Bolt winter performance, an ICE comparison

[SeanNelson]

People might want to think about wearing a heated motorcycle vest / jacket, and use 75-100 watts (at most) rather than firing up the 3,000-5,000 watt cabin heater.

Neil, I think this is the kind of post that Leftie is referring to. We justify cheap workarounds on a $40,000 car to solve issues when an automaker could have simply designed it right in the first place.

To be fair, even the most efficient heat pump is going to use a lot more power than direct heat appliances like a vest or blanket. Trying to get warm by heating the air (and therefore all the rest of the car's interior surfaces too) is terribly inefficient no matter what you use to heat the air.

No matter how large the battery pack there's always going to at least some people who have marginal range and for whom these kinds of issues matter. But the good news is that the larger the battery pack, the fewer people fall into that category and so the Bolt's winter range, even with it's inefficient heater, will be problematic for fewer people than 30 to 40kWh cars even if they do have a heat pump.

Yeah, it would be nice if the Bolt had a heat pump. But it would be also nice if it had Adaptive Cruise Control, a hard button on the dash to activate the cameras, a lighted charge port, etc. etc. etc. It is what it is, much like Popeye.

 

[oilerlord]

To be fair, even the most efficient heat pump is going to use a lot more power than direct heat appliances like a vest or blanket. Trying to get warm by heating the air (and therefore all the rest of the car's interior surfaces too) is terribly inefficient no matter what you use to heat the air.

You're missing the point, Sean. Joe Public won't be buying a heating or cooling vest to save on kWh's to make up for the car's inefficiencies. It doesn't matter if heating cabin air is "terribly inefficient". When normal people are cold, they tend to turn on the heat...they don't typically shop around for "solutions" that should have been designed into the car.

EV's are popular in Norway too, not just California. The point is that GM (and others) shouldn't just assume that a resistive heater is "good enough" for everyone. We're not talking about fluff like a lighted charging port or a button to activate the rear camera. If simple & relatively cheap technology exists that allows the car to be more efficient in colder climates - then it should be in the car.

 

[LeftieBiker]

Hey, unlit charging ports are a real PITA in full darkness! ;-) I do agree that a heatpump should be an option, if only because the car is so damned expensive now. Nissan is doing that with the "new" Leaf: charging something like $1100 for the heatpump and seat and wheel heaters in the SV. People in California will benefit, but for the rest of us that's an automatic increase in the base price.

 

[oilerlord]

Yeah, I shouldn't have called it "fluff". No doubt there are various features that are very big deals to some, and for valid reasons. I just think more EV's should have heat pumps, or at least an option for those that will make use of it. I wish my EV had one.

 

[LeftieBiker]

For me it's the steering wheel heater. I have Reynaud's disease because of bad circulation, and unheated steering wheels feel like they are made of dry ice in Winter - even with gloves on.

 

[globecanvas]

172/238 = 28% drop from average in cold weather
!

That is about what we have seen, also upstate NY. My wife commutes to Albany once a week which is 140 miles r/t, and last week she made the trip on a full battery with about 30 miles of range left.

The real test will be this week, as it will be around zero degrees -- hopefully the range drop-off isn't linear with temperature!

 

[LeftieBiker]

You can mitigate range loss due to heater use in several ways. The best way is to use recirculation as much as possible, to stop the heater from having to continuously heat frigid air. Most cars don't allow recirculation in Defrost mode, but some will allow it with floor/defrost modes. (The Leaf has a 'secret partial recirculate mode', in which you get 30% fresh air and 70% recirculated air.) Running the fan at the lowest effective speed also helps. People who are alone in the car can also close the passenger side heater vents. Use the seat and steering wheel heaters to help reduce the need for cabin heat. I have also used a 12 volt heated fleece blanket over my lap and legs, to reduce the need for cabin heat. It was actually nice and cozy. I'm not one of those 'no heat' EV drivers, though - I always run the heat unless I really fear not making it to my destination.

 

[SeanNelson]

People who are alone in the car can also close the passenger side heater vents.

Can you do that in the Bolt? I haven't figured out how to do anything other than point them over to my side of the car...

 

[LeftieBiker]

People who are alone in the car can also close the passenger side heater vents.

Can you do that in the Bolt? I haven't figured out how to do anything other than point them over to my side of the car...

I don't know - I just assumed yes, as most cars allow that. If not, then GM strikes again...

 

[BikingManiac]

In the cold midwinter of northern Wisconsin, my power use increased so that I was at 2.2 miles per KWH today over 65 miles. Briefly at 1.8 miles with 28% going to battery conditioning. Temp was -10 F rising to -2. Charging from near empty to 88% SOC is still about 50 KWH, so a comfortable range is just over 100 miles. I can’t wait for Spring and those 280 mile charges again!

 

[winterescape]

In the cold midwinter of northern Wisconsin, my power use increased so that I was at 2.2 miles per KWH today over 65 miles. Briefly at 1.8 miles with 28% going to battery conditioning. Temp was -10 F rising to -2. Charging from near empty to 88% SOC is still about 50 KWH, so a comfortable range is just over 100 miles. I can’t wait for Spring and those 280 mile charges again!

WOW! stay warm and keep us posted...

 

[globecanvas]

We have been getting about 2.0 m/kwh in upstate NY during the past week of temperatures around 5F. Total range at this temperature is about 120 miles, which is not enough for my wife to make her weekly commute to Albany without stopping to charge.

In the summer we were frequently getting close to 5.0 m/kwh for 300 miles of total range.

 

[SeanNelson]

We have been getting about 2.0 m/kwh in upstate NY during the past week of temperatures around 5F. Total range at this temperature is about 120 miles, which is not enough for my wife to make her weekly commute to Albany without stopping to charge.

Have you checked your energy information screen to see what percentage of your energy consumption is due to cabin heating? I've found that heat is by far the biggest reason for the cold weather range reduction. Now I know that 5F is pretty darn cold, but if you can reduce the heater requirement a bit you might find that she has enough range for her commute. It could be as simple as wearing a warmer jacket, boots and hat, or it could be something like a 12V heated blanket which is much more efficient at applying heat directly where it's needed instead of trying to warm the entire cabin. I understand that there are even heated socks available!

And don't forget preconditioning - you waste the most heat on that initial warm-up of the cabin, so if you can do that while the car is still plugged in it will leave substantially more juice in the battery for the trip.

 

[Williams60]

Its been down around -28 Celsius (-18F) most nights for the last month or so here, with the daytime high being a max of -15C (5F). At these temps you need the cabin heater as well as the steering wheel/seat heaters otherwise you get ice on the inside of the glass from your breath freezing; its worse if you've showered before going to work!!

The range is doing much better than I expected; the worst I've seen is 210km range with a full charge, which allows me to still use the hilltop setting which gives me around 190km range (which is less than 50% of my summer range, where I was regularly getting over 420kms......). Just for interest, the actual range I've got has always been pretty close to the cars' range prediction when charged. The range prediction tends to drop pretty steeply in the first 30% of use (which is always causes unnecessary concern....), but then recover as I run toward the low end of the battery's capacity.

 

[oilerlord]

Observations:
1) The Bolt DTE “distance to empty” being prominently displayed makes the driver keenly aware of the reduced distance in the winter, contrast this to the ICE where just the gas level is displayed, so the driver has no idea that the distance to empty has dropped off by 20%. No one monitors the DTE screen on an ICE vehicle, no one.

2) With the lack of significant waste heat, the battery characteristics, and resistive cabin heating, the Bolt DTE falls off by a larger % than an ICE vehicle in the cold weather, but not by an unreasonable amount.

Conclusion: Stay warm this winter, enjoy your Bolt, and think Spring!

Umm....pretty much every ICE vehicle on the market these days has a DTE screen or readout. People driving ICEV's don't typically mention them and/or thier level of accuracy probably because those readouts are irrelevant. 600 miles of range, and 5-minute fill-up isn't thought of as an amazing technological breakthrough on a fuel efficient car. It's just expected, regardless of the season, or ambient temperature. No thermal underwear, heated socks, or 12V electric blankets required.

In terms of a winter (range) performance comparison, I have never experienced 30-50% range loss in winter with any other vehicle I've ever owned; but it happens frequently with my EV. Unfortunately, that sort of extreme is normal for a lot of us. We may try to sell ourselves on the notion that it isn't an "unreasonable amount" - but really, we aren't fooling anyone in the ICEV community; only ourselves. It is unreasonable. We just accept it.

 

[GetOffYourGas]

In cold weather, a BEV has to use propulsion energy for heat whereas an ICEV has waste heat the rest of the year which it can now use to heat the cabin for "free".

In cold weather, batteries simply hold less energy than when they are warm. So you have less energy to start with.

These two (large) factors are unique to EVs.

Yes, Physics can be just so gosh darn unreasonable.

IMO, it's not a matter of us having "accepted" the loss in range, it is simply inevitable. There are lots of things we can do about them, though. Many EVs have the option to preheat the cabin based on a departure timer (why doesn't GM offer this?!?). Our Bolts do have a TMS to keep the battery somewhat warmer, although it is implemented so as to prevent damage and not to increase range. Charging to full right before a long trip also warms the battery. Tesla recently added the ability to heat the battery for increased driving range, I think GM should do the same.

 

[oilerlord]

IMO, it's not a matter of us having "accepted" the loss in range, it is simply inevitable. There are lots of things we can do about them, though.

Brian, you can spin it however you want. Early on in the Bolt launch, Michael and I were advising others on this board to expect range loss of up to 50% in winter, but most didn't believe it - and why would they? That extent of extreme range loss has never been a factor in driving an ICEV. The fact is, the onslaught of "what's happening with my range" posts as winter approached was an absolute certainty. We'll continue to go through the laundry list of "reasonable" solutions like preserving range by choosing to freeze, or using electric blankets instead of turning on the heat. It will happen again next winter, and the next winter after that. That is also simply inevitable.

 

[GetOffYourGas]

I'm not trying to spin anything and I agree with you. My issue is when someone states or implies that it is "unreasonable" that an EV would get so much less range in the cold. That's simply the wrong way to look at it. It is in fact very reasonable. The problem is, as you point out, that it is completely unexpected to the uninitiated.

Back in 2012 when I bought a Leaf, Nissan made me read and sign a document that, among other things, listed range in a variety of conditions. It specifically stated the car was expected to get 35 miles of range in sub-zero temperatures with the heat running. That's on a car which said "73 miles" on the sticker. Chevy did not make me sign any such document. As the market picks up, educating new consumers will be very important. In 20 years from now, EVs may be so commonplace that it's no longer necessary but in the meantime, we'll continue to have an onslaught of "my battery is dying!" posts every time it gets cold.

 

[winterescape]

Observations:
1) The Bolt DTE “distance to empty” being prominently displayed makes the driver keenly aware of the reduced distance in the winter, contrast this to the ICE where just the gas level is displayed, so the driver has no idea that the distance to empty has dropped off by 20%. No one monitors the DTE screen on an ICE vehicle, no one.

2) With the lack of significant waste heat, the battery characteristics, and resistive cabin heating, the Bolt DTE falls off by a larger % than an ICE vehicle in the cold weather, but not by an unreasonable amount.

Conclusion: Stay warm this winter, enjoy your Bolt, and think Spring!

Umm....pretty much every ICE vehicle on the market these days has a DTE screen or readout.


....We may try to sell ourselves on the notion that it isn't an "unreasonable amount" - but really, we aren't fooling anyone in the ICEV community; only ourselves. It is unreasonable. We just accept it.

Of course they do, see the section I bolded above

For you it may well be unreasonable, for me compared to my expectations and the performance of my ICE vehicle, I feel it is not unreasonable. I am not Justifying anything to myself or others, just expressing my opinion. Feel free to disagree...

 

[IMAdolt]

I just finished up with an extended test drive and when I first got the car due to timing I was only at about 60% charge with a GOM range of about 160km. So not great, it was funny because the salesman was more surprised then I was that the range estimate was so terrible, that works out to a total range of about 270km full charge. The previous test driver had the heater cranked to something like 30 Celsius and I'm assuming every other heated device on in the car, the pie chart showed something like 27% power usage for climate and 2% for conditioning.

After driving the thing for around 2.5 days keeping the cabin temp to 18/19c (not uncomfortable for me) and using heated seats/wheel as required I got the climate usage down to 20% and a estimated full charge range of around 320km, pretty big difference, and in reality I was averaging a real time usage of like 80% of that, about 80km used for every 100km I actually drove, I managed to put over 300km on the car so I had a decent run in it.

This part of BC isn't the coldest place in the world but at the time we were getting temps from around 0 to -10c, I guess my point is that simple habits make a difference? As for the snow/ice performance I found it superior to any similar sized FWD ICE car I've ever driven, it had all seasons on it, exact brand I cant remember.