OBD to track Battery SOH?

[Dragon Tourniquet]

3 weeks old Macan 4. Mileage = 1831km
Just gotten my OBD. Forgotten to capture a screenshot.
Maximum energy content of the traction battery = 94300Wh
HV battery energy content = 39875Wh

From the vehicle dashboard showing SOC = 46%.
If we calculate from this information, it means at 100% the energy content = 39875/0.46 = 86685Wh.

An if we take the Max = 94300Wh, it calculated that the SOH is only = 92%.
Does this mean that 3weeks, Mileage = 1831km, the SOH dropped 8%.

How to interpret the measurement?

Unfortunately that's not quite accurate, because the SOC displayed is calculated after a percentage of the battery is reserved to keep it healthy. I'm not sure if that percentage has been made public, but previously Audi had been using 5% on the e-Tron.

Sponsored

 

[craz8]

The problem with comparing kwh stored and SOC as a percent is that the SOC is a calculated value, using the voltage of the battery and some clever math to estimate the stored power, where the kwh stored is a fixed amount, but hard to measure directly without taking out that power.

I don't know if you've noticed that the SOC % drops 1-3% as soon as you unplug from a charger and drive away - this is because the charger needs to provide a higher voltage to move the current into the car, so the % calculation gets confused for a short time, and as it works out the actual battery voltage, the SOC drops too.

There's also the problem of the voltage dropping as soon as it's under load, which we've all seen with 12v batteries that can show enough voltage until you use them and it drops enough your starter motor can't get enough current!

So the SOC % isn't an accurate enough number to do this calculation with and get sensible results.

 

[PrudentOcean]

California is considering making the battery SoH information accessible to EV car owners. This would become a requirement starting in 2026. I believe Porsche already has the information and is just not exposing it, so they could provide a software update to display this information on all Macan EVs.

 

[Yves]

Unfortunately that's not quite accurate, because the SOC displayed is calculated after a percentage of the battery is reserved to keep it healthy. I'm not sure if that percentage has been made public, but previously Audi had been using 5% on the e-Tron.

The pack is 100kwh with 94kwh usable energy, that is what officially is communicated, so …
Either Porsche is low balling the content on purpose, and hopefully we get a bump in range after the first update and they have learned to better manage the battery …
Or we have been short sold the real Bruto and Net capacity and we should go to court ?

 

[Mavshyn]

The pack is 100kwh with 94kwh usable energy, that is what officially is communicated, so …
Either Porsche is low balling the content on purpose, and hopefully we get a bump in range after the first update and they have learned to better manage the battery …
Or we have been short sold the real Bruto and Net capacity and we should go to court ?

Hopefully not the last. lol

Sponsored