Car Scanner HVB Energy Reading

[NorthlandPhil]

Charged my car to 90% last night. Below is what I see in Car Scanner. I have 2024 Premium AWD with Extended Range battery. I'm expecting Energy/SOC to be 91 kWh. But it's not. It's only 85.8 kWh. Can anyone explain?
77.22 kWh / .90 = 85.8 kWh.

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[AKgrampy]

I believe you meant you expected 81kWh. Reading is not that far off. My car’s SOC will drop a percent right after starting so I know numbers are not perfect.

 

[JimmyMachE]

Your SOH is still 100%, what is the BECM Battery Capacity in Ah?


Earlier threads on energy at 100% SOC:

https://www.macheforum.com/site/threads/mach-e-extended-range-battery-buffers-and-dcfc-limits.2431/

https://www.macheforum.com/site/thr...of-energy-does-the-battery-really-hold.17694/

 

[NorthlandPhil]

Your SOH is still 100%, what is the BECM Battery Capacity in Ah?

Looks like 278 Ah. Does that look right?

Thanks for the links. I can see this gets pretty messy, pretty fast. Still, I'm curious and I enjoy the math, so I'm going to do some more research and get some more numbers over the next few charges. I'm charging to 100% tonight. I'll see what says tomorrow.

My battery temp is 64.4F, which is below 77F (25C) "standard" temp. That seems to account for some of the difference. I found a chart (not sure its source or accuracy) that shows 88.7 kWh at 65F. My 85.5 calculation is close, but I still wonder about nearly 3 kWh... Not going to lose any sleep over it, but I'm going to dig a little more on this. Mostly because it's fun stuff.

 

[NorthlandPhil]

I believe you meant you expected 81kWh. Reading is not that far off. My car’s SOC will drop a percent right after starting so I know numbers are not perfect.

Oh, I see what you did. I was confused. Yes, 90% SOC of 91 kWh would give an expected energy of 81.9 kWh, where I see 77.22 kWh. Still a bit off, I think.

But what I was doing is working backwards. Given a SOC of 90%, and energy of 77.22 kWh, what would be the energy at 100%? 77.22 / .9 = 85.8.

Anyway, it gets more complicated with temperature a big factor. So, I'm probably in the ballpark...

 

[JimmyMachE]

Yes, and the 278 Ah battery capacity is probably correct, too. We don't know the reference value for brand new vehicles, as this variable appeared quite recently in Carscanner.

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