MG5 Pre-facelift V2L (Diy)

[staarek]

As we know there's no V2L capability on Pre-lift MG5, so I decided to do a DIY version. The onboard charger is capable of delivering around 170amps to 12V battery, however the charging circuit fuse is 150amps, so we are looking at maximum 2.1kw max. I bought 2kw pure sine wave inverter, as I don't think i will be ever drawing more than 1.5kw. So far I tested it on 900w heater and it seems all good, the charger adjusts the current accordingly to the demand (i checked with amp meter). The maximum current i saw on the dashboard was 3 amp (3 x 400v = 1200w)

Link to a short video below:

 

[Gomev]

Have you taken that directly from the 12v battery connections ?

 

[staarek]

Have you taken that directly from the 12v battery connections ?

Yes, that's right.

 

[MickeySw]

As we know there's no V2L capability on Pre-lift MG5, so I decided to do a DIY version. The onboard charger is capable of delivering around 170amps to 12V battery, however the charging circuit fuse is 150amps, so we are looking at maximum 2.1kw max. I bought 2kw pure sine wave inverter, as I don't think i will be ever drawing more than 1.5kw. So far I tested it on 900w heater and it seems all good, the charger adjusts the current accordingly to the demand (i checked with amp meter). The maximum current i saw on the dashboard was 3 amp (3 x 400v = 1200w)

Link to a short video below:

No doubt this will work, not sure though, if the CCU is designed to continuously deliver 1.5kW as the 12V aux is usually kept topped up?

 

[Gomev]

No doubt this will work, not sure though, if the CCU is designed to continuously deliver 1.5kW as the 12V aux is usually kept topped up?

But it's bypassing the CCU by taking the feed direct from the 12v battery. This is the same as the setup in my shed. One PV panel on the roof, a leisure battery and an inverter connected to the battery which powers my tools etc.
Hopefully the car is in ready mode so that it's keeping the 12v topped up as the car 12v battery is not designed for this type of usage.

 

[staarek]

No doubt this will work, not sure though, if the CCU is designed to continuously deliver 1.5kW as the 12V aux is usually kept topped up?

True, so far i just tried 900w heater for about 15 minutes but hard to tell how is it going to be ina long run...

But it's bypassing the CCU by taking the feed direct from the 12v battery. This is the same as the setup in my shed. One PV panel on the roof, a leisure battery and an inverter connected to the battery which powers my tools etc.
Hopefully the car is in ready mode so that it's keeping the 12v topped up as the car 12v battery is not designed for this type of usage.

That's right, the car is "on" (started with a foot on a break) and the 12V battery is being constantly topped up. I check with a clamp meter and the charging current is being adjusted accordingly to the load. I've been "off-grid" for many years - also have a solar panel on the roof of my shed, small battery and an inverter (800w). setup mostly for lights and charging power tools batteries.

 

[BrianMcL]

Hi All,
New to the forum and looking for some advice on this one please.

I've got a MK1 LR Excite which I'm very happy with except for the lack of proper V2L capability.

I'm planning a few camping trips in the summer and the workaround here looks like a great compromise.

I understand the car can supply the battery with around 2kW which would be plenty (couple of lights, 500W plug in ceramic heater, electric blanket - don't judge me until you try it) but I'm slightly worried about drawing current through the existing 12V battery for an extended period might damage it.

Would there be any downside to using a couple of cheap 130Ah 12V leisure (in theory 3kWh in reality maybe half that) batteries connected to the car instead of the normal battery or would discharge damage to the battery not being a problem? - is the existing vehicle battery just acting as a "bridge" to complete the circuit between the HV battery and the pure sine wave inverter / load and won't suffer any degradation because it's not actually being discharged?

Thanks.

 

[kevin ellard]

Hi All,
New to the forum and looking for some advice on this one please.

I've got a MK1 LR Excite which I'm very happy with except for the lack of proper V2L capability.

I'm planning a few camping trips in the summer and the workaround here looks like a great compromise.

I understand the car can supply the battery with around 2kW which would be plenty (couple of lights, 500w plug in ceramic heater, electric blanket - don't judge me until you try it) but I'm slightly worried about drawing current through the existing 12v battery for an extended period might damage it.

Would there be any downside to using a couple of cheap 130ah 12v leisure (in theory 3kWh in reality maybe half that) batteries connected to the car instead of the normal battery or would discharge damage to the battery not being a problem? - is the existing vehicle battery just acting as a "bridge" to complete the circuit between the HV battery and the pure sine wave inverter / load and won't suffer any degradation because it's not actually being discharged?

Thanks.

I don't think you'd be going through the battery. The battery and your load would be in parallel. I'm not sure how well the preFL copes with being left on for an extended period - which could be a problem.

 

[BrianMcL]

Hi Kevin,
Good points - I was just thinking about using a couple of cheap batteries instead of the main "starter" battery to avoid putting any strain on it and make sure I still had plenty of power when I turned the car off.

Which I think is probably the wrong way to look at it - I don't need a starter battery in tip top condition which can supply all those amps to turn over a diesel engine when it's time to leave so I don't need to worry about that.

Thanks again,
Brian