Internal resistance at lower SOC and colder battery temperatures

[Yves]

So yesterday my battery was cold at 9C and had to run some errands … so slowish normal driving and had around 18kwh/100km consumption and no heater running but my percentage was dropping faster then anticipated so this got me thinking that internal resistance is a factor of battery temperature and SOC …

I started a conversation with ChatGPT about this, my initial question:
- Give a table of internal resistance of an EV battery from 0 to 40C and at a SOC of 75% 50% and 25% make a chart as well.

Refining it further for Macan EV and 800v and pack level resistance:

So both SOC and temperature have a meaningful impact on range, which makes it all the more important you can pre condition the battery before and during a trip … it helps with efficiency, fast charging and lifespan of the battery …
I do realize this is a theoretical observation but my experiences align … take it for what it’s worth

So the 20 to 30% drop can be partly alleviated with a warm battery …

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[Yves]

In other words, at 23kw power you loose about 2% more energy, going from 25C to 10C battery temp, which taking everything in consideration is not that much in comparison to the heating and air resistance you have, but every bit of optimization helps
(more when accelerating due to higher power demand, it’s exponential)