Connecting a V2L car to a house as a battery.

[johnb80]

I think I'd like to gauge his reaction, anyway.

Absolutely, it will be interesting to see what he says. When I was shopping around for my solar installation the number of pro's that couldn't answer the technical questions I asked was unbelievable. I actually obtained 30 quotes for the install, only 1 answered my questions and really understood where I was heading. There wasnt anything out of the ordinary really, all of them quoted a 3.16 kW inverter, I was asking why and why we couldn't have more, break even calcs, optimisers etc. I think most of the people were sales rather than technical and they were rapidly out of their depth.

 

[Rolfe]

My guy is a one man band, and usually keen to learn something new.

 

[johnb80]

My guy is a one man band, and usually keen to learn something new.

Good luck - from some carrot crunching bloke in Lincolnshire

 

[creeppea]

My guy is a one man band, and usually keen to learn something new.

Hi Rolfe,
Did your electrician run a mile or did your manage to talk him into doing this?

 

[Rolfe]

Haven't talked to him yet!

 

[johnb80]

Today is the first time Ive used V2L in anger as it were. Usually I'm running out of house batteries by mid afternoon following the Christmas dinner kitchen power use etc in the morning. This year I set up our V2L, I had it charging my DIY batteries at 3 kW and Ive used 28 kWh out of the MG5, there's still plenty of house battery capacity left to take us to midnight. Absolutely no dramas with this setup, it worked really well supplying the whole house.

 

[NLMGSAN]

So your batteries are charged by panels and car battery using V2L? Are these batteries singles phased?

 

[johnb80]

So your batteries are charged by panels and car battery using V2L? Are these batteries singles phased?

I have two batteries, a 7kWh one as part of my Growatt Solar installation and my DIY 14 kWh system. Both inverters are grid tied and they work reasonably well together. My V2L system works by having a 3 kW battery charger connected onto the DIY battery. A reasonably continuous 3 kW was taken from the MG5 feeding a LifeP04 battery charger which was connected to the DIY 14 kWh battery, the same connection goes to the Victron Inverter which enabled the system run as if it had a 44 kWh battery connected. We ran heat pumps, 2 ovens and cooking rings as well as the immersion heater all day. Because I was putting power from V2L into my house system via the battery connections, the whole house was powered from the inverters and it was easy and convenient to do, no separate plugs on appliances etc, just carry as if it was grid powered.

 

[decrep]

It's a pain at the moment, that you have to buy another battery in order to use the car to power your house. I'm tempted by the idea, but think I'll wait for a while to see if V2G develops. The political will seems to be developing, and I think prices should drop if it becomes, "a thing"

 

[johnb80]

It's a pain at the moment, that you have to buy another battery in order to use the car to power your house. I'm tempted by the idea, but think I'll wait for a while to see if V2G develops. The political will seems to be developing, and I think prices should drop if it becomes, "a thing"

The difficulty is synchronising the AC power from the car to the grid supply, thats what the inverter does. You dont need an additional battery this was just my way of adding the vehicle supply into my house, it was a simple solution to a complex problem.

 

[decrep]

But I would still have to buy a battery to do it.
The solar and the car would charge that battery which would be connected to the inverter. At the moment I can't connect the car to the inverter,

 

[johnb80]

But I would still have to buy a battery to do it.
The solar and the car would charge that battery which would be connected to the inverter. At the moment I can't connect the car to the inverter,

You don’t have to buy a battery, you could just buy a 3 kW hybrid inverter, grid to it and supply it from the V2L and a suitable power supply.

 

[siteguru]

An inverter typically takes DC input and gives AC output? Or does yours also allow for an AC input?

(The output from the car via V2L is AC).

 

[charlie bravo]

My inverters have a single AC input I just use a ATS to be able to switch between Grid power input and a secondary AC source like V2L

Wow how many years is it going to take, to recoup the expense, then the up keep

 

[charlie bravo]

Wow how many years is it going to take, to recoup the expense, then the up keep

 

[decrep]

So I already have an inverter for my solar, I'm fairly sure it doesn't have an AC input. If I'm going to have to buy anything else, I'll wait until V2G becomes available.

Just checked and a 220v AC converter to 400V DC is $2,200

 

[johnb80]

An inverter typically takes DC input and gives AC output? Or does yours also allow for an AC input?

(The output from the car via V2L is AC).

You missed the last sentence, V2L and a suitable power supply.

Just checked and a 220v AC converter to 400V DC is $2,200

Why 400V DC?, if you have a hybrid inverter (one that use a battery supply) you would feed typically 50v at 3000W. Switch mode power supply for this would be circa £80-100

Wow how many years is it going to take, to recoup the expense, then the up keep

Upkeep is almost zero and cost not a lot so not many years.

 

[decrep]

I had a feeling my inverter has a 400vDC input, but I'll need to check that.

my inverter is 80v-500v input. looks like it doesn't have 2 inputs, but is "battery ready", I don't like the idea of connecting a power supply to the battery connection, it's not going to accept a charge, could cause all sorts of problems

 

[Barrie]

That input range is for solar. Minimum 80v to maximum 500v. All hybrid or off grid (all in one) inverters have an AC (grid) input.

 

[johnb80]

I had a feeling my inverter has a 400vDC input, but I'll need to check that.

Thats likely to be for solar panels. Most battery inputs are 50v or 100v.

my inverter is 80v-500v input. looks like it doesn't have 2 inputs, but is "battery ready", I don't like the idea of connecting a power supply to the battery connection, it's not going to accept a charge, could cause all sorts of problems

It wouldnt cause any issues at all. If the power supply is sat there giving out 50v what's the difference to a battery doing just that? If the inverter raises the voltage to charge the battery that wont cause issues either to the power supply.
I've just tried exactly this with my Victron inverter and the power supply I use as a battery charger. With my batteries unplugged and the MG5 supplying the PSU the Victron carried on supplying up to 2.9kW then the MG5 supply couldnt supply enough power. Switching the inverter over to charge mode, it's DC terminals voltage raised from 50v to 55v and it just sat there sensing the battery was charged. No drama, no smoke, no problems.