Canbus and PID for the IPace

[Maxwell_400]

Here you are:
Feb 14 logs.zip

Unfortunately we are in the middle of a cold air wave from Russia so temperatures here are a kind of low too. Also, to get from Rome to Viterbo (the logs are referred to a roundtrip between the 2 cities) I passed nearby Vico Lake which has an altitude of more than 500 meters and that didn't helped in keeping high the temperatures. I added to the 2 logfiles the extended PID structure with names and formulas for your reference.
As soon as the temperatures will recover I'll get more that if need, just let me know.

Thanks! I need to do some paid work, but I will try to find some time during the evening.

[iomagico]

It seems like if we have access to Pathfinder, that would be a great source of info...
So 4901, 4909, 490E, 490F are not Voltage for Row#1,#2,#3,#4, but they are Voltage of the battery....
Thanks for the info, Steve

No way to have “row” voltages because the battery pack is in the 108S4P, so we have 4 paralleled cells (same voltage) and 108 connected in series.

[Maxwell_400]

Some data from today trip. I focused on the PID in 7E4 that we don't know what htay meassure:

As usual, ideas ?

Hi kermit68, excellent data, can you upload the logs in a zip file ?, I want to look at 4912 and the internal resistance of the battery pack versus temperature.

I was planning to look at it but unfortunately the temperatures dropped again below -10.

Here you are:
Feb 14 logs.zip

Unfortunately we are in the middle of a cold air wave from Russia so temperatures here are a kind of low too. Also, to get from Rome to Viterbo (the logs are referred to a roundtrip between the 2 cities) I passed nearby Vico Lake which has an altitude of more than 500 meters and that didn't helped in keeping high the temperatures. I added to the 2 logfiles the extended PID structure with names and formulas for your reference.
As soon as the temperatures will recover I'll get more that if need, just let me know.

Here is the internal resistance, about 50mOhms for the entire pack, one single cell will then be 50x4/108=1.9mOhms

My battery at -12degC : 5mOhms
kermit68 at 4degC :1.9mOhms
Manufacturer claim at 25degC: 1mOhms

[Maxwell_400]

Hi kermit68, excellent data, can you upload the logs in a zip file ?, I want to look at 4912 and the internal resistance of the battery pack versus temperature.

I was planning to look at it but unfortunately the temperatures dropped again below -10.

Here you are:
Feb 14 logs.zip

Unfortunately we are in the middle of a cold air wave from Russia so temperatures here are a kind of low too. Also, to get from Rome to Viterbo (the logs are referred to a roundtrip between the 2 cities) I passed nearby Vico Lake which has an altitude of more than 500 meters and that didn't helped in keeping high the temperatures. I added to the 2 logfiles the extended PID structure with names and formulas for your reference.
As soon as the temperatures will recover I'll get more that if need, just let me know.

And nominal capacity;

[Maxwell_400]

And finally, I think I know what pid4912 is, just need to do some calculations to reveal it.

[kermit68]

And finally, I think I know what pid4912 is, just need to do some calculations to reveal it.

I was looking at my data on pid 4912 and I pretty sure it's a voltage as for my last trip there is the negative peak when I used the full 400HP of the car for an overtake exactly as I see on the other voltages. Still to be cleared what kind of voltage is as I does not look as the full battery pack one.

[kermit68]

Here is the internal resistance, about 50mOhms for the entire pack, one single cell will then be 50x4/108=1.9mOhms

My battery at -12degC : 5mOhms
kermit68 at 4degC :1.9mOhms
Manufacturer claim at 25degC: 1mOhms

Next weekend we should be around 15C or more, I can take more data at a much higher temperature. so maybe we can draw a curve of internale resistance vs temperature to fine tune the battery capacity.

[kermit68]

And nominal capacity;

The plot is strange ... first it goes a lot over the maximum nominal capacity and second it looks that some data have not been plotted correclty vs time. What formula are you using, so I can check on my other trip logs ?

[Maxwell_400]

And finally, I think I know what pid4912 is, just need to do some calculations to reveal it.

I was looking at my data on pid 4912 and I pretty sure it's a voltage as for my last trip there is the negative peak when I used the full 400HP of the car for an overtake exactly as I see on the other voltages. Still to be cleared what kind of voltage is as I does not look as the full battery pack one.

Send you a PM for the code.

I think it is the Coulomb counter, integration of current over time. The battery pack store energy as 3.6Volts x Ah. Energy is found as 3.6*108*Coulomb counter/xx. If I take the current and integrate over time it matches this value perfectly, the advantage with this counter is that it is much smoother.

It is like the fuel consumption indicator on an ICE car, fuel pressure times injector dwell time. However it will not be 100% perfect, you need to look into the tank or at the fuel gauge to see how much energy is left. This also happens with the I-Pace, sometimes it recalibrate itself and you can see the SOC has changed value even if it has been unused.

And for the SOC the car uses this counter and the voltage to give an estimate of remaining energy. A side effect is that the car may report a few percent SOC but it is very close to empty, the last few percent may disappear quite fast.

[iomagico]

And finally, I think I know what pid4912 is, just need to do some calculations to reveal it.

I was looking at my data on pid 4912 and I pretty sure it's a voltage as for my last trip there is the negative peak when I used the full 400HP of the car for an overtake exactly as I see on the other voltages. Still to be cleared what kind of voltage is as I does not look as the full battery pack one.

Send you a PM for the code.

I think it is the Coulomb counter, integration of current over time. The battery pack store energy as 3.6Volts x Ah. Energy is found as 3.6*108*Coulomb counter/xx. If I take the current and integrate over time it matches this value perfectly, the advantage with this counter is that it is much smoother.

It is like the fuel consumption indicator on an ICE car, fuel pressure times injector dwell time. However it will not be 100% perfect, you need to look into the tank or at the fuel gauge to see how much energy is left. This also happens with the I-Pace, sometimes it recalibrate itself and you can see the SOC has changed value even if it has been unused.

And for the SOC the car uses this counter and the voltage to give an estimate of remaining energy. A side effect is that the car may report a few percent SOC but it is very close to empty, the last few percent may disappear quite fast.

4912 is an energy counter (maybe the only one).
To find the right divisor we have to drive the car till it stops.
For my counting (to be double checked) I am using this formula
PID4912 —-> (256A+B)/100
Estimated energy from bms ——> ([224912]x3.6x108)/1600expressed in kWh