V2L - we have ignition

[kiwi]

Home made V2L cable in time for New Year’s BBQ:

The cable is made out of a Phoenix Contact CCS AC charging cable I scored on a local auction site.

The yellow outdoor weather proof cord socket is from a local hardware.

The cable’s existing 680 ohm ID resistor (sets AC charge rate to 20A) has to be swapped for a 2,000 ohm resistor (sets discharge rate to 2.3 kW max) to suit the MG. Cable works on both my wife’s 2023 ZS EV 51kWh Excite basic trim and my MG4 64kWh Essence (Trophy) visible in the (background.

The resistor goes between PP and PE. I did not loop CP to PP as suggested by others as I wanted to mimic the wiring of the official MG cable.

The supply voltage I measured was 217V. The earth pin is not bonded to the car earth so be careful! Because of this only double insulated appliances only should be used in my view.

Happy new year.

 

[Grriff]

Looks good! Could you not include an RCD (Residual Current Device) in the circuit to improve safety?

 

[kiwi]

Maybe… the RCD works by detecting the imbalance between the currents in the phase and neutral which is caused by current from the phase (usually) going via the victim to earth.

Without a proper earthing arrangement I’m not certain how well that will work but I will try it with a portable plug-in RCD and see what happens.

Here’s the V2L cable in action:

 

[Grriff]

A hope for the future. It's chilly (10°C) and wet here.
I have an extension socket with an RCD, two miniature circuit breakers protecting three sockets that I originally bought for camp site hookups. I've used it to power a battery charger and it worked well.

 

[kiwi]

The MCB (circuit breakers) are a good idea but I don't envy your weather.

While my V2L lead is basic, the yellow multi box is a rugged 'site safe' type that features a neon illuminated on/off switch and a 10A cut out. The illuminated switch (which I leave on) is a useful reminder that the vehicle inverter is running. NZ plugs are rated for 10A loads.

Originally I was going to terminate the cable directly into the multi box but I couldn't find a suitable gland and the makings for decent cable retention. The single weather proof cord outlet provided both and avoided needing to drill the multi box.

I also have an 16A rated caravan style inlet to the house switchboard for a sub circuit of MCB protected outlets in the kitchen and living areas already set up for a generator as we're in a rural area. The weather proof outlet on the V2L cable allows me to run a dedicated extension cord with the appropriate matching plugs without using having to use the multi box.

I think the single outlet on the V2L cable combined with the dedicated extension cord is a neater solution for that application as power failures and stormy weather seem to go together. When powering the house I won't need to use the multi box out in the rain.

 

[T1 Terry]

I bought one of those multiplug adapters and made a 15 mtr extension cord using 6mm sq conductors and 1.5mm sq earth with an industrial 20 amp plug and socket that screw together to make them weather tight ....... naturally, the 20 amp plug doesn't fit in the multiplug adapter, but a 15 amp does, next, the adapter doesn't tell the MG 4 it is a load plug, so I'm guessing it is the wrong resistor value ..... still a work in progress .....

T1 Terry

 

[kiwi]

It only works properly one way: a 2,000 ohm resistor (gives 217 VAC and 50 Hz, with max load of 2.3 kW to suit Oz/NZ plugs) between PP and PE at the car end of the cable. Break out your multimeter and check.

 

[T1 Terry]

Reading through a lot of forums and a lot of posts, the 2,000 ohm resistor restricts the output to 10 amps, but a 470 ohm resistor supplies up to 32 amps. I guess they changed to using only the 2,000 ohm resistor to avoid people plugging a standard 1mm² conductor cable with it and overloading the cables capabilities.

I went for the big 6mm² conductor cable to minimise voltage drop and carry the higher amps if needed. It works very well running my mig welder from a 10 amp power point where a 2.5mm² conductor cable resulted in poor welds due to voltage sag.

I have just purchased a CCS2 plug with 250 amp capable DC pins as well, I'll doubt I'll ever feed that much current in or out, but better to have the ability to handle more current than required, rather than stressing the pins and sockets by attempting to push more current through than they were designed to accept.

My first project with this DC plug will be building a 400 VDC open circuit solar array and direct solar charging rather than the losses converting from high voltage DC to lower voltage DC for battery charging, then back up to 230 VAC for EV charging .... probably result in the slowest DC rapid charger ever, but that doesn't really worry me too much

T1 Terry

 

[kiwi]

No one can say definitely if the inverter is safe at loads above 10A.

I care about the warranty and I don’t want MG to have an excuse to say that I blew the inverter with a home made lead. Hence I stuck to the MG lead wiring and resistor value.

How would MG know? I understand the car logs things like V2L usage along with heaps of other things in one of the modules.

So yes you can draw more current with a different resistor, but that doesn’t mean you should.

 

[T1 Terry]

The ones in Britian come with heavier cable, they have better power points over there. They run the 470 ohm resistor, I doubt they make a special MG 4 to send over here ..... but I have 2 spares if I do fry one so, I'll take the risk

T1 Terry

 

[kiwi]

Yes I’ve lived in the UK, so the outlets there are nominally 13A but derate to 10A for continuous use. Just like the Type I plugs used Oz/NZ and some other countries are derated to 8A.

I haven’t seen an official MG lead reported with 470 ohm resistor. I’ve seen 470 ohm mentioned lots of time when I researched building my own lead and I’d love to confirmation that MG uses this value.