Please help me understand these numbers.

[LazMan]

Hi. I recently drove from Toronto to Ottawa and back.

It was 20C on the way there and pouring rain on the way back. Wh/km heading east was 168Wh/km on dry roads and west was 178 Wh/km in the rain. The prevailing winds are from the west. Ottawa and Toronto are at the same elevation.


Total distance: 850.7km,
Total energy: 146.9 kWh
Average energy: 173 Wh/km.


I drove non-stop on the way home, 398.4km and had 31 rated left. Total energy use was 71 kWh. Assuming rated is 193Wh/km, then...


Here is my question:

Do we know how much energy is left in reserve? 85kWh = 71kWh (used) + 5.9kWh left (31km) + reserve + battery degradation.

Should I be able to calculate battery degradation or is this actually more complicated.

Thanks.

 

[jerry33]

Should I be able to calculate battery degradation or is this actually more complicated.

It's actually more complicated because:

1. Mapping a battery's SOC uses a lot of estimating.

2. The pack can become unbalanced giving a false sense of degradation.

3. The actual methodology isn't known.

4. The methodology sometimes changes between software versions.