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A few heat pump complications from someone that considers himself a heat pump advocate.

Capacity: the colder it gets the harder it is to keep up with the heat load as there is "less heat" outside to move inside and your heat loss is going up at the same time, Delta t, or the temperature difference between inside and outside. You basically need substantially more capacity for heating then you do for cooling the same space.

Defrost: you do need to reverse the cycle to defrost the heat exchanger that is outside. Heat pumps work great if your low temperature is 40° Fahrenheit, they struggle when it's just above freezing and raining, the coil ices up all the time and so you waste a lot of energy defrosting it. Meanwhile, you don't want the passengers to get cold so you have auxiliary heat which is basically electric resistive heat in an EV.

Defog: you use the air conditioner to dehumidify the air to defog the windows, at the same time you need heat so that again necessitates auxiliary electric resistive heat.

Cost: larger capacity system, larger components, more refrigerant, controllers and valves for defrost and reversing, it all adds up.

Weight: no big deal in a stationary application but in an EV every pound counts.

Living in the Northeast, I am not opposed to heat pumps in electric vehicles, it's just that it's not the slam dunk engineering trade that everybody seems to think it is.
I think ground loop heat pumps are good choices because they reduce a lot of the problems you mention, but yeah, for heating the cabin of a battery electric vehicle, they are useful in such limited circumstances, that they aren't worth the complexity and cost.
 

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In reality all I really want/need is 170 mile range, the day I trade it in/sell it should still fit the bill. By then there should be a little bump in battery tech.
 

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I have an account, can't link the car to the app, tried all the variations :|

How exactly did you download your data?

Thanks :)
I haven't logged into the my.chevrolet.com website in awhile. Used to be able to get last 12 months of data downloaded. But the option appears to have been removed. I'm only seeing last 7 days and last 30 days.
 

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A few heat pump complications from someone that considers himself a heat pump advocate.

[...]

Living in the Northeast, I am not opposed to heat pumps in electric vehicles, it's just that it's not the slam dunk engineering trade that everybody seems to think it is.
Good to know, thanks for writing that out.

Years ago when I leased a 2012 Leaf I think there was a bit of to-do made over the fact that Nissan improved on it in various ways, including replacing the resistance heater with a heat pump. I live in a temperate climate and indeed at times had to turn off the resistance heater to help make it to my destinations. I do think it was interesting that they made some bit of claimed efficiency improvement in the EV with the change-out of heating methods. For me, my solution ultimately, in an environment that seldom got below freezing, was more to to use the seat heaters, and sometimes just to drive the gasoline car I had to retain for longer distances.

I also learned the lesson you refer to above in that I've had heat pumps on my home for the last 15 years. I would have probably gone with a different solution if it got much colder here.
 

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I haven't logged into the my.chevrolet.com website in awhile. Used to be able to get last 12 months of data downloaded. But the option appears to have been removed. I'm only seeing last 7 days and last 30 days.
Yup, 30 days is the max that I see as well.
 

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Hey Eric, good seeing you active here again.

Request to update this thread with your latest info.
Thanks! I guess I have to start off here:


Thanks to this pandemic, my travel has been curtailed significantly, so I don't really have much of an update since (I've only put another 5,000 miles on).

The TL;DW for the video is that, after 120,000 miles, it appears that my Bolt EV still has well over 90% of its initial battery capacity. After running my data and noting when in the timeline I had my BMS updated, I'm even more convinced now that it was the cause for ~2 kWh of "loss." I put it in quotation marks because I think it has less to do with actual capacity loss than it does with a rewriting of the code that determines how energy used is calculated.

That being said, the degradation I've experienced is noticeable. That is because early on, I got used to my first charging stop being about 200 miles out on fast freeway trips (70 mph average driving speeds). When I had less than 50,000 miles, I could easily do that while still arriving with about 10% to 15% battery. Now, if I try it, I'm lucky to arrive with more than 5% battery.
 

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I have owned my 2019 Bolt LT with 78,000 miles for six weeks. My wife and I took it to a high school football game Friday night located 74 miles from our house. I assumed a 90% charge would be adequate to get there and back. It turned into a range test. The trip was 90% interstate. My GOM said I had 192 miles of range. When we arrived, the battery meter showed 55% charge remaining. Seemed good to get back home since we started at 90%.
When we arrived home we had 5% remaining with the blinking meter saying charge soon. I estimate I had about 10 miles left when we got home. I am disappointed in this range. A 148 mile trip with 10 miles left on a 90% charge gives me 148+10+20=178 mile range if I could charge to 100%(presently software limited to 95%). This is less than 75% of the original 239 mile rated range. I know this was mostly interstate, but still disappointed.
I don’t know the charge history of my car, but it appears to have been used for Lyft. Has anyone else experienced this disappointing range? I will be glad to get new battery modules since mine is an Oct 2018 build. I hope to get 258 miles of range with them. I only hope they perform better than 75% when they have 78,000 miles on them.
 

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...... I am disappointed in this range. A 148 mile trip with 10 miles left on a 90% charge gives me 148+10+20=178 mile range if I could charge to 100%(presently software limited to 95%). This is less than 75% of the original 239 mile rated range.....
...... I will be glad to get new battery modules since mine is an Oct 2018 build. I hope to get 258 miles of range with them. I only hope they perform better than 75% when they have 78,000 miles on them.
An interesting account. My 2017 Bolt EV only has about 33k on it, so I still have about 230 miles of summer range left down from the original 238. The range will be worse if you use the A/C. With A/C I have about 205-210 miles of range. All calculated on full charge. Of course, with heat in the winter it all collapses by at least 25% or more. I barely have 150 miles of range in the winter.
Indeed, I am looking forward to the new battery too!!
 

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I have owned my 2019 Bolt LT with 78,000 miles for six weeks. My wife and I took it to a high school football game Friday night located 74 miles from our house. I assumed a 90% charge would be adequate to get there and back. It turned into a range test. The trip was 90% interstate. My GOM said I had 192 miles of range. When we arrived, the battery meter showed 55% charge remaining. Seemed good to get back home since we started at 90%.
When we arrived home we had 5% remaining with the blinking meter saying charge soon. I estimate I had about 10 miles left when we got home. I am disappointed in this range. A 148 mile trip with 10 miles left on a 90% charge gives me 148+10+20=178 mile range if I could charge to 100%(presently software limited to 95%). This is less than 75% of the original 239 mile rated range. I know this was mostly interstate, but still disappointed.
I don’t know the charge history of my car, but it appears to have been used for Lyft. Has anyone else experienced this disappointing range? I will be glad to get new battery modules since mine is an Oct 2018 build. I hope to get 258 miles of range with them. I only hope they perform better than 75% when they have 78,000 miles on them.
How fast were you driving on the interstate? There's a direct relationship between higher speed and lower range for EVs, Bolt included.

Here's an analysis that estimates somewhere around 160-170 miles (100%) at 80 mph:

Here's discussion about the Bolt's range on the highway vs city:

And here's a study about the Bolt's loss of range over time:
 

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I am disappointed in this range. A 148 mile trip with 10 miles left on a 90% charge gives me 148+10+20=178 mile range if I could charge to 100%(presently software limited to 95%). This is less than 75% of the original 239 mile rated range. I know this was mostly interstate, but still disappointed.
You didn't mention the speed at which you traveled, if it was 70MPH or more then you should expect significantly less than the EPA rated range. The same with winds - you'll find that a good wind from any direction hurts on a round trip because you loose more in a headwind than you gain in a tailwind. HVAC usage and ambient temperatures can also have significant impacts on range.
 

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You didn't mention the speed at which you traveled, if it was 70MPH or more then you should expect significantly less than the EPA rated range. The same with winds - you'll find that a good wind from any direction hurts on a round trip because you loose more in a headwind than you gain in a tailwind. HVAC usage and ambient temperatures can also have significant impacts on range.
Thanks for all the info. I drove between 70-75 on the interstate.
 

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Being generous, I will assume you have 55 kWh usable left in your Bolt.

85% of 55 kWh = 46.75 kWh

148 miles ÷ 46.75 kWh = 3.17 mi/kWh.

If you were driving at 75 mph, with the AC on this is exactly what you should expect.
My wife’s Model 3 gets 87% of rated range on the interstate. I was expecting something close to that. My Bolt is getting 13% less range from rated than my wife’s car. You may expect this, but I have higher expectations. I shouldn’t have to drive 45 mph with the air off to get rated range.
 

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I shouldn’t have to drive 45 mph with the air off to get rated range.
The Model 3 is the most aero car on the road. The Bolt is a short. tall hatchback. Different cars for different uses. Get a Model Y. It will meet your expectations.
Driving the speed limit has many benefits. Try it.
 

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To be fair, my range GOM said 192 miles at 90% charge. I got 160 =83%. Not that unreasonable for 72 mph. I guess my biggest disappointment is that I appear to have actually lost 11% of my original range in my 2 year old Bolt. 90% of 239 is 215 miles vs my apparently accurate 192 miles.
 

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The other realization I have from this experience is that the Bolt is barely adequate as my regular car. Based on this experience, I now have to limit my travel to one hour from home if I expect to make it back without charging. That will get better as more chargers are added, but this one hour range barely meets my expectation of a regular car.
 

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The Model 3 is the most aero car on the road. The Bolt is a short. tall hatchback. Different cars for different uses. Get a Model Y. It will meet your expectations.
Driving the speed limit has many benefits. Try it.
I know. I know, but it is so boring. Haha
 

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The other realization I have from this experience is that the Bolt is barely adequate as my regular car. Based on this experience, I now have to limit my travel to one hour from home if I expect to make it back without charging.
You'll get a significant range boost if you drive a little slower. Find a nice semitrailer that's going 60 to 65 to tail.
 
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