Consumption figure (kWh / 100km) number is not updating

[MarkHoward]

Last couple of days the power consumption number (since last charge) is not updating.
I'd normally leave this for a few days to get a better handle on it, but I'm going to really need that figure during a long trip planned on Sunday.

Has anyone else come across this?
It is stuck at 29.8 kWh / 100km, within a km of leaving home, after a charge, and would normally come down to 19-20 over the next 3-4 km (town driving): but doesn't change at all.

 

[Coulomb]

It is stuck at 29.8 kWh / 100km,

That's a magic number, a maximum above which never seems to get reported.

I guess it's time to reset the trip meters (both of them). I don't know the MG4, but I assume that will start the usage calculation from scratch (discard historic information about some long hill climb, for example).

 

[MarkHoward]

Ah ... but this 29.8 number is supposed to be "Since last charge". That would have been immediately before I took it out of the garage this morning after its charge last night. That charge should have reset it - so, no "long hill climb" in its history.

 

[DixieTGS]

So the implication is something used traction battery power between the end of charging and next driving the car:
Intelligent battery heating turned itself on?
Scheduled battery heating?
Aircon turned itself on somehow?
Knackered 12V battery trying to be recharged or loose terminals?

None of the above seem very likely but worth checking if possible.

If the charge finished at a a set SOC (80 or 100 typically), is it still at that value as you start to drive? If no it confirms something is really using the battery.

If yes then the max that could have been used is 1%, and you could do a rough calculation to see how many miles plus 1% (0.6kwh) you need to drive before it should drop below 29.8 and see if that tallies with reality.

 

[MarkHoward]

Thanks Dixie.
I have found that, as you suggested, the Intelligent battery heating had been turned on.
I guess I had thought that that would only activate when the car was "on". Maybe not.
Still not sure what the recommendations are regarding the use of intelligent battery heating.
I find it difficult to find stuff in the user manual with no index.

Anyway, I've turned it off and will see how that affects the consumption figure.

 

[DixieTGS]

I believe the consensus for UK temperatures is basically to leave it switched off. Its main use is to achieve higher charge rates on DC chargers when less than 10°C. Ideally it would be active for a while just before you reach the charger.

Pre-heating the battery from the app or on a schedule however can improve efficiency at the start of a journey if it has been cold overnight.

You can find lots of threads which mention intelligent battery heating and Pre-heating using the search forums feature and limiting the search forum to just MG4.

 

[Kithmo]

I've noticed the "From last charge" figure on mine didn't update a couple of times after charging, most of the time it does.

 

[siteguru]

I recall this happening once, but only once.