How big is the MG ZS EV battery?

[tony powell]

I recently charged my MG ZS EV long range to 100% using a type 2 connector. It performed well, charging at 10 kWh. The charge started at 29%, and when full, Endesa informed me that I had used 52.89 kw. So dividing by 71, and multiplying by 100 gives a figure of 74.5 kw. Is the battery really that big?

 

[al6195]

I suspect this is related to my question from this morning, i.e. the charging efficiency is not 100% and the car may turn on the battery heater or fan for part of the charge.

The usable battery is 68.3 kW so you will have started charging with about 19.8kW in the battery and ended up adding about 48.5kW to your battery. The remaining 4.4kW (~8% of the electricity used) is lost or used by the car

 

[hmadsen]

I agree wirh al6195, there are always losses when you charge, this is also why you will sometimes hear a fan or pump start while charging, because it is cooling the battery because it heats up and energy lost to heat is energy not going into the battery

In reality the battery is supposed to be 72 KWh, but they reserve the 4 KWh so that when your car says 100% it is only charged to maybe 98 and when it says 0% it is in reality 3%

This is because fully charging and fully discharging the battery is not good for the car.

They also reserve a bit of this to give you, as compensation for battery degradation...The battery will lose most capacity in the first year, so to mask this, they save a bit of headroom that they can release so that you will not be alarmed, if the car suddenly has lost relatively much capacity in the first year.

All car manufacturers do this nowadays.

I just ordered a tesla, it has a 79 KW battery, but on paper it "only" has 75 KW "usable capacity"

 

[Kithmo]

10% off your 52.89kWh for losses = 47.6kWh actually put in.
29% of 73kW capacity = 21.2kWh.
47.6 + 21.2 = 68.8kWh capacity.
BMS allows charging to approx 95% capacity, 95%of 73kWh = 69.4kWh max you can put in.