MG4 trickle charging

edcquintana

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MG4 SE SR
Hi all,

Has anyone been able to get more than 1kW when using the granny charger? I’ve tested multiple different power outlets and couldn’t get more than that. Convinced there was something wrong, I took the car to the dealer and they tested my car against another brand new MG4 and that also came back with 1.1kW. Seems awfully low?

For context I have the MG4 51kWh.

Thanks
 

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Mine charges between 2-2.5kW. Max setting on car and 16A extension cable. Are you plugging the charger directly onto a 13A wall socket?
 
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Mine charges between 2-2.5kw. Max setting on car and 16a extension cable. Are you plugging the charger directly onto a 13a wall socket.
Correct it’s onto your usual wall socket. However, I’m using the cable provided by MG. Perhaps it suck? It says “Rated current: 8a” i’ll try to attach a photo
 

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In principle 8A should give you about 1,8 to 2kW.
Is there something else that could drain current during the charge (heater, battery heater, etc)?
 
In principle 8A should give you about 1,8 to 2kW.
Is there something else that could drain current during the charge (heater, battery heater, etc)?
Would you know if the battery heater is turned on by default? I don’t think I ever changed that. But also I’m in New Zealand and we’re in summer here, not sure if the car would be preheating the battery anyway?

That said, a mate of mine lent me his Kia EV6 granny charger (10A) and I remember getting 1.3kW which was slightly better than my MG cable.
 
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Hi all,

Has anyone been able to get more than 1kwh when using the granny charger? I’ve tested multiple different power outlets and couldn’t get more than that. Convinced there was something wrong, I took the car to the dealer and they tested my car against another brand new MG4 and that also came back with 1.1kwh. Seems awfully low?

For context I have the MG4 51kwh.

Thanks
You mean they tested the other showroom mg4 with your granny charger?
If so, and both are only getting 1.1kW, it seems to me either your granny charger is defective, or incorrectly set to a lower amp rating.
What is the granny charger normative in your country? In the UK it’s 10amp, giving a draw of around 2.2 kW and supplying the battery with around 1.8 to 1.9 kW.
It seems yours is configured for 6amp draw which would show 1.1kW in the car accounting for losses.
 
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If you go in the battery management, in the car's interface, where you can see the consumption, down on the centre left you have a button to activate or not the battery heater (preconditioner).
I don't know if you have it in the 51kWh version, but if yes, it can be activated without knowing it.
10A on a 230V grid should give you a maximum of 2,3 or even 2,4kW and 8A around 1,8 to 2kW.

What was your battery state of charge when you got 1,0 - 1,1kW?
 
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If you go in the battery management, in the car's interface, where you can see the consumption, down on the center left you have a button to activate or not the battery heater (preconditioner).
I don't know if you have it in the 51kW version, but if yes, it can be activated without knowing it.
10A on a 230V grid should give you a maximum of 2,3 or even 2,4kW and 8A around 1,8 to 2kW.

What was your battery state of charge when you got 1,0 - 1,1kW?
It’s all in the picture: the battery heater is a red herring. the heater would be off with 19°C outside temperature. And the state of charge shows 61%.

This points to the granny charger being limited to 6amp.
 
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I'm in NZ also, and mine direct into a 10amp socket only gives me 1.2kW max. Goes between 0.8kW and 1.2kW, does not matter what setting I have it on.
 
I'm guessing that the rest is going into running computers, pumps, etc and the variable part would be charging the auxiliary battery.

At the start of a charge, when you are most likely watching it, the auxiliary battery would be charging, accounting for 100-200 W.
 
I have tested some on my car. When on the 8A setting on the granny charger, it really draws 7,9A from the wall. That is about 1,7 kW, since the grid power was right under 220V that day. Then the car display showed 1,2 kW into the battery, so 0,5 kW lost. It was cold that day. When the car show 1,2 kW we don't know how that is measured. It could be that is it 1,200 kW, 1,249 kW or it can even be 1,299 kW. So it can be a bit lesser loss than 500W. I would guess it is not completely accurate, since when I try 10A charge I get a loss of only 300W and on 15A it is 600W loss. All the test within minutes of eachother, so same temp, SoC and so on.
 
I am changing my SE SR right now at home using the granny charger and the app says 1.8kwh and this is confirmed by the smart meter.
 
I'm in NZ also, and mine direct into a 10amp socket only gives me 1.2kW max. Goes between 0.8kW and 1.2kW, does not matter what setting I have it on.
is this while the HVAC is on? What’s the outside temp? What’s your max Amp setting on the charger?
 
People are granny charging their cars and not locking them so everything turns off (as much as possible)?
 

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