% battery remaining unchanged for 10 miles after charging

[EVsince2016]

On 2 occasions now after a 4 hour overnight charge from ~30-~70% I have driven for around 10 miles before then SOC % changes.

Everything else is otherwise working fine!

Any ideas?

 

[Ian MG5]

Hi I have had this a couple of times after using the rapid charger near me
38% to 80% charge
But it settled down after the first 8 to 10 miles
It would be nice to get 8 to 10 miles on 1% battery
I think it’s just one of those quirks we will have to live with

 

[Ron61]

I've had the opposite happen when it seems to lose a lot of SOC for the first few miles after a rapid charge. It may have something to do with battery temperature and the way SOC is calculated.

 

[EVsince2016]

Anything to do with battery balancing maybe?

 

[mj224]

I've had the opposite happen when it seems to lose a lot of SOC for the first few miles after a rapid charge. It may have something to do with battery temperature and the way SOC is calculated.

The voltage in the battery matches the charger whilst on charge, or nearly anyway. Can only advise from experience with lead-acid batteries, true voltage can only be seen 30+ minutes after a charge. Thus the mileage on the EV is calculated using voltage amongst other values, so will be high until the battery settles down.

My car does the same, I loose 10 miles in the first 3 or miles...

 

[Jomarkh]

Anything to do with battery balancing maybe?

It will only balance at 100% not 70%.
If you change to eco kers3 then it will change the range on the GOM

 

[EVsince2016]

The voltage in the battery matches the charger whilst on charge, or nearly anyway. Can only advise from experience with lead-acid batteries, true voltage can only be seen 30+ minutes after a charge. Thus the mileage on the EV is calculated using voltage amongst other values, so will be high until the battery settles down.

My car does the same, I loose 10 miles in the first 3 or miles...

But my car had been charged for over 3 hours before I set off.

 

[EVsince2016]

If you change to eco kers3 then it will change the range on the GOM

Yes the GOM changes but % SOC shouldn't!

 

[Jomarkh]

Strange

 

[Hairyfool]

To the best of my knowledge there is no 100% accurate measure of battery charge state or capacity "on-the-fly". The closest is coulomb counting but even this has some degree of tolerances. Whenever you switch from charging to discharging there is going to be some overlap of the methods used to tell its state of charge during charge to what it is during discharge. This is going to be even more of a problem once you take into account the number of individual cells involved. In theory the only precise value is 100% after charging and balancing.

When it said 70% during charge that in itself was only an estimate (although better than the GOM). The BMS probably can't report apparent increasing charge levels during actual discharge so it just waits until it hits the next decreasing discharge threshold to report a change i.e. 70% to 69%

I haven't had my MG for long enough to work out its foibles but my leaf would drop from 100% to 99% before I had left our road (1/2 mile) or drop to 99% nearly at the station (3 miles)

 

[EVsince2016]

To the best of my knowledge there is no 100% accurate measure of battery charge state or capacity "on-the-fly". The closest is coulomb counting but even this has some degree of tolerances. Whenever you switch from charging to discharging there is going to be some overlap of the methods used to tell its state of charge during charge to what it is during discharge. This is going to be even more of a problem once you take into account the number of individual cells involved. In theory the only precise value is 100% after charging and balancing.

When it said 70% during charge that in itself was only an estimate (although better than the GOM). The BMS probably can't report apparent increasing charge levels during actual discharge so it just waits until it hits the next decreasing discharge threshold to report a change i.e. 70% to 69%

I haven't had my MG for long enough to work out its foibles but my leaf would drop from 100% to 99% before I had left our road (1/2 mile) or drop to 99% nearly at the station (3 miles)

This never ever happened on my Leaf Gen 1 or 2

 

[lebelinconnu]

On my 30 kWh Leaf in this weather I lose about 5% of battery in the first mile going to work before it seems to settle down. It seems to be a combination of it being uphill and the colder weather causing it, as I then seem to lose about 3% over the next 3 miles (straight/ downhill).

 

[EVsince2016]

On my 30 kWh Leaf in this weather I lose about 5% of battery in the first mile going to work before it seems to settle down. It seems to be a combination of it being uphill and the colder weather causing it, as I then seem to lose about 3% over the next 3 miles (straight/ downhill).

Mine did too, but the 40kw Gen 2 with heat pump didn't do too bad.

My MG5 issue is that it uses 0% in up to 10 miles after a charge!

 

[smokie]

Thinking back to ICE cars (haha) most of those would go quite a distance before the needle went down at all on the fuelometer.

 

[Lucky5]

My 5 did this on a few occasions when it was fairly new. I have not noticed it happening for a while now though so maybe related to BMS calibrating the battery pack in the first few thousand miles?