Battery capacity left inaccurately reported

[minibiti]

Hi,

I have noticed that after a "long drive" (say more than 30 km at least, but more like 50+ km), the reading of the SoC varies between the moment I stop the car and the moment I use it again several hours later.
The typical example is what happened to me yesterday. I left home I had 48% left. When I got back after 30 min drive I had 22% left. But when the car started charging 3h later (via timer), it started with 29% left.
And this is somehow explained by the fact that the battery pack is an analogue thing and that voltages have to equalize between all the cells and so on. So I am not too surprised that it works like this.
But I have 2 questions:
1. Do all the cars have the same behaviour? Or are the other cars better at "estimating"?
2. Does the reading get more accurate as we get closer to an empty battery? Indeed, I know that when the car stops because of an empty battery pack, it does get a few percentage points back after a while and one car hopefully reach the nearest charger. But I am wondering if the inaccuracy is still between 5 and 10% as one gets closer to 0% SOC.

Thanks for the feedback!

[hsa77]

Hi,

I have noticed that after a "long drive" (say more than 30 km at least, but more like 50+ km), the reading of the SoC varies between the moment I stop the car and the moment I use it again several hours later.
The typical example is what happened to me yesterday. I left home I had 48% left. When I got back after 30 min drive I had 22% left. But when the car started charging 3h later (via timer), it started with 29% left.
And this is somehow explained by the fact that the battery pack is an analogue thing and that voltages have to equalize between all the cells and so on. So I am not too surprised that it works like this.
But I have 2 questions:
1. Do all the cars have the same behaviour? Or are the other cars better at "estimating"?
2. Does the reading get more accurate as we get closer to an empty battery? Indeed, I know that when the car stops because of an empty battery pack, it does get a few percentage points back after a while and one car hopefully reach the nearest charger. But I am wondering if the inaccuracy is still between 5 and 10% as one gets closer to 0% SOC.

Thanks for the feedback!

Opplevde dette til stadighet med min R240. Jeg har ikke lagt merke til samme oppførsel på min nye zoe med 40kwh batteri - har jo selvfølgelig noe å gjøre med batteri og bms.