My winter driving range has dropped a lot!

[nikalex]

My Guess-o-meter usually only shows between 80 and 85 kms RR these days (50 - 53 miles RR) first thing in the morning after a full 16 bar charge. My drive is 60% highway and 40% secondary 40mph roads.
It has been cold here lately (at least cold by Vancouver standards ) at below zero °C (-5°C to -10°C which is 23°F - 14°F)- sorry in advance to those folks in the real cold!
This RR is cutting it way too close for my commute.
I am preheating the car in the Morning using my remote while it is still plugged in. But I am also using the heater and heated seats during the commute.

To make matters worse when I did an odometer check my odometer and speedometer is reading 3 - 4% high using my original OEM size Dunlop tires.
I assume this is also penalizing me in terms of actual range.

Is anyone else seeing a drop in range like this?

My I-MiEV is a 2014 SE edition and I am running winter tires as well.
Bridgestone Blizzak WS60 tires. My rear tires are a little tiny bit smaller than OEM, fronts are identical.

I can not plug in at my place of work.
I could ask some neighbouring businesses though.

Cheers,
Roman

 

[Don]

I would bet that driving in snow with snow tires is costing you a good bit of range . . . . but, if I use the heater much, my RR will drop from it's normal reading of 75 miles or so to around 50, so no doubt the heater is responsible for a good bit of your loss

If you intend to keep the car long term and it's your principal vehicle, a diesel heater upgrade would probably be a wise move

Don

 

[nikalex]

Thanks a lot for this info.
Makes me feel a bit better that there is nothing really wrong with my little I-MiEV.

The only thing wrong is that I like the heat on in the winter!

My summer range is much better - about 50% more than my winter range roughly. I go from an average of 80kms RR to about 120kms RR.

Still not stellar but much better.

I love the I-MiEV and wouldn't trade it. Have to make it work. Don't know much about the little diesel heaters. Must be similar to what I had in our previous sailboat. It had an Espar diesel heater with exhaust coming out through the deck.

 

[fjpod]

I can only give you my own personal estimates based on my 2012 imiev that I have owned for 4 years or so.

In cold weather, I lose at least 10% of range. No snow, no heat, no snow tires,... just the same driving. The batteries just lose range, which comes back in the spring.

If I use the heat or defroster, the loss is much greater. At least another 25%, and sometimes more if I get stuck in traffic.

 

[magicnote]

I have noticed a huge drop in range in the cold weather as well. We are just coming off a cold spell in Seattle, and the battery was barely making it though the day when I had the heat going. In the summer months, we rarely went below 75% charge at the end of the day for our typical routine. So that's a pretty big change during cold weather - and this was the coldest weather that our i-Miev has ever experienced. Our car is 5 years old now, so there might be some battery degradation as well. It may be time to upgrade to a car with a bigger battery. I wish there was an upgraded i-Miev in the works.

 

[Don]

If you have no summer range problems, then maybe you will want to look into a better way to heat the car, rather than upgrading to a significantly more expensive car? A diesel heater install might solve all your winter problems

Don

 

[jray3]

I have noticed a huge drop in range in the cold weather as well.

Hi Magicnote, it looks like you're realizing about a 25% range loss with use of the heater. As another Seattleite, I'd say that's right on the money. If you have the heated driver's seat, that can offset a lot of heater use, and all it takes is lukewarm or even air-conditioned flow across the windshield to keep it fog-free. Heating these cars electrically is a great luxury with the remote (pre-departure), but keeping one nice n toasty while driving is a recipe for 40 miles of practical range.

 

[blackheart]

I wish there was an upgraded i-Miev in the works.

I bought my 2012 as a 4 year old lease return with 1170 miles on it. I was banking on someone making a replacement battery pack for it someday ;-)

I have been using a 12v blanket to keep the heater use to a minimum. I got it for $7 on clearance. It doesn't get really hot (like the seat seams to at times) but it does well enough to take the edge off - especially since we have had one of the coldest winters here in a long time.
I did have to break out the 4x4 Dino-monster for about a week due to the snow and ice we had. Today tho, it was a balmy 34°F on my drive in and I decided to not use my blanket. Pre-heated the care on the 120v plug (never gets really warm using that plug - I should have used my 220v...). Sure enough, I kept the heat on and saw my RR going down.
Normally, when I get to work when it has been colder like this, I would have between 42 and 45 miles left on the meter. Today was 36. I am tossing that up to 1) cold weather, 2) insufficient pre-heat before unplugging, and 3) not using my 12v blanket and using my heater more.

Still, plenty of range to get home - but no real wiggle room. My commute home is mostly uphill so my power use on my commute is more like 35% going to work and 65% going home.
Long term - I am going to be looking into the diesel heater - but short term, try the 12v blanket - it helps - ALOT!!

 

[PV1]

The cold itself doesn't have any major affects on range until you get below 10 F, causing a noticeable drop. But below 0 F is when range really starts to fall off, even without heat (45-50 miles max). Running the heat will easily take another 10 miles off of that. The heated seat alone makes quite a difference, as do insulated driving gloves.

It's been rather easy to make the comparison this winter, as temperatures would dive into single digits for 3 days at a time, then rocket up to the mid-50s F on day 4 :roll: . I bailed on January 8 and took the C-Max to Pittsburgh instead due to the cold, but rode the eBike this weekend when it was 65 F.

I agree with others, if winter range is tight due to heating, a fuel heater would be a major game changer.

 

[magicnote]

Don, I'm hoping the upgrade isn't that expensive. We seem to be on the cusp of 200 mile range EVs that are quite affordable. The Tesla Model 3 looks like a fantastic car for the money if Elon Musk can keep it to the price that he promised. We have had a great experience with our i-Miev and will keep it around as a workhorse. Ours has always had two car seats in the back that are a pain to get in and out, so I never really got to take advantage of the hauling space with the seats folded down. If our new car becomes the family car, then we can finally take advantage of all the cargo space in the i-Miev.

jray3, I haven't been tracking the range closely, but it feels like more than a 25% drop. But we also have to run the heat a lot more than most since we have two young kids in the back seat. That heated driver's seat is all I use when it's just me in the car, but it won't do anything for them in the back.

blackheart, I like the idea of the heated blanket, but we would need at least three blankets going when my wife and kids are in the car.

I'm also not sure how much an external heater would help with our situation. We would only be able to use it in the morning and the car is kept in a garage overnight. The garage isn't heated, but it's mostly below-grade and the entrance is shielded from the wind. I wasn't checking the morning temperature that closely, but I don't think it went below 50 even on the cold days. The big drain for us is heating the car after it has been sitting outside in a parking lot or on the street.

Thanks for all the suggestions!

 

[veimi]

Just for fun, I made a spreadsheet to give me an idea of range reduction when using the heater

The results are only an estimate, but interesting nonetheless.

First the assumptions

1. The range of the car at 30mph with a fully charged battery is 60 miles

2. The range of the car at 60mph with a fully charged battery is 25% less or 45 miles.

3. The heater at full heat draws about 5,000 Watts which means that the car sitting in your driveway with the heater at 100% will discharge the battery in about 3 hours.

The results:

1. A trip at 30 mph with no heater - range 60 miles
Car - 16KWH
Heater 0 KWH

2. A trip at 60 mph with no heater - range 45 miles
Car - 16 KWH
Heater 0 KWH

3. A trip at 30 mph with 50% heater - range 45.5 miles
Car - 12.2 KWH
Heater 3.8 KWH

4. A trip at 60 mph with 50% heater - range 40.5 miles
Car - 14.4 KWH
Heater 1.6 KWH

5. A trip at 30 mph with 100% heater - range 37 miles
Car - 9.9 KWH
Heater 6.1 KWH

6. A trip at 60 mph with 100% heater - range 36.5 miles
Car - 12.98 KWH
Heater 3.02 KWH

I think it's correct. I thought others may find it to be of interest.

 

[Don]

3. The heater at full heat draws about 5,000 Watts which means that the car sitting in your driveway with the heater at 100% will discharge the battery in about 3 hours

The heater will never draw 5Kw continuously, even when set to 100% - The heating element cycles on and off. In my case, when set to 100% it's actually on for less than 50% of the time. The cycle time would probably vary depending on how cold it is, but even below zero I'm sure it would still cycle on and off

It's really hard to come up with hypothetical numbers that are close to what you'll get in actual usage - There are just too many variables

Don

 

[veimi]

The heater will never draw 5Kw continuously, even when set to 100% - The heating element cycles on and off. In my case, when set to 100% it's actually on for less than 50% of the time. The cycle time would probably vary depending on how cold it is, but even below zero I'm sure it would still cycle on and off

It's really hard to come up with hypothetical numbers that are close to what you'll get in actual usage - There are just too many variables

Don

Thanks for the real life information.

Based on this I have modified the data below to effect a 50% duty cycle on the heater element.

First the assumptions

1. The range of the car at 30mph with a fully charged battery is 60 miles

2. The range of the car at 60mph with a fully charged battery is 25% less or 45 miles.

3. The heater element is about 5,000 Watts, but the real life duty cycle at full heat is likely 50% or less which would suggest that with the car sitting in your driveway with the heater fully on, the battery would discharge in about 7 hours.

The results:

1. A trip at 30 mph with no heater - range 60 miles
Car - 16KWH
Heater 0 KWH

2. A trip at 60 mph with no heater - range 45 miles
Car - 16 KWH
Heater 0 KWH

3. A trip at 30 mph with 50% heater - range 52 miles
Car - 13.8 KWH
Heater 2.2 KWH

4. A trip at 60 mph with 50% heater - range 42.5 miles
Car - 15.1 KWH
Heater 0.9 KWH

5. A trip at 30 mph with 100% heater - range 45.6 miles
Car - 12.2 KWH
Heater 3.8 KWH

6. A trip at 60 mph with 100% heater - range 40.3 miles
Car - 14.3 KWH
Heater 1.7 KWH

 

[JoeS]

veimi, nice analysis. Don't forget, the range of our i-MiEV is whatever it needs to be to get us to the destination, as we force our driving style and speed and heater settings to make it happen.

Simplistically and more on-topic, the i-MiEV RR display drops by around 20% when the heater is activated, independently of its 'heat' setting.

Intuitively and looking at your numbers I'd be wary of going 40 miles at 60 mph with the heater on (but, then, I always like a safety cushion) :roll: By the same token, with no heater at 30 mph I bet I could get over 100 miles.
http://myimiev.com/forum/viewtopic.php?f=28&t=208&start=40#p17565

 

[blackheart]

veimi, nice analysis. Don't forget, the range of our i-MiEV is whatever it needs to be to get us to the destination, as we force our driving style and speed and heater settings to make it happen.

When I speak to people about this, I get the most interesting questions - and it turns people off from electric cars in a big way. This winter, my little car has become very, very basic transportation - to work and back. There just isn't enough battery left if I use any heat at all.
That is a HUGE turn off for people. I remind them that I have gone over 10k, and NEVER went to a gas station, never waited in line, never smelled like gas - oh, also, never changed oil, or oil filter, or air filter, spark plugs, wires, cap, rotor -etc. All on a car that cost me $8k. And then remind them that I NEVER will.
But we are spoiled and accustomed. I remind them that their ICE car is soooooo wasteful in making excessive energy that they have to purposefully cool it down or it will melt itself down and destroy itself. They heat the cabin from this wasted energy - and it is wasted whether they need it or not.
One of my friends tried to firm up his stance saying that it was just excess. I said 'do you use it'? He said only when it is cold. I said 'can you shut if off (making excess energy)'? He said no..... THAT my friend is waste. Don't tell me how 'efficient' your ICE car is if it is making so much excessive energy that without containment it will melt down.....

This will be an easier hurdle to overcome with cars coming that have the 200 mile range. Adoption of the electric car has always been about range - but heat is the hidden secret of the electric car that stymies people from converting. That should be soon coming to an end.

**So, I think I need to develop some great, easy to install kits for all of the seats in our mievs to be heated. And magicnote - it would be relatively easy to add some more 12V plugs around the car. Some other folks on this forum have probably done it. My wife sits on the blanket when we drive around, so it is like a heated seat for her, but there are kits to install heating elements in other seats as well. I think that will be my 'warmer' months project on my little car.

I am excited about the 200 mile cars. I know that my next car/truck will not be an ICE and will have more miles than my little miev. But I still love my little car!!

 

[Don]

I agree that cabin heating is probably the single biggest 'problem' with owning *any* EV . . . . even one with a 200 mile range. You get used to what you have and if you can make a 200 mile trip in the summer, but only have 150 miles in the winter because you have electric heat, that's *still* going to be a problem for many folks. Most people are used to being very comfortable in their cars when there's ice on the hood and we just don't have that. We even have problems keeping the windows clear

Direct electric heating just isn't a very efficient use of energy, even to heat a house - Oh, we have groundwater heat pumps which do a good job of keeping your house comfortable and they can get you up there on par with other heat sources, but directly using electricity to warm a heating element isn't the way to go - Anyone else ever live in a house with 'baseboard radiant heating' who wasn't dismayed when they got their power bill? . . . . and a big part of that was even spending all that money every winter, the house still wasn't very comfortable

If a DIY owner can install an efficient diesel heater smaller than a shoebox in an EV for $750 or so, it stands to reason the factory could do it for much less. For no more cost and no more room than it takes, It should at least be a factory option on all EV's IMO, or better yet, make them standard equipment which would bring the cost down even more. Then the large cold weather range drop (and the fogged up windows) would no longer be seen as the big negative it is today. I live where it doesn't get that cold and use of the OEM heater doesn't restrict my travels hardly at all, but I still miss the toasty warm cars I've had in the past - If I had a diesel heater, I'd use it . . . . maybe only for a month or two, but it would still be nice

But, when you have a car which runs it's whole life without needing to go near a gas station, I guess it can be a bit hard to admit that there are still a few things that burning fuel does better

Don

 

[Lic]

Heat pump would be enough for me. AC doesn't bother me in summer, so think it will be the same with heat pump.

 

[sandange]

Veimi
Nicely done . Thanks for sharing.

I think this is a great reality Range tool for any one considering to own an i Miev.

I find the stats pretty Clear & accurate & compare to my findings.
I assume you're tests were done on fairly flat terrain.

I've noted that there is a significant energy savings between traveling
50 mph & 60 mph, (80 kmph & 100 kmph)
Wish you had done a similar test at 50 mph ( 80 kmph)

Here is a copy of the info sheet I offer to people we give at test ride events with the AVEQ group in our region.

 

[Don]

Heat pump would be enough for me. AC doesn't bother me in summer, so think it will be the same with heat pump.

The A/C does a great job, but it's also a much simpler job. When it's 95 degrees outside and you want it to be 70 degrees inside, it is only dealing with a 25 degree differential, but when it's 30 outside and you want it to be 75 inside, you're dealing with a 45 degree differential . . . . and on a 30 degree day, I think you'd probably prefer 80 or even 85 inside

A heat pump would use less energy for the heat produced, but an air to air heat pump really loses efficiency as the temps fall below 40 or so. They would still use a similar amount of energy when it's 30 outside and still not give you ICE like comfort when it's cold out without also giving you a significant drop in range - Much worse than you have when using the A/C

Don

 

[Lic]

I know heat pump pluses and minuses and I am still think it will be enough for me. I don't want to say I don't need heater, but we already almost have heat pump so it will be good if for electric cars manufactures will start making AC with ability to work like heat pump too. As I know tesla has heat pump, now leaf too, so may be mitsu will start one day.