MG4 in Australia

[Corindikev]

Why import over 11kW unless this is during the free period.? Would it not be better to reduce the charging level of the car or battery or both so you are not importing energy & having to pay or it. If it is a good sunny day the charging would take a lot longer but if you are not planning on going anywhere that seems sensible to me before 11:00 or after 14:00..

Today my MG4 was down to about 40% & charged from 11:00 till 14:00 at about 7.1kW AC using some home battery as today is partly cloudy but drawing none from the grid & the battery will be back at 100% within a few hours. I don't have control of the software to be able to draw from the grid when it is free. Unless the temperature is mid to high 30s we leave the house open during the day. Even on those hot sticky humid days with the AC on I have still not imported any power since the system went in on 24 November.

 

[T1 Terry]

System really sucking down the juice (@ 24.6 kW), using all available solar + free grid energy to charge home battery, the MG4 via DC charger and power the home (ducted aircon going):

View attachment 42726

The load side is 12.5kW DC charger is voltage boosted to 400vdc, so 31.25 amps
The house is consuming 3.8kW AC, converted to AC and held @ 230vac 16 amps

The input side is 13.3kW DC but as yet, voltage unknown.
The grid supply is 11.28kW AC @ 230vac @ 49 amps, supplying the house direct, the remaining 7.5kw is converted to DC at ? voltage to charge the house batteries?

T1 Terry

 

[wattmatters]

Why import over 11kW unless this is during the free period.?

As mentioned...

using all available solar + free grid energy

Even though it was free, this is not a normal set up for our charging, I was just testing stuff.

It's pretty impressive being able to load up both the DC and AC sides of the system to simultaneously consume close to 25 kW.

The load side is 12.5kW DC charger is voltage boosted to 400vdc, so 31.25 amps
The house is consuming 3.8kW AC, converted to AC and held @ 230vac 16 amps

The input side is 13.3kW DC but as yet, voltage unknown.
The grid supply is 11.28kW AC @ 230vac @ 49 amps, supplying the house direct, the remaining 7.5kw is converted to DC at ? voltage to charge the house batteries?

It's not that easy to determine where exactly the DC solar power goes to. In reality you are pouring energy from a couple of sources into a big bucket and taking it out from the same bucket to power various loads.

Solar PV can directly charge either the car or battery via the DC bus but since combined battery + EV charging exceeded the solar PV output then the deficit was coming from the grid, plus of course powering the house.

If I go by the system's own accounting, it suggests the car took priority for solar PV, with the home battery using the supplemental grid energy. But it could just as easily have claimed the home battery was all solar PV and the car used some supplemental grid energy.

This is the supply and demand during that period. I didn't do it for long:

 

[wattmatters]

I didn't do it for long

For unusual reasons (taking guests for sightseeing run in the MG4), I had a proper need to do it again today but for much longer, this time 1 hour 20 minutes. Works great.

Afternoon storms killed PV output.

 

[T1 Terry]

For unusual reasons (taking guests for sightseeing run in the MG4), I had a proper need to do it again today but for much longer, this time 1 hour 20 minutes. Works great.

View attachment 42748

Afternoon storms killed PV output.

I've worked out the yellow part is solar, no idea what the other colours are ....

T1 Terry

 

[tsedge]

I've worked out the yellow part is solar, no idea what the other colours are ....

T1 Terry

There is a key at the bottom of the graph.

 

[tsedge]

For unusual reasons (taking guests for sightseeing run in the MG4), I had a proper need to do it again today but for much longer, this time 1 hour 20 minutes. Works great.

View attachment 42748

Afternoon storms killed PV output.

Do you have scope to add more solar PV?

 

[wattmatters]

I've worked out the yellow part is solar, no idea what the other colours are ....

See the legend below the chart.

Above the line is supply - solar, battery discharge and grid import.
Below the line is demand - household consumption, EV chargers, battery charging and grid export.

Do you have scope to add more solar PV?

Most of the best roof real estate is taken up with a pool solar thermal heating system. We've filled the rest with what PV we could fit.

If the pool system carks it, I may add more, or at least move some from less favourable spots to the nice north facing roof space. It's not that critical when you get three hours of free grid energy every day.

 

[T1 Terry]

See the legend below the chart.

Above the line is supply - solar, battery discharge and grid import.
Below the line is demand - household consumption, EV chargers, battery charging and grid export.


Most of the best roof real estate is taken up with a pool solar thermal heating system. We've filled the rest with what PV we could fit.

If the pool system carks it, I may add more, or at least move some from less favourable spots to the nice north facing roof space. It's not that critical when you get three hours of free grid energy every day.

Opened it in a new tab and then I could see them I'm starting to wonder if the marbles are rolling at all just lately

T1 Terry

 

[wattmatters]

Not sure in which thread it was but there was a question a while back about the charging plugs I have.

Here are the two types of plug I have:

On the right is the CCS Type 2 DC charging plug.

The black one on the left is a regular Mennekes Type 2 plug from our ZJBeny single phase 7 kW EVSE (which is partially in view at the bottom of the photo). The 3 ports across the middle are for the neutral, earth and L1 (live). Note that the two lower ports have nothing in them - those are for 3-phase cables with L2 and L3.

Our Sigenergy single phase AC EVSE has the same plug type. These are for supplying the car with AC power, which the car's on-board charger uses.

This is the Sigenergy AC EVSE:

Side view of the CC2 Type 2 plug from my Sigenergy DC charging module:

This is the same plug type as found on DC fast charge stations and connects directly to the battery, bypassing the car's on-board charger. The power flows through the two larger ports and the DC charging system reports on the car's SOC via the MySigen app (it communicates with the car's BMS).

And this is the Sigenergy stack with the DC charging module incorporated.

The stack is against the rear wall of our garage. The DC charge module is the second module down sandwiched between the energy controller (inverter) on top and the battery modules below. The charge cable emerges from the bottom left of the stack. It's quite a thick/heavy cable and is 10m long.

The cable hanger on the side wall allows for stowing the long cable when not in use.

Our DC charge module is rated to supply up to 12.5 kW (and in use it comes close to that). It is software upgradeable to 25 kW however I have little need for that given we are on a single phase supply with 63 A breaker and only have 14.7 kW of solar PV spread across multiple azimuths.

It has multiple modes of operation and is bidirectional.

The mode I mainly use is to charge from excess solar and it does a great job of that. It can adjust the power flow faster and with more granularity than AC charge stations (which operate in 1 A increments) and it can also charge at low power levels well below 1 kW if there is not much excess solar. But the great part from my perspective about charge from solar is that all the power is handled via the DC bus leaving the inverter capacity free for the home.

Of course you can if you want use it to charge the car from the home battery and/or the grid.

It also provides V2X capability via the Sigenergy stack, it can use the car battery to power the home, export to the grid or charge the home battery. My main interest in V2X capability is for additional supply during grid outages. I don't propose to use the cars as regular supply points, we have enough home battery capacity for most regular scenarios.

I have tested V2H with both our MG4 (Essence 64 kWh NMC) and MG ZSEV (50 kWh LFP). Works fine.