Winter Driving Range Extender

I've read several times now of people passing up the I Miev or
others not replacing their lease end I Miev due to having problems with the range, and or comfort level in the winter -
As the heater draws the energy from the battery the range diminishes 30 -40%.

For a commparison.
My understanding is the Volt runs the ice generator motor full time once the temperature reach below -10C to provide cabin heat.

It is a little early at this point but with the experience of adding the diesel liquid heater modification and the early winter temperatures I can say we have not sacrificed our summer driving range so far and enjoy a significant improvement in the comfort level .

The car is a completely different experience in the winter.


There are others who have done this mod before me and I encourage them to pipe in here and share their driving experience.

With limited EV production capacity, this obviously isn't a top priority for Mitsubishi right now. But I hope Nissan (and before too long Mitsu as well) are paying attention to this. An expensive fueled heater modification isn't worth it to me in Albuquerque (where the cabin-warming sun shines right through the cool winter days), but a reasonably priced factory-supplied kerosene or diesel heater option is ESSENTIAL if manufacturers want to sell any quantity of EVs in snow country. We have ample testimony that i-MiEVs and LEAFs go just fine through the snow and ice, so the only thing making them a non-starter for most customers up north is the "range vs. comfort" tradeoff for winter driving. Seat heaters don't cut it for more than occasional use, especially for passengers who might be less committed to energy efficiency.

Customers want warm cabins, and fuel-burning heaters can do the job far more efficiently than draining batteries with power-sucking electric space heaters. Burning fuel to pump air may be a lousy way to move a ton of metal around, but it's fantastic at generating heat. Honda recognized this and offered oil-fired heaters in the late '90s EV Plus trialed in California. Aside from unrealistic and innumerately nonsensical "green" concerns, I cannot fathom why this practical reality is being ignored by current EV makers (a little cabin insulation wouldn't hurt either).

I agree. I think a fuel burning heater would be a popular $1K option if it were offered - I suspect the reason it's not being offered has more to do with legal and liability problems than anything else. They'd rather the end user install it themselves which leaves them out of the picture

I'd LOVE to have one . . . . 5 or 6 times per year. I doubt it would get more than 10 or 20 hours of use each 'winter' down here though. Since range it never a problem for us, the energy wasting electric heater suffices . . . . but, if it had been an option when we bought the car, we'd probably have spent the extra to get it

Don

Well i concur with sandage,

I never really liked the idea that you had to trade winter comfort for range in an ev.

Winter range was my first and biggest concern about buying an ev up here. After two winters of driving and trying all kinds of things to keep warm in the car the diesel heater really makes the cut. It addresses 3 major winter problems:

Window fogup
Driver and passenger comfort
Range

Any solution for heat in the winter that draws from the battery will have problems. I'm not sure how well the heat pump leafs work in the cold weather. I cant see a heat pump making much heat at - 10 deg c. Maybe someone can chime in on that.

The fact that winter range is 40 % less on a nice warm ev is constant for all ev's. Even if you had a 200 mile range car in the winter it would be a 120 mile range car. It would be the same game with bigger numbers. Even the mighty tesla has this same problem. The diesel heater just flattens that all out.

The biggest habitual difference with the diesel heater is that you can blast the heat on high for 15 minutes in a very cold car to bring it up to temp. Typically this is on the drive home after a cold soak during the day with no plug in available. This is something that you tend to not do with the electic heat because it consumes so much to run it on full. You can keep the temp in the cabin much higher if you like. The car is transformed from an always cold car to a always warm one.
The only time you can keep the car just as warm using electric heat is when you have a short trip. Like 30 miles. Then you can blast the electric heat and stay just as warm.

Of course all that frost and fog up completely go away also which is really nice.

I could go on listing positive benefits and presenting some data comparing using the diesel heater vs the electric heat. But its just really obvious. The diesel heat in the car is just like the tons of heat you get in an ice. Its the best mod you can do to the car for this climate. Its true to say it completely changes the driving experience in winter.

That being said i'm sure there are loads of new ev drivers that will discover the winter issues like most of us did and still be very happy with their cars but given the choice I'm sure they would love a fuel heater.

I'm sure this type of thing will make its way into ev's sold in the north. It may just take a little while for it to catch on. If not from the oem then from the after market. Maybe muffler shops will start installing them with the growing amount of spare time they will start to have as ev's take off.

Don.....

I had a couple of Chevrolet S10-E's that had an electric range that was pretty much in line with the I-MiEV. It was designed with A/C but no electric heat at all. Instead, it used a small diesel heater that worked through the standard S10's water heater core (much like the core in the I-MiEV). It had a small fuel tank that was filled through the filler door left over from the standard gasoline truck. It was the first EV that I ever owned that could actually get HOT inside during cold weather (Michigan) driving. Fuel consumption was very low and the small tank only needed to be filled a couple of times during the winter. It's unfortunate that the I=MiEV doesn't use this approach in light of the fact that in the I-MiEV, cabin heat can also be directed into the battery pack if needed. I leased both a 2012 and 2013 LEAF. The former had a electric hot water heater (like the I-MiEV) and took a real hit in cold weather. The 2013 used a heat pump instead of the hot water heater and the change in range during cold weather was not dramatic at all. Pretty much on par with summer A/C usage. I now have a Tesla which uses a combination of heat pump and resistance electric heaters (no hot water) for cabin heat. We have only started with some cold weather but the system really provides a lot of heat. As I am now in Florida, cold is relative and as heat pump effectiveness drops with temperature I can't comment on really cold weather---however heat pumps are a step in the right direction. The coldest I even ran the heat pump equipped LEAF in was the upper 20's and it worked just fine. All that being said, I really think that Mitsubishi should look at heat pumps in lieu of the hot water heater. They have such a good A/C unit in the I-MiEV that it should have the capacity to heat the cabin as well. A couple of reversing valves and software to make the A/C a heat pump would cost far less then the cost of the hot water heater, circulating pump, heater core, piping and high voltage wiring currently installed. Mitsubishi is a world leader in A/C systems--redesigning this should be a cakewalk.

Using the Diesel Heater Today & the Driving Range Results
The Diesel heater ran for 1 hour during the trip. Even while we drove at a pretty good highway speed, we enjoyed fog free windows & a comfortable cabin temperature

Pre Departure Conditions
Parked outside all night 6 bars power @ -18C , 0 Fahrenheit
Timed to fully charge L2 - completed 1 hour before departure & we preheated for a 1/2 hr.

At Departure
Time 7 am
Temperature -18 C, 0 Fahrenheit
Driving conditions Dry roads, no wind or traffic
Topography 244m, 800ft, elevation drop to destination

Country roads
15 km @ 55 kmph - 9.3 miles @ 35 mph

Highway
46km @ 105 kmph - 28.5 miles @ 65 mph

City driving
8.5 km @ 35 kmph - 5.3 miles@ 22 mph

Totla has been edited due to addition error
Total distance 69.5 km, 43.2 miles
Time driving 1:03 hrs

Time of Arrival 8:03 am
Remaining Power 2 bars
Temperature -13C, 8.5 Fahrenheit



Fast Charging Recount
Started immediately at trips end, battery was warmed up from the trip.

Hey Sandy,

After doing a few winter chademo charges i have noticed that the car will limit current to about 50 amps when the lowest cell temp is below a certain temp. I dont know the exact temp limit but at 15 deg c for the lowest cell the charger will run at 125 amps. I did one test witht the lowest cell at 1 deg c and the charger ran at 50 amps.

So the magic number is some where between 15 and 1 deg c. Maybe some others in cold climates could provide some canion data on that one.

So the best scenario for winter driving and quick charging as fast as possible would be to start with a warm battery and keep the temp up by driving fast then quick charging while the battery is warm and then repeating the process to the next quick charger.

You can kind of regulate the battery temp with the speed of driving.

Don.......

It would be good to know what the magic number is for the battery temperature to charge at the faster rate.
Then we can try to limit fast charging at temps colder than that.

@ 40 minutes for 10.7 kw????

Winter fast charging starts to get expensive .55/kwh compare to home .10/kwh
Then add the diesel for heat at those temperatures .5L/1 hour, = $ .60
All together it starts to add up.
The trip down - Total was distance 69.5 km, 43.2 miles

The return trip required a short addition fast charge cost of 3.00
to make up for the hills/elevation climb of 244 meters, 800 feet.

Total trip costs

Home charge ------------1.60
Fast charge 1-------------6.77
Fast charge 2-------------3.00
Diesel fuel ---------------1.20

Total $12.57
Mileage Round trip = 139 km, 86.4 miles