Usable Battery and Percentage Remaining

[southsider]

I've trawled the forum and can't find anything on this (apologies if I've missed it).

I have MG ZS EV Long Range. Battery capacity stated as 72kW. Usable capacity stated as 68.2kW i.e. around 95%.

When the car is fully charged, does 100% charge remaining relate to 72kW or 68.2kW?
Does the car stop when the battery reaches 5% (i.e. when it has used 68.2kW of the 72kW capacity), or could you still be driving when it gets to 1% (if you dare!)

And as the car gets older and the battery degrades, say eventually by 20%, does "100% battery remaining" adapt to that, or would the car run out of juice at 20% remaining?

 

[Gadget Geek]

68.2kWh is the usable battery. There is a 3.8kWh buffer which protects the battery from over charging and draining it dry. It will also hide some early degredation.

 

[southsider]

68.2kWh is the usable battery. There is a 3.8kWh buffer which protects the battery from over charging and draining it dry. It will also hide some early degredation.

Thanks - yes but when the car says there is 100% charge remaining, does that mean there is 68.2kWh remaining?

 

[Kithmo]

Thanks - yes but when the car says there is 100% charge remaining, does that mean there is 68.2kWh remaining?

Yes. If you interrogate the BMS via the OBD2 port the OBD2 reader will show something like 97% or 98% SOC when the car is fully charged and saying 100%.
It will also show something like 3% or 5% when the car shows 0%.
This amount of usable battery between the low figure% and the high% is the 68.2kWh

 

[southsider]

Yes. If you interrogate the BMS via the OBD2 port the OBD2 reader will show something like 97% or 98% SOC when the car is fully charged and saying 100%.
It will also show something like 3% or 5% when the car shows 0%.
This amount of usable battery between the low figure% and the high% is the 68.2kWh

Thanks. I have no idea what BMS and OBD is but I don't think it matters. So basically if the car says you have 1% battery remaining, you could still be driving it? Ideally rolling into your driveway admittedly.

 

[N2STY]

So basically if the car says you have 1% battery remaining, you could still be driving it?

It will be in restricted power mode but you won't be stranded not recommended try and stay away from single digits