Real Wold BEV range reduction in a really cold region?

The price of most available BEVs in the US has not come down as much as I wished. BEVs are still expensive compared to conventional cars or even to a plug-in-hybrid like a Prius Prime I now own. Still, I am seriously considering purchasing a BEV this year. The last five years of PP ownership allowed me not only to save some additional funds from fuel and maintenance costs saved but also created a substantial amount of capital gain to increase my car purchasing fund, such that I can now afford a $30K to $35K vehicle. After applying the current fed tax credit and local incentives totaling $9.5K, there are few options of BEVs this year that falls under this price range.

In addition to the affordability issue, I also have to consider the range. The EPA range of many BEVs is getting long enough for most of my needs. Except for the cheapest BEV, LEAF at 152 miles, most others are getting over 200 miles, some reaching 300 miles range. Over 4 years of my daily driving record from the PP suggests, that 95% of my daily drives are less than 100 miles. And if the threshold is increased to 200miles, then 97% of my daily drives are covered. As long as I can use our other conventional car (it is currently Nissan Pathfinder SUV) for the rest of 3% of days I drive more than 200 miles a day, then a BEV with an EV range of 200 miles is completely satisfactory.

One caveat is that this analysis is comparing the number of days only. It does not consider the proportion of the miles driven. The 5 % of the times I drove over 100 miles/day actually represents almost 30% of the total miles driven on the car. Meaning, if I replace the PP with a BEV to be used only for the 95% use cases on a day I drive less than 100 miles, then I am replacing only 70% of the total miles driven. The rest of ~30% miles must be driven by an SUV with a substantial fuel consumption increase.



Furthermore, driving a PHEV (Prius Prime) for 5 years, I know the effect of cold weather on the EV range. The real-life data from my PP suggests that I should expect an almost 50% reduction in the EV range during the worst (coldest) conditions from the best condition during warmer months. In my case for the PP, this represents ~36 miles of EV only drive on the best days in summer and only ~18 miles of EV only miles on the worst (coldest) days of winter. I am still getting EPA-rated 25 miles or better EV range on average.

This effect of cold weather makes the selection of a BEV very difficult. I have to purchase a BEV with at least 100 miles ranges under the worst-case scenario to be satisfactorily used 95% of the time. Or if I want to extend the usability to 97%, then it must have at least 200 miles ranges under the worst conditions.

A recent test by a What a Car? team on 5 well-known BEVs seems to prove the detrimental effect of cold on the EV range. They compared the 5 identical BEVs under the same condition in summer and winter, plus 6 new BEVs previously not tested in Summer. And the result is as follows.

For the winter experiment, the What Car? team put the 500, Taycan, Ford Mustang Mach-E and Skoda Enyaq from the warm weather outing through the same testing procedure in 37-47 degree (3-7 degrees C) conditions, along with six new cars, including the Tesla Model Y, updated Model 3 and BMW iX3.
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Cold Weather Cuts Porsche Taycan And Mustang Mach-E Range By Over 50 Miles, Test Proves
BY Chris Chilton | Posted on March 27, 2022...



The final comment from the author "And it’s worth bearing in mind that despite Britain’s reputation for crappy weather, it rarely gets really cold. If you live in America’s Snowbelt you could be looking at an even bigger performance drop." nails the most important point. In our region, "37-47F (3-7C)" is a balmy temperature in winter. We are talking about the normal low temperature down to teens and single-digit F (-10 to -20F) for most of the winter. So all those BEV owners of the great north, what is like your real-life BEV range reduction in winter?

And I have one more question, the video mentions that due to the heat pump being more efficient than a radiant heating source, cars equipped with a heat pump has the advantage for extending the EV range in the wintertime. That may be true if the temperature is 37-47F (3-7C), but what happens to a BEV with a heat pump when the temperature is 0-14F (-18 to -10C)? Do they usually have radiant heating as well to cover the lower temp? For a PP, that is the time ICE starts running, but for a BEV that option is not available.

 

Yeah, that's an easy part to consider. It would be nice to have a very good cushion. The problem is how to consider the winter range reduction. If the range reduction is expected to be 50% of the summertime and I want a double of a minimum 100 miles EV range even in winter, then I would need a car with 400 miles of EV range in summer. There are very few BEVs that can do that and to me they are unaffordable.

 

No, there are no charging stations that I can use for my ~5% of over 100 miles trips I make. At least for a foreseeable future, if I buy a BEV it will be strictly for commuter use and not for the road trip over 200 miles. This arrangement is fine for me. Especially after the pandemic, our needs and wants for a long trip have drastically diminished. For an occasional over 500 miles/day trip we make, we will use our conventional vehicle.

 

Do you have data on this number "no more than 25%"? As I said, for my PP, I have documented data that in our region the winter EV range reduction is about 50% of the summertime high. Yes, the summertime high for my PP is higher than the EPA estimated range, but I don't know if I can expect that trend for all BEVs.

 

Yeah, my 50% reduction is for a PP running on a very cold day (14F or below) without running HVAC. If I run HVAC on those days, the ICE will kick in and negate the EV mode. On my PP, I get ~35 miles of EV in the summertime, which is a ~40% increase from the EPA-rated 25mile. And I get ~18 miles of EV on the coldest day of wintertime, which is a ~30% reduction from the EPA-rated range. This number may or may not apply to all BEVs.

 

The pip has such a short EV range, such that the percentage can be affected by a very small number of variations. I really don't think your number is way off from mine. The pip has 11 miles EPA-rated range, 14 miles would be a 22% increase and 9.5 miles would be a 14% decrease from EPA. Still, the percentage difference between high and low (14/9.5) is 33% which is more than the 25% you mentioned. Our area is colder than Boston, so that would affect the winter low, I would think.

 

Thanks for clarifying. Yeah, if you are getting only a 14% reduction from an EPA range in a single-digit F temp, then you are doing good. But, I think comparing pip or PP to a pure BEV may not be a good comparison. They have a much larger battery and mostly better BTM. And your number and my number only represent two data points so far. I would love to hear from BEV owners in a cold climate to get a better idea on what the norm for winter range reduction is.

 

I can easily understand that BEVs with a better BTM performing more efficiently in extreme temperature conditions. So, the 50% range reduction in my PP from summer to winter is probably not a good baseline to judge how a BEV performs in winter. But I still would like to know from people who drive a BEV in a cold climate what is winter range reduction is like. If it is 25%, like @bisco said, then my need for 100 miles in winter with double of that range for a cushion can be achieved by 266.7 miles EV range in the summertime. (266.7x0.75=200) But, that number must be dependant on the model and driving conditions, so it is not the absolute number.

OK, this is not the topic of this thread and this may divert the thread to more technical discussions on how cold temperature affects EV efficiency. But, here is a basic question. How is the SOC and kWh from the wall related? I ask this because I haven't noticed any reduction in kWh from the wall charging my PP in winter. So, the same numbers of electrons are going into the battery even in the colder temperature, yet somehow it has less SOC than in the summertime. Why is that?