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Discussion Starter · #1 ·
Winter has sprung early and I'm seeing the impact the heating system has on power utilization.

It surprises me that 25% of my in-town energy usage goes to heating the car; that seems disproportionate considering the other 75% is whipping my 3,500 pound car around the city.

Is this typical of others/other EV experience?
 

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I live in the SW USA. I do not believe that I would have chosen a Bolt or ANY EV, if I lived in the extreme north. I actually am totally amazed that many Canadian drivers are happy with and manage the Bolt in that environment. When one realizes that the Bolt will heat and cool its battery system, on its own directives, you also realize that you cannot save all the juice by doing without heating for the passengers. In central NM, I have been able to drive without heat. I condition the car, prior to exiting on a 17 degree high desert AM. But, when I leave, I do not use the heat. The rising sun and temps will soon balance out in the AM, and become a big plus in the PM.

I am in the process of taking my wife to Albuquerque for infusion treatment, thus the calculation is critical. I thought that I would have to stop at one of the rare DCFC units in that city. But, not using the passenger heat, driving 55 at 17 degrees on the 83 mile trip to the hospital, has allowed me to make the return trip, in the heat of the day, say 45 degrees, at 75+...all 166 miles, with about 45 guessometer miles still left in the tank...ALL without an interim charge on the road.

I would be very let down, if I could not adjust and obtain the above minimum performance.

I realize that, if her schedule coincides with the coldest days of the year, I may, indeed, be forced to charge while she is receiving treatment. Just thought I would give this real world survival story, with a Bolt.
 

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When I started looking for my first EV about 4 years ago, I checked out the i3 and the local dealer only had one and was not expecting to get any others. Fortunately, it was available to test drive and while I was there the salesman alluded to the fact that the northeast is a terrible locale for EV efficiency so BMW didn't expect to sell many here and sent most down south.
I eventually bought a 2013 used Leaf which went from the all resistant heat to the heat pump in 2013. This and the lizard battery were critical for my search for a 2013 post May production. The heat pump is so much more efficient for 80% of the heating requirements here where the temperatures can get to -10F a few times a year. Anything warmer than about 35, the heat pump would do the heavy lifting.
I'm baffled why Tesla did not see the wisdom in using a heat pump.
 

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As Dyefrog stated - a heat-pump would make for a much more efficient heater. The consensus is that for the Bolt, Chevy was trying to hit a price point and left off that option due to the increased cost. Shame - as you've noticed, heating is a big energy drain as-is. That said, you can save some energy by pre-conditioning (which is great for longer drives - less so for short stop/go driving around the city). Not sure where you are, but I'm up in Ottawa - my dead of winter range is ~ 250km due to heating. Still - for around the city, that is plenty! We can only hope the next platforms all use heat pumps (or have it as an option at least- I would have sprung for it).
 

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As Dyefrog stated - a heat-pump would make for a much more efficient heater. The consensus is that for the Bolt, Chevy was trying to hit a price point and left off that option due to the increased cost. Shame - as you've noticed, heating is a big energy drain as-is. That said, you can save some energy by pre-conditioning (which is great for longer drives - less so for short stop/go driving around the city). Not sure where you are, but I'm up in Ottawa - my dead of winter range is ~ 250km due to heating. Still - for around the city, that is plenty! We can only hope the next platforms all use heat pumps (or have it as an option at least- I would have sprung for it).

I'm pretty sure that HVAC technology type has never been an option choice in any consumer vehicle in at least the last fifty years. I'd be very surprised if it ever was in the future.
 

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As Dyefrog stated - a heat-pump would make for a much more efficient heater.
My experience is that dressing warmly and using the heated seats and steering wheel work quite well most of the way down towards freezing, and below that heat pumps don't work effectively anyway - so it seems to me that their benefits are a bit overblown.
 

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I'm pretty sure that HVAC technology type has never been an option choice in any consumer vehicle in at least the last fifty years. I'd be very surprised if it ever was in the future.
Our '70s (maybe '74?) gold VW 412 had a supplemental gas heater that literally burned gasoline from the gas tank. I think there was a mechanical timer knob (green?) on the dash to run it. Too many years ago, it may have even worked when then engine was off, perhaps lit by a glow plug? Don't remember if it was standard equipment or an option. I think it broke and my dad was not good at fixing anything car. My folks pretty much did nothing more than an oil change and tires till a car rusted away to nothing. Although, I did get a couple of hand-me-down years out of that one my first couple of years in the service. Don't remember why I didn't get it fixed, probably couldn't afford to back then. BTW, it had a "frunk" too, maybe way ahead of its time.

This may the green knob with the instructions, pull, or push to start, or something like that. Found it; it was for "pre-conditioning", how funny is that!

Wow, if you are interested in supplemental heaters, check out this thread!
 

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Our '70s (maybe '74?) gold VW 412 had a supplemental gas heater that literally burned gasoline from the gas tank. I think there was a mechanical timer knob (green?) on the dash to run it. Too many years ago, it may have even worked when then engine was off, perhaps lit by a glow plug? Don't remember if it was standard equipment or an option. I think it broke and my dad was not good at fixing anything car. My folks pretty much did nothing more than an oil change and tires till a car rusted away to nothing. Although, I did get a couple of hand-me-down years out of that one my first couple of years in the service. Don't remember why I didn't get it fixed, probably couldn't afford to back then. BTW, it had a "frunk" too, maybe way ahead of its time.

This may the green knob with the instructions, pull, or push to start, or something like that.

That reminds me of the choke handle on the dash in my 1960 Ford Falcon. Kinda-sorta acted like a cruise control for relatively low speed highways, but it burned gas like a mofo. That was OK with my teen-aged self, until gas hit fifty cents a gallon. The horror!:eek:


It didn't occur to me that I was essentially dumping raw, unburnt fuel into the atmosphere. I was pretty dumb for a smart kid.
 

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I live in the SW USA. I do not believe that I would have chosen a Bolt or ANY EV, if I lived in the extreme north. I actually am totally amazed that many Canadian drivers are happy with and manage the Bolt in that environment.
Here on the southern border of the extreme north, I have not been deterred from staying with an EV. I do wonder how they can be happy with EVs in Canada, and similar cold places, though. I just checked my Bolt now that we've had some winter like weather and Orion used 30% for heat, 0% battery conditioning. My LEAF didn't display this data, but it seems similar to what I guessed the LEAF used. The big increase in capacity over the LEAF and battery conditioning should make the Bolt much more usable in winter though.
 

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The Leaf or Ioniq have heat pumps, which are very efficient when the temp is around freezing or above. Great for them, but they also have small batteries. The battery size in the Bolt is ok for winter travel - we just need the infrastructure to support it. I look at it this way - I want to be comfortable, and driving the Bolt any distance with the climate turned down to, say 65 to 68 degrees with a manually set fan speed (2) is tolerable, and doesn鈥檛 use too much energy beyond the big amount needed to initially warm up car/battery (approx 1 kWh per hour). With this strategy (plus seat heat on low) I can still average over 3 mi/kWh on distant travels (30 miles or more) when the outside temp is just above freezing. The electricity cost to support this usage rate equates to a car getting more than 40 mpg with current gas prices, which is great. The cost of a DCFC when it鈥檚 cold out is at its worst, since the battery takes on power slowly for several minutes, when you鈥檙e charged by the minute, not the kWh. For the rare distant travels, this is the price you pay for driving an EV in the cold, analogous to pulling a boxy trailer with a car that doesn鈥檛 typically tow - how often do you do that? For T Hancock, I鈥檇 value comfort over speed of the trip, but I鈥檓 also aware of the large stretches between cities/towns in NM, so to me it鈥檇 be worth it to occasionally plug in a DCFC for 1/2 hour to make a speedy/comfortable round trip. If one is available to you, I鈥檇 think you should use it if you can, since there can鈥檛 be many users these days. The high energy cost for that one trip will more than be offset by your summer travels. For those of us who drive our Bolts in significant cold weather - each of these days are offset by the car being super efficient on the warm summer days?
 

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My experience is that dressing warmly and using the heated seats and steering wheel work quite well most of the way down towards freezing, and below that heat pumps don't work effectively anyway - so it seems to me that their benefits are a bit overblown.
I agree that heat pumps have significant limitations. They require some sort of supplemental heat to keep one warm in really cold. I did a quick search and see that Tesla does not use a heat pump. But they have patent on what is probably the best cabin heat system for a EV.

https://insideevs.com/tesla-patent-outlines-sensible-approach-cabin-heating/

Edit: I should add that it appears to me that the system approach that Tesla has patented could be adapted in the Bolt easier than adding a heat pump.
 

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Heater energy usage is a constant. The slower you drive, the greater the percentage of your overall energy usage your climate control represents.

That being said, automotive heat exchangers and heat pumps are a band aid. Most are hybrid systems, and while they are more efficient than a resistive heater (like the Bolt EV's), their range of efficient operation is very narrow. Anything under 20 F, and the energy usage between a hybrid heat pump and the Bolt EV's resistive heater will be very similar.
 

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Heater energy usage is a constant. The slower you drive, the greater the percentage of your overall energy usage your climate control represents.

That being said, automotive heat exchangers and heat pumps are a band aid. Most are hybrid systems, and while they are more efficient than a resistive heater (like the Bolt EV's), their range of efficient operation is very narrow. Anything under 20 F, and the energy usage between a hybrid heat pump and the Bolt EV's resistive heater will be very similar.
While true that below 25F, the advantages of the heat pump diminish as the resistive heat takes over but that doesn't negate the benefits between 30F-60F which in most of the US is the sweet spot or at least south of the M-D line.
When your only energy source is electricity, for EV's, the heat pump is a logical choice. It would be ridiculous in an ICEV but benefit/energy use in the sweet spot described above, it's currently the best band-aid, IMO.
Disclaimer, not an ME.
 

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While true that below 25F, the advantages of the heat pump diminish as the resistive heat takes over but that doesn't negate the benefits between 30F-60F which in most of the US is the sweet spot or at least south of the M-D line.
When your only energy source is electricity, for EV's, the heat pump is a logical choice. It would be ridiculous in an ICEV but benefit/energy use in the sweet spot described above, it's currently the best band-aid, IMO.
Disclaimer, not an ME.
That's why I said it's very a narrow window. For me, personally, it's no window at all (I typically only ever run AC and defog).

If the OP was using 25% of their energy for climate control, my guess is that the temperatures were outside the sweet spot for heat pumps anyway. An interesting question to me is how much more would a Bolt EV cost if equipped with a heat pump?
 

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That's why I said it's very a narrow window. For me, personally, it's no window at all (I typically only ever run AC and defog).

If the OP was using 25% of their energy for climate control, my guess is that the temperatures were outside the sweet spot for heat pumps anyway. An interesting question to me is how much more would a Bolt EV cost if equipped with a heat pump?
I've never understood why the existing heat pump that they use for A/C can be reverse cycled for the heat. The probably reason is humidity control where you need both heat and dehumidify so 2 separate systems which I assume is what the Leaf has.
Agree though that it has no value for southern climates and it should be part of a cold weather package.
When I lived in Houston, the heating portion of the HVAC system was a resistance coil only. Didn't make sense for a full blown furnace. Easier to repair too.
 

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The Leaf or Ioniq have heat pumps, which are very efficient when the temp is around freezing or above. Great for them, but they also have small batteries. The battery size in the Bolt is ok for winter travel - we just need the infrastructure to support it. I look at it this way - I want to be comfortable, and driving the Bolt any distance with the climate turned down to, say 65 to 68 degrees with a manually set fan speed (2) is tolerable, and doesn鈥檛 use too much energy beyond the big amount needed to initially warm up car/battery (approx 1 kWh per hour). With this strategy (plus seat heat on low) I can still average over 3 mi/kWh on distant travels (30 miles or more) when the outside temp is just above freezing. The electricity cost to support this usage rate equates to a car getting more than 40 mpg with current gas prices, which is great. The cost of a DCFC when it鈥檚 cold out is at its worst, since the battery takes on power slowly for several minutes, when you鈥檙e charged by the minute, not the kWh. For the rare distant travels, this is the price you pay for driving an EV in the cold, analogous to pulling a boxy trailer with a car that doesn鈥檛 typically tow - how often do you do that? For T Hancock, I鈥檇 value comfort over speed of the trip, but I鈥檓 also aware of the large stretches between cities/towns in NM, so to me it鈥檇 be worth it to occasionally plug in a DCFC for 1/2 hour to make a speedy/comfortable round trip. If one is available to you, I鈥檇 think you should use it if you can, since there can鈥檛 be many users these days. The high energy cost for that one trip will more than be offset by your summer travels. For those of us who drive our Bolts in significant cold weather - each of these days are offset by the car being super efficient on the warm summer days?

The GM EV-1 HVAC used a heat pump...20 years ago.


I was floored that the Bolt used resistive heating. A big step backwards, IMO.
 

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I've never understood why the existing heat pump that they use for A/C can be reverse cycled for the heat. The probably reason is humidity control where you need both heat and dehumidify so 2 separate systems which I assume is what the Leaf has.
Agree though that it has no value for southern climates and it should be part of a cold weather package.
When I lived in Houston, the heating portion of the HVAC system was a resistance coil only. Didn't make sense for a full blown furnace. Easier to repair too.
My understanding (and I'm probably going to butcher what the HVAC system engineer who described it to me said) is that it's not as simple as just reversing the cycle, and it has additional costs including a less efficient AC system (when cooling).
 

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The GM EV-1 HVAC used a heat pump...20 years ago.


I was floored that the Bolt used resistive heating. A big step backwards, IMO.
Was it a heat pump or a heat exchanger? The EV1 used an induction motor, which produces a lot of waste heat which can be scavenged for heating the cabin. A more efficient powertrain like the PMAC in the Bolt EV doesn't produce nearly as much waste heat.
 

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Was it a heat pump or a heat exchanger? The EV1 used an induction motor, which produces a lot of waste heat which can be scavenged for heating the cabin. A more efficient powertrain like the PMAC in the Bolt EV doesn't produce nearly as much waste heat.

Heat pump. You could hear the little compressor running when it was on.
 

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Discussion Starter · #20 ·
I鈥檓 not that concerned about driving around town but I had big plans for a couple of long distance trips this winter.
Will need to better predict range under these new conditions.

I will probably learn the true meaning of DWF.
 
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