MG4 solar charging

[Tertim]

I purchased my mg4 in August this year and was assured by the dealer that everything was checked and latest software was installed! However the HVAC temperature was under reading, no voice recognition and software not updated. The dealer has undertaken to rectify these issues, apart from these issues I'm delighted with my car and just love the peace and quiet whilst driving.
I have solar panels at my property and for 8 months of the year I have excess solar power which I intend to charge the car with the granny lead.
I would be interested to here from other members who charge with solar.

 

[Jomarkh]

I purchased my mg4 in August this year and was assured by the dealer that everything was checked and latest software was installed! However the HVAC temperature was under reading, no voice recognition and software not updated. The dealer has undertaken to rectify these issues, apart from these issues I'm delighted with my car and just love the peace and quiet whilst driving.
I have solar panels at my property and for 8 months of the year I have excess solar power which I intend to charge the car with the granny lead.
I would be interested to here from other members who charge with solar.

I would use solar to charge my car via a Zappi but I get paid 15p/kWh export and charge overnight at 7p/kWh.
Can you change the current on your granny EVSE otherwise it will use 10A about 2.2kW

 

[Bam Bam]

I would be interested to here from other members who charge with solar.

Yeah, for the last 18 months or so in the UK it has been better to charge on cheap overnight tariff and export the solar during the day.

That will probably end in a few years and we will go back to self-consumption.

If you don't have the generous export tariff then I guess you will be trying to plug in during the times when you've got surplus solar.

Does your granny charger have any kind of smart control or timer setting (I wasn't aware that they did). If not, I guess you could set the car so it only charges during daylight hours but you'd have to remember to turn that off if you ever wanted to charge outside those times.

 

[Tertim]

I would use solar to charge my car via a Zappi but I get paid 15p/kWh export and charge overnight at 7p/kWh.
Can you change the current on your granny EVSE otherwise it will use 10A about 2.2kW

I installed the solar system myself, it's not tied to the grid and I have a hybrid controller with a 16kw battery, I only take power from the grid in the winter. The plan is to plug in the granny charger during the day on a timer to disconnect when the sun goes down.
I normally charge from a 7kw charger installed in my barn which is on a night tariff.

 

[Tertim]

Yeah, for the last 18 months or so in the UK it has been better to charge on cheap overnight tariff and export the solar during the day.

That will probably end in a few years and we will go back to self-consumption.

If you don't have the generous export tariff then I guess you will be trying to plug in during the times when you've got surplus solar.

Does your granny charger have any kind of smart control or timer setting (I wasn't aware that they did). If not, I guess you could set the car so it only charges during daylight hours but you'd have to remember to turn that off if you ever wanted to charge outside those times.

Yes that's my plan hopefully I'll have free power for at least 8 months of the year

 

[decrep]

We have a big advantage here in aus, plenty of sunshine.
We can charge our car purely on sunshine, even in the Winter.
I'll shortly be able to automatically only charge when there's excess solar, once the EVSE people get the software working.
We have 9.6kW panels and a 5kW inverter, so I can charge at 4.5kW and still have a bit left over for running the house.

 

[Kenno]

We have a big advantage here in aus, plenty of sunshine.
We can charge our car purely on sunshine, even in the Winter.
I'll shortly be able to automatically only charge when there's excess solar, once the EVSE people get the software working.
We have 9.6kW panels and a 5kW inverter, so I can charge at 4.5kW and still have a bit left over for running the house.

And we get b* all for exporting power, so we want to use it or store it, and only if we can't do that we export it. Currently in Sydney I get 8c per kWh exported (around 4p). Where as conversely in the UK, you can probably make more money exporting and then charging on a cheap rate

 

[Pete G]

I have an MG ZS EV, and live totally off grid. We charge our car from our solar system with a zappi EVSE.
The Zappi has settings to allow you to just use excess solar or to use some grid and some solar power.
I have a battery inverter that pretends to be the grid and two second hand grid inverters that are connected to banks of solar panels. So when charging the car most of the charge comes via the grid interactive inverters and some comes from the battery inverter.
The Grid inverters are connected to around 6kw of panels and the Battery inverter is connected to 5 kilowatts of panels.
It is a slightly complicated system called AC coupling if you want to look up how it works.
When there is full sun our car can charge at up to 5.5 kilowatts. Theoretically the Zappi can charge at 7kw but we would need more panels for that.
When the batteries are fully charge the Grid interactive inverters are disconnected by relays, so the batteries are not overcharged.
Pete

ps, in your situation using a granny 10 amp charger will only give you about 10 kilometres of range per hour of charging. So it will depend on how far you drive whether this is enough for your needs.

 

[Tertim]

I have an MG ZS EV, and live totally off grid. We charge our car from our solar system with a zappi EVSE.
The Zappi has settings to allow you to just use excess solar or to use some grid and some solar power.
I have a battery inverter that pretends to be the grid and two second hand grid inverters that are connected to banks of solar panels. So when charging the car most of the charge comes via the grid interactive inverters and some comes from the battery inverter.
The Grid inverters are connected to around 6kw of panels and the Battery inverter is connected to 5 kilowatts of panels.
It is a slightly complicated system called AC coupling if you want to look up how it works.
When there is full sun our car can charge at up to 5.5 kilowatts. Theoretically the Zappi can charge at 7kw but we would need more panels for that.
When the batteries are fully charge the Grid interactive inverters are disconnected by relays, so the batteries are not overcharged.
Pete

ps, in your situation using a granny 10 amp charger will only give you about 10 kilometres of range per hour of charging. So it will depend on how far you drive whether this is enough for your needs.

I'm retired so don't have a daily commute, probably drive about 6000kl/year mostly local.
I'm hoping to charge most afternoons which should be sufficient for my needs, I'll post my results next summer.

 

[Everest]

I would be interested to here from other members who charge with solar.

we do. Has been completely free for 9 months of the year and odd top-ups for the rest of the year.

I installed the solar system myself, it's not tied to the grid and I have a hybrid controller with a 16kw battery, I only take power from the grid in the winter. The plan is to plug in the granny charger during the day on a timer to disconnect when the sun goes down.

Great. How many panels do you have and what power will your inverters generate? We put our surplus into the EV's in the summer, usually charging at around 16A from solar, sometimes at 24A, occasionally at 10A.

Should work well for you as you have batteries to keep things going when the clouds pass over.

 

[Tertim]

we do. Has been completely free for 9 months of the year and odd top-ups for the rest of the year.


Great. How many panels do you have and what power will your inverters generate? We put our surplus into the EV's in the summer, usually charging at around 16A from solar, sometimes at 24A, occasionally at 10A.

Should work well for you as you have batteries to keep things going when the clouds pass over.

I have 4.5kW of solar panels, 16kWh battery and 6.2kW inverter, I live in a traditional cottage in the west of Ireland, even though solar is not great here it's still sufficient to run my cottage

 

[Cabansail]

I am going to re-jig my home solar set up and then self charge from Solar.

Right now I use the DC Charger in town, which is Solar Powered. It would be slightly cheaper to Home Charge but that would deplete the home battery. There are storms about, and that leads to Blackouts in my area. If the battery is low then I am vulnerable.

 

[Pete G]

I am going to re-jig my home solar set up and then self charge from Solar.

Right now I use the DC Charger in town, which is Solar Powered. It would be slightly cheaper to Home Charge but that would deplete the home battery. There are storms about, and that leads to Blackouts in my area. If the battery is low then I am vulnerable.

If you use an EVSE like a Zappi then it has, the ability to use only excess solar power,( eco++) or some battery and mostly solar power in Eco mode.
There is a fast charge setting too, and you can set the amount of power it will draw from the batteries to whatever percentage you want.
I am sure there are other smart EVSEs that can do that too.
pete

 

[Cabansail]

There are many options, depending on budget. One thing I am looking at is to move over to three phase. That would allow better charging options. It could be done with the main house using just the single phase, with solar and batteries. Then the other phases would be just for the car, and maybe A/C.
Have been advised I may be better off buying/selling excess power on the open market.

 

[Corindikev]

I recently installed 20 x 440 watt bi-facial solar panels, a Fox ESS 10kW hybrid inverter and an 18.64 kWh battery. I have a ZJbeny 32 amp single phase charger.

I charge my MG4 and my 80 volt zero turn ride on mower exclusively from solar. Even though I get free energy from the grid every day from 11:00am to 2:00pm I have not used any as the system uses the solar energy I have produced first, then battery storage, so for the last month I have used zero GRID energy.

The new Bi-facial panels means some of the sunlight travels through and is captured after reflection from the roof below. The best I have achieved so far is 9.98kW from the 8.8kW of panels. They are mounted in a 7 East facing, 6 North facing & 7 West facing configuration on my 15 degree sheds roofs.

I reckon about a 5 year payback for the $11,600.00 cost.

 

[Everest]

How many panels do you have and what power will your inverters generate?

I have 4.5kW of solar panels, 16kWh battery and 6.2kW inverter,

IMHO that configuration sounds somewhat under-panelled. Understandable if you have limited space for panels though. I suspect that, unless your household loads are very low, there won't be a whole lot spare for EV charging.

If you have the space it would be good to increase the number of panels to something like @Corindikev's size...

I recently installed 20 x 440 watt bi-facial solar panels, a Fox ESS 10kW hybrid inverter and an 18.64 kWh battery.

 

[STG]

I'm retired so don't have a daily commute, probably drive about 6000kl/year mostly local.
I'm hoping to charge most afternoons which should be sufficient for my needs, I'll post my results next summer.

It will never work! That's what I thought but every time the sun comes out I have to go out with the wife so the car is hardly on the Zappi, so it mostly does it's charging between 2am and 5am at £0.15/kw

 

[decrep]

It will never work! That's what I thought but every time the sun comes out I have to go out with the wife so the car is hardly on the Zappi, so it mostly does it's charging between 2am and 5am at £0.15/kw

But he has a 16kWh battery, even if he's out when the sun shines, the battery will still top up. But I agree with Everest, to work well it needs more panels.

 

[Tertim]

But he has a 16kWh battery, even if he's out when the sun shines, the battery will still top up. But I agree with Everest, to work well it needs more panels.

I think I need to share more information with you. I installed my system 4 years ago and my daily average use is 6 to 7kw ,this includes heating water when battery goes into float mode. I built the water heating controller from some cheap modules I bought on AliExpress.
For 8 months of the year I generate on average 16kw / day which gives an excess of 9kw

 

[Everest]

It will never work

Well, it certainly can and it does, for us. All depends on your usage patterns and having enough PV and battery.

I think I need to share more information with you. I installed my system 4 years ago and my daily average use is 6 to 7kw ,this includes heating water when battery goes into float mode. I built the water heating controller from some cheap modules I bought on AliExpress.
For 8 months of the year I generate on average 16kw / day which gives an excess of 9kw

I'll assume you mean kWh, not kW. If so, then yes, I agree that is looks do-able. I must say 6kWh is a very atypical low consumption and I wasn't factoring that in with earlier comment. You're using an average of only 250W, including water heating!

Obviously you've done your calculations on usage and your figure of 16kWh concurs with the PVGIS figures for your location (JRC Photovoltaic Geographical Information System (PVGIS) - European Commission)

My 2p worth would be that having such a low household usage it will be most efficient to max out what power your inverter can deliver from solar + battery on the sunny days - i.e. being able to charge at the greatest possible rate will minimises losses within the EV due to its fixed quiescent draw when charging. So, if for example, your inverter can deliver 6.2kW and household usage is normally around 250W, then you should be able to dump up to 24A (around 5.7kW) into the EV once your batteries are getting full and your water heated up - even if that is only for 2 to 3 hours each early afternoon