EV Range degradation

We were getting about 35 miles (~55 km) EV range last winter in Michigan. Cold weather does that.

 

I suspect temperature is the dominating factor. We have been getting 58-62 mile EV ranges all summer, along with temps that have continued here (North Carolina) mostly in the 80's and 90's. We are expecting a sudden drop in temps here, and I expect the range to soon drop significantly to levels that we experienced in the winter and early spring.

 

Everyone address colder temps already so I'll touch on the Winter Tires. I'm assuming the winter tires are not the low resistance tires that were originally on the car. More resistance = less efficiency = less range.

 

Yes, cold weather. I was shocked how much reduction in EV range when the temps dropped into the low 50s a while back. It's back up to 70 miles that the temps are in the 70s.

 

It is not just about weather. Despite the temperature range in my area hasn't changed too much, I have noticed a big swing in EV range due to traffic conditions. If I sit in traffic a lot, I get much higher EV range. If I get to drive above 50mph consistently, I get much lower EV range. My EV range goes from low 50s to 65 miles on a full charge. The EV range is a prediction and it learns from your previous drives to come up with the latest number. So if you sat in traffic, it should come up with a higher number the next time you charge. The car seems to like traffic.

 

I was shocked at how much range we lost. We got at best 98kms and now we’re seeing ~63kms and that’s at 5C but above freezing.

 

Tesla says its cars are most efficient at 23 mph so if you are in traffic, your average speed is probably somewhere around there. Unlike ICE cars, there is very little energy loss when stopped (unless you're running the HVAC). Highway speeds lower your EV range due to increased wind resistance.

 

Now that it's just above freezing temperatures lately, our range has dropped to upper 60's km with the heater burning off the kWh.

 

That's the EV range we were getting last winter. Starting in ECON Mode causes the Clarity PHEV to use the seat heater to avoid the big hit from the resistance heater, so I stick with that unless my breath starts fogging up the windshield. A heated steering wheel would be nice.

Edit: I forgot to attribute our snow tires to some of our reduced EV range.

 

One other seasonal factor I've noticed that is neither temperature nor snow tires is rain. We don't get snow here, so the tires are the same year round, but we get a lot of rain, and the highway-speed EV range on the Volt I had previously decreased noticeably if it's raining a lot versus a dry road, even with the climate control turned off. I haven't had the Clarity through a rainy season yet, but even with the first few rains of the year the decrease in range was noticeable. I assume this can be attributed to the combination of higher rolling resistance and higher aerodynamic drag from the wet surface. There's also the windshield wipers, but that's probably a small load unless you're stuck in traffic for a long time.

For me this is the winter when it's also colder, so the inefficiencies compound, but I assume in most areas the rain would tend to be in the summer and if anything would result in a little less climate control load.

 

Have not changed driving habits (75 mile round trip work commute and I do not charge at work). Clarity would religiously charge between 47 and 52 EV. Now a sudden drop to upper 30’s for a 100% charge and combined fuel economy has also dropped a ton. I’m in Minnesota. Is this simply weather related or should I have the car looked at? (Got the car 3 months ago about 4000 miles on it)

 

I too am seeing significantly lower EV range and it is not even that cold yet. (Last night it was in the 40s (F) and I was only able to charge to 38 mi. on my L2 charger at home. How low will this go when it really gets cold here in Massachusetts? Will anything in the battery/charging update change these EV ranges?

 

It also has to do with you previous driving. You get less EV miles on the highway than during local traffic. So if you drove with EV on the highway recently the car will predict lower EV miles going forward because it thinks you will be doing that again.

 

To those seeing a big reduction in EV range in the mornings, where do you park at night - outdoor or an unheated detached garage? The cold night time temps will chill your battery making less efficient.

I have the Canadian model with battery heater and also park in an attached garage. With nightly temps around 5 C, I've seen my EV range around 80-85 km in the morning after a full charge compared to a max of 96 km over summer.

So far, I've not noticed the battery heater coming on after a full charge.

 

I park in an un-heated garage but the temps have been in the 40’s and 50’F mostly at night. My driving habits have been extremely consistent so have ruled that out. As I do a 75 mile commute 4 days a week and don’t charge at work my battery is completely depleted when arriving home. Several charges a week ago I strangely achieved 99% of a full charge according to the Honda app with estimated ev miles being between 36 and 40. This week I have been achieving 100% charge but only 39 mile estimated ev range. Proof at the pump confirmed I’m losing efficiency by leaps and bounds. A month ago I was averaging around 110 mpg and now I’m mid 80’s. This average includes using only electric mode on non-work days for errands. Have been using the heater on way to work but generally not on way home. Have refrained from using heater to see if that made a difference and didn’t notice anything immediately observable. Again.... a month ago, estimated ev range was never below 47 after a full charge and was almost always over 50. Then dropped to upper 30’s almost instantly.


Sent from my iPhone using Inside EVs

 

I also noticed some ups and downs in EV range during the summer. Some of it was mystifying. I thought something was wrong but then the EV range went back to "normal" (about 50 miles). I think there are several factors that affect EV range.

Now, with the colder temps, I'm already down in the mid 30-s (miles) and I know it will drop further to the mid 20s once we get into the depths of our Minnesota winter.

 

How are you guys regularly monitoring your range? I just bought the Clarity two days ago and still trying to figure out the best information screens to use on the instrument panel and the main screen. For now I have the main screen showing the Energy flow screen which shows the EV and HV ranges. I still haven't decided on what to put on the instrument panel.

 

This has always been my default instrument panel display and I find it the most useful of the options.

IMG_20180514_085449 by Rajiv Vaidyanathan posted May 15, 2018 at 12:43 AM