite the increases the cost of swapping to electric gives only minimal savings. My place is 7 years old so the boiler is only about half way through its life. Looks like the Wife will be getting thick jumpers for Christmas

Most probably the battery transformer-charger is connected in series between grid and back up load and is not a hybrid suitable for parallel use with the grid ( able for synchronizing with GRID.) if you want to be able to top up your battery storage using V2L you have to use a TS ( transfert switch). This can be manual operation or an ATS. Using an ATS the V2l conection should have priority and GRiD connected as emergency pwr. This way if V2L is available the switch automatically will connect V2L to the load ( within 50ms). If V2L fails it will switch back to GRID. This way the home pwr is connected to V2L, not only back up pwr. if only back up pwr must function you have to install the ATS between bat transformer AC side and back up load but in the case batt will not be charged by V2L.
What is the total capacity of the battery and what is the charging and discharging limit? Is it a lead battery or LFP; if LFP, does it has a BMS? What value is the pwr limiting CB for back upload? Using an MG with 3 p 11KW internal charger one should use a 1p 32A V2L socket and 6mm2 wiring or and the socket must be fused to limit the max load corresponding the wiring used. max load is 1p 32A.

 

[Johncc]

All gone tits up as the solar company turned up with a 'on roof' rather than 'in roof' fixing system which we paid for.
We had a 'on roof' system in a pervious house and were plagued by pigeons so it's back to the drawing board. Netting worked for a while but the scallywags broke back in and kept us awake night and day.
A pity because I've seen the system on a similar property but I have lost all trust in the company we selected for the work.

 

[smokie]

My neighbour put metal mesh around our panel arrays a year or so back. The birds didn't take any notice for the first ten years which was odd. This kind of stuff.

Amazon product ASIN B07KXYG2BT

 

[Johncc]

Yep, similar to what we had - lasted a couple of years - thankfully we had moved.
Our old neighbours sent a recent picture and it looks like a bird sanctuary.
Once pigeons decide this is home they are very persistent.

 

[DeMille]

All gone tits up as the solar company turned up with a 'on roof' rather than 'in roof' fixing system which we paid for.
We had a 'on roof' system in a pervious house and were plagued by pigeons so it's back to the drawing board. Netting worked for a while but the scallywags broke back in and kept us awake night and day.
A pity because I've seen the system on a similar property but I have lost all trust in the company we selected for the work.

Something like this?

 

[Johncc]

Not quite.