B250e Battery Questions

[Dillmiester]

Hey Everyone.

I’m new to electric cars and picked up a 2017 Mercedes B250e a few months ago. I’ve got a couple of questions.

First off, how does the battery range get affected when the temps drop? Is it mainly because of the use of heating or just the cold temp itself? What’s the sweet spot temp for getting the most range?

Also, what's the deal with the battery capacity? Is that 28kWh the real size of the battery, or just what it can hold when fully charged?

And one last thing - how does the range plus feature work, and how much juice does it actually use up?

Thanks in advance.

 

[J0hnsHere]

Hey!
1. Yes, cold temperature can significantly affect your batter range (both the use of heating and the cold itself);
2. 28kWh refers to the total capacity of the battery when it is fully charged, but the usable capacity is less (battery management systems that protect the battery from being completely drained or overcharged);
3. I really don't know how to help you on this one. Sorry!

 

[lensovet]

Range plus just makes more of the battery capacity available for charging. I think the normal usage is 80% of the battery and range plus uncaps another 10% on top of that. 28 is the usable capacity before range extension, not the total capacity. The total capacity is 36 per this article. Tony posted in this forum that extended range uses 31.5. So standard charge is 78% and extended charge is 87.5%. So my memory was close to reality.

 

[asavage]

Cool weather (below around 50°F ?) triggers the HV battery heater to turn on, which is a several kW power draw all by itself. Even if you forgo cabin heating, that battery heater alone will cause a reduction in range. But the cabin heater is a major power draw as well, if you use it. A/C, not so much.