EV Charging dropped from 33 to 27 miles

That could be due to some of us having provided an answer to the same question so many times, we let others take over. It's a common issue with posts online. You grow tired of the repetition.

I have seen my estimate change dramatically shortly after the driving situation changes. It's no big deal, which is why the ESTIMATE gets dismissed so easily. Just focus on ACTUAL instead.

Here's video of my 2 most recent drives. Notice how one delivered 31 miles of EV and the other 27 miles, yet both are totally within expectation for each situation.

 

I have experienced a drastic reduction in my EV miles. I use to get 28 to 29. Now over the past month it has got to 22.6. My over all 38000 miles I average 102 miles. Going down fast.
Do I have a bad EV battery?

 

That's very normal behavior of any EV including PP. When the weather gets cold, the EV efficiency drops. For PP, the EV range displayed is just a guess from the previous history of your EV mode drives. If it got cold and started using heat, the estimated EV range on the GOM (Guess-O-Meter) as well as the real EV range will drop. For your reference, in my New England climate, the summer peak best EV range of ~35miles will drop to less than 20miles in winter. You will not see much improvement until next spring.

 

Welcome to PC. As @Salamander_King already explained, you're just experiencing the universal decrease in battery capacity and power that happens to all EVs in every northern winter.

I am puzzled, though, by:

Can't figure out what it means.

 

He has 2019 PP. My guess is ODO reading 38000miles and the lifetime MPG displayed is 102mpg.

 

The efficiency of your gasoline cars dropped with the cold weather too. It is just worse with an EV because you don't have a wasteful engine making extra heat for the cabin.

 

ok, thanks. So its normal 26.5 EV miles.

 

I'd say that in your climate for this time of year, 26.5 miles is better than usual. And of course, it's all hugely dependent on speed and traffic flow.

 

It never gets old does it? *The EV Estimate thing !!

I just got our Primes Estimate back up above 30 again, after the misses had it down below 24. grrrrrrr brrrrrr !!
I wasn't easy either, let me tell ya. experimentation !

 

Yeah, my experimentation on my 2017 PP resulted in GOM showing 48.7miles in the middle of winter (Jan 23 to be specific) with winter tires on at temperature 16F.

I traded the car right after this, and have not experimented with my newer PPs to show better GOM miles. My current PP is showing ~30 miles on GOM that is about 5 miles drop from last month.

 

Right!
Our plugin (EPA 54 miles) easily does 65+ miles. But 22°f average winter Temps? 50 miles. If driving like the typical Bat Out of Hell person? Winter would probably be only 40 miles.
Petrol or electrons - both less efficient the colder it gets because more energy is necessary to overcome cold.
.

 

All the little things like stiffer grease needing time to warmup and lube more efficiently. And cold rubber to warm, much more noticeable in a Tractor Trailer after sitting overnight on a snow covered dirt truck stop, than is a car.

There has to be at least one or two things in a car that are more efficient in extreme cold than at 80° F

 

The engine cooling system, air conditioning, and maybe electronics.

 

The first 2 are interesting from a work load perspective. The electronics in cars have to be made extra heavy duty to withstand the vibration and both high, low ambient temps.
I'm still drawing a blank on low temp efficiency, and wondering if there is a new or old engineering specialty dedicated to low temp efficiency, besides in the basements of NASA. I'll have to look into that and thanks for the reply, as I wouldn't have thought about it again, without your input.

 

That is exactly the reason. The viscous drag of the air is proportional to the square of the speed, and your EV mileage will get much lesser and much lesser as your speed increases.

It also increases with the density of the air, which increases as the temperature decreases. The heater also consumes a lot of energy—more so if you set it much higher than the ambient temperature. It shouldn't be set to higher than 68 °F in the winter.

Also, the gravity is a huge factor. If there is a change in the elevation, your EV mileage will change substantially.

 

This is not directly related perhaps, but lately in my 2019 Prime, the sum of my instantaneous estimated mileage and the the miles driven is dropping as a drive, when this sum used to remain fairly constant to the original estimated ev mileage when I started out. I am not using AC or heat. Could this be the effect of wind resistance or something else?

 

Colder weather easily plays into EV range. You can do Grill blocking, and raise tire pressures to compensate
.

 

It could be headwinds, wet roads, hill climbing, coarser pavement, cold temperatures, etc. Or even just higher driving speed. Anything that makes the current energy consumption higher than the recent average history that is used to make the range remaining estimate.

My non-plugin Prius has been occasionally doing the same thing with its gasoline Distance To Empty gauge over its entire life, whenever driving conditions become less favorable than the recent past. The concept is the same, whether it is using gasoline or battery.

 

By "sum" is constant to the original ev mileage, do you mean the total EV range when the traction battery was full is equal to the sum of the EV range displayed for the segments you drove before recharging?

Hypothetically, at 100% SOC, say GOM was displaying 30 miles. Then after a 7.5miles drive on the EV, the battery is showing 75% SOC and the GOM was displaying 22.5 miles, then another 7.5 miles EV drive, 50% SOC showing 15 miles GOM range, again another 7.5 miles EV drive at 25% SOC showing GOM 7.5 miles, and final 7.5 miles EV drive at 0% SOC, the GOM shows 0 miles. This would be a perfectly linear reduction of EV miles in relationship to the SOC left in the traction battery. Thus the "sum" of each segment of the trip from 100% to 75%,75% to 50%, 50% to 25% then 25% to 0% would equal the total EV range. If I understand it correctly, you use to see the "sum" of each segment of the EV travel came to be close to the total EV range, but now it doesn't?

I don't have solid data on this for my own use case, but I have never seen a perfectly linear capacity loss during the entire EV range. If I am driving a completely flat road at a constant speed without traffic, then, maybe the EV range loss is close to linear to the SOC left in the traction battery. But my usual drives involve uphill, downhill, traffic stops, and speeds above 50mph and under 15mph. And yes, consider the wind directions and strength... there is no way that each segment of the EV travel will result in a constant EV range. But still, if you are driving the same route every day with a similar driving habit, then the overall average will be fairly constant except the environmental changes such as temperature and road surface conditions.