Our recently purchased MG4 EV has a 51kwh battery, roughly equivalent to a 4250Ah 12v lithium battery ....... I wanted to use this stored electricity to run things in the motorhome when free camping if required.
The MG4 has a function called V2L (vehicle to load) where the electronics used to charge the car battery from an AC supply, can be reversed to supply AC @ 220vac at up to 7Kw, about the same amount as my 5kva Victron inverter supplementing a 15 amp caravan park supply can achieve.
I had the choice of:
Buying genuine for around $250 but that is restricted to around 2200w, they claim more, but in reality, that is all you can get.
Buy a unit from EV Chargers Australia for around $500 with a built in RCD and 2 x 10 amp power points ..... but still only 2200w
Buying UK genuine at around $750 and up to $975, output a full 7kw but came with all sorts of additional bits related to functioning to suit powering multiple UK devices with those strange UK plugs sockets
Buying an adaptor that would suit a 10 amp extension cord from evilbay for anywhere between $45 and a rather expensive $120 https://www.ebay.com.au/itm/37626173781 ... R_rIp5HiZQ that looks exactly like the one I bought for $25 from Aliexpress
When it arrived, naturally, it didn't work
A few hrs on Google looking at everyone's idea of what was safe, what worked and didn't work and what would happen if you didn't buy a genuine MG part, like you future birthdays would be cancelled or something .....
So, lashed out and spent $4 on a mix of resistors, pulled the non working item to bits to find out why it didn't work, and discovered this This is the resistor and diode required to make the socket a 6 amp battery charger
If you are going to copy stuff, at least start with the right thing ....So, armed with the knowledge Dr Google supplied, after running through the critical thinking filter, I came up with this to replace the incorrect bits
Heatshrink and liquid electrical tape to protect from any cross contact shorting inside the rather compact enclosure The photo looking in from the top doesn't actually make sense unless you saw it up close
The end result
Extension lead powering the Winnie Rooftop rattler set to heat, outside temp 16.5*C The amount of power being drawn from the MG4 shown on it's information screen. It also shows the limit it will allow the MG4 battery to be discharged before it shuts the V2L function off, and the guestimated range that will give me to find somewhere to recharge it. That can be adjusted from the 20% min up to 90% SOC if you wanted This is powering the whole motorhome, including the Victron inverter's battery charging ability, the microwave, electric hot water element and the 3 way fridge running on mains power, along with the 12v lights and water pump and electric blankets for later tonight.
This makes a very handy electrical jerry can that doubles as a run around vehicle with a range of 320kms driven the way I drive, or 420kms driven the way whoever sets the mixed use cycle range they advertise on the stickers
I'm happy with the way it has turned out. I will be buying an RVD from RVD safe to add into the supply side, to both add an additional protection path in case the 2 RCD's in the circuit don't trip .... although the Victron Multiplus is set up to create an earth/neutral link if it doesn't sense one in the supply side, and to protect against reverse polarity wiring at a caravan park ..... found a lot of those over the yrs, the handyman trying to be an electrician and stuffing it up
T1 Terry
