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Location: Moscow, Russia

Practical solutions for extending cold weather range

Wed Feb 08, 2012 2:59 am

Hi Everyone,

We currently ran few MIEVs as test vehicles in Moscow. Now it's around -20C and we have severe range decrease due to that. Maximum we get is 65km in very very ECO and heater almost not used.

The problem is the heater:
- it's all electric "boiler" type which means that it drains about 3.5 kWT of power so it takes about 4 hours to completely deplete the battery without driving
- car insulation (ours are 2011 MY) is insufficient because it simply does not hold the heat, i.e. it takes about 30 min to get to +15C in the car, highest temperature you can get when it's -22C outside is +22C after 4 hours :)

So we are looking for some cost efficient bolt on type of the solution in order to make winter life in I-MIEV less miserable. I'd be very much appreciated for any information sharing on this topic. We are thinking in the way of Webasto type diesel heater to incorporate it into the heating system. Which of course will make the car not zero emission for few month in a year but will definitely make it drivable in climate like ours.

BTW it holds to snow road surprisingly well despite RWD.

Cheers from Russia.

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Re: Practical solutions for extending cold weather range

Wed Feb 08, 2012 10:08 am

I have been thinking of putting my laptop PC in the car turn it on, close the lid, and use it as a heater. :idea: It has its own lithium ion batteries so its still as zero emission as the car is.
John - 2012 Silver i-MiEV SE model, Jan 19th, 2012 w/OpenEvse, caniOn,& OVMS.

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Re: Practical solutions for extending cold weather range

Thu Feb 09, 2012 12:07 am

CHAdeMO, you are in a seriously cold environment! Nice to know that the iMiEV drives well in snow. Quite frankly, the present state-of-the art barely supports operation of an EV in that cold a climate (look at the lower temperature limits in the owners' manual). I'd be inclined to store the car for the winter (in a heated garage) and drive an ICE. A Webasto heater installation would require some imaginative venting and ducting, not to mention that it runs on diesel which sort of defeats the primary reason for an EV. Being in California, I'm clueless as to how to exist in your winter climate, and hope someone has some ideas. (jjlink, even if you filled up the car with laptops you'd still be frozen).
Good luck!
EVs: Two '12 Wht/Blu SE Prem., '13 TeslaMS85, three 156v CorbinSparrowsLi(NMC), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab96
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Re: Practical solutions for extending cold weather range

Thu Feb 09, 2012 5:41 am

I agree that the heater is mediocre, which should've been a slam dunk in an EV, and I haven't completely figured out the remote preheat option. It seems to have a 'sweet spot' of around 15 minutes, and shut down in 30 minutes or so, after which the car cools down very quickly.
When not playing with the preheat, a 1500 watt 'ceramic' forced air heater set on the floorboards will get the car much toastier and 'heat soak' the interior before departure, which I've found really takes the load off during my 30 minute commute.
2012 i-SE "MR BEAN" 126,300 miles
2016 KIA SOUL EV, 90 kW, 27 kWh, 34k miles
2000 Mazda Miata EV, 78 kW, 17 kWh
1983 Grumman Kurbwatt EV,170 kW, 32 kWh
1983 Mazda RX-7 EV 43 kW 10 kWh
1971 "Karmann Eclectric" EV 240 kW 19 kWh

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Re: cold weather range. The heat is the Great Equalizer

Thu Feb 09, 2012 1:44 pm

CHAdeMO wrote:...The problem is the heater... drains about 3.5 kWT of power...

The heater is the great MPH equalizer:
Doubling the speed from say 30 to 60 MPH might half the Range from 6 miles/bar to 3 miles/bar, but that would half the heater energy for the same range.

If the heater is using 3.5 kW while the car is at 35 mph, which is about 5.5 kw and 6 miles/kWh, the car is using 9 kWh. 35miles/9kWh= 3.9 miles/kWh
If the car is at 50 mph, which is about 9 kw and 4.6 miles/kWh, the car + heater is using 12.5 kWh. 50 miles/12.5 kWh= 4 miles/kWh

If the heater is being used for the entire trip we could go 50 mph instead of 35 mph and use the same amount of energy.

If the car is at 60mph, which is about 15.3 kw and 3.9 miles/kWh, the car + heater is using 18.8 kWh. 60 miles/18.8 kWh= 3.2 miles/kWh

Do you have a way to preheat the battery? Derating the range by 1% per °C below 25°C gives a 45% reduction in range.

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Re: Practical solutions for extending cold weather range

Fri Feb 10, 2012 10:06 am

Ok we suppose to have a technical meeting to work out best solution next week with local importer of Mitsubishi Motors. They say there is no standard solution recommended by the vendor however they are offering several option which we will discuss looking at the car together with their service guys.

Stocking EV in winter is not our way. We are crazy Russians and we will be driving all winter 'round all of our EVs ;)

BTW I-MIEV is leading subcompact segment in terms of sales in numbers in Norway! :) Of course due to 0% registration tax which is 120% otherwise but still over there it's even colder than we have got.

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Re: Practical solutions for extending cold weather range

Tue Apr 17, 2012 12:03 pm

I can't imagine using an EV with current technology in that kind of environment...but I wish you well.

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Re: Practical solutions for extending cold weather range

Tue Apr 17, 2012 2:28 pm

Cold weather use is an issue here in northern New Mexico. Our winter nights routinely get down to 0F (-18C), and daytime winter highs are usually around 35F (+2C). We have a garage that we heat to 50F (+10C) in the winter, and are hoping that allows for a more complete charge. We can also pre-heat the car. I'm hoping that going from 50F to 65F inside the car can be accomplished in a few minutes of pre-heating.

CHAdeMO: have you tried garaging your cars in the winter? If so, does that make a difference?
2012 iMiEV
2007 Zenn
1998 Honda EV+
1995 GM Impact prototype consumer test driver
... over 60,000 miles in electrics

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Re: Practical solutions for extending cold weather range

Tue Apr 17, 2012 4:51 pm

First, I preheat while it's plugged in and use the seat heater. Then I tried this "NanoSafeguard" stuff that I found on the web to help with defrosting. Sounds like a gimmick but it helps keep he windows defogged. So far it has worked very good in Seattle's mild wheather. I usually drop one bar commuting 6 miles to work. This morning I didn't preheat so I used the heater intermittently and used two bars getting work.
I tell everyone that you can be cold and drive far, or be warm and drive short. The seat heater uses the auxiliary battery!

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Re: Practical solutions for extending cold weather range

Tue Apr 17, 2012 6:36 pm

Our winter's in New Zealand are not as cold with about -4 being the usual where I live. As our 2012 model year NZ specification car does not have the remote start or preheat option found in the USA 2012 models, we had to come up with a solution for the iMiEV for Winter motoring as we park the car outside in the drive even in Winter as the garage is full already.

The solution we came up with is a small electric fan heater with thermal cut out switch, which will turn off the heater if it gets too hot, and a thermostat on the heater that cycles the heater on and off to keep a desired temperture.

This means the car can be on a seperate power circuit from the heater, and so use the ful circuit load for the car charging if need be, and the heater has it's own 10 amp 230 volt 50 Hz circuit for heating.

The car at our tempertures should reach a nice 22 degrees C from - 4 degrees C in about 15 minutes.

The important points are :

Very much ensure the heater is not pointed at a place which would get too hot and catch fire, and ensure nothing will fall onto the heater such as jackets or coats or the homework paper.!.

For extra safety, we turn the heater to low output so the heater takes longer to get the car to temperture, but is not so hot that it is so important to be extra careful about the direction of heat flow.

Put a timer on it so that it resets after 30 mins so the heater isn't on unattended for very long.

The top of the dash but facing into the car should work well on low, though a heatproof silocine rubber mat underneath the fan heater is a good idea for heat and vibration protection for the dash.

Not as cool or easy as a remote start or timer heater built in, but should work if that option is not on your car. :idea:

That solves the preheat option, but the car soon cools off when driving, so insulation is a must, the door panels have a bit of space behind them and the floor pan underneath the car can be fitted with a sheet of insulation with plastic wrapping for water and humidity sealing, insulation like fiberglass batts or similar. Wrapped Sleeping bag insulation works too.

The Roof panel can be insulated too, but would be fiddley to do. The boot panel and side pockets would also benefit from this and would keep the car a bit cooler on hot days too.

I covered the iMIEV's radiator grill to protect the radiator against stone chips while road testing when I didn't have the aircon on, and this might help reduce heat loss from the cold outside air hitting the firewall but it would be best to check that doesn't affect the battery cooling when working the motor hard or while charging.

But yes, I think the diesel heater like that used on boats or Campervans woud be also good, but might be hard to vent , perhaps placed under the front hood ?.

Another thought..You know how the heated seats help for warmth, and using the same idea, what about 12 volt electric blankets on the roof panel or behind it, it would give off a heat similar feeling to an overhead sun maybe.

The 12 volt battery can be supplemented with an additional one in the boot perhaps or the front one could be replaced with a larger one. Any 12 volt usage is charged from the iMiEV main battery so without an extra battery, the 12 volt usage would be lowering the main battery too, and for every 12 volt 100 amp hour battery added, you get the equivalent of 1,200 watts though at say less than 50 % discharge, that would be only 500 watts, but that is enough for a 120 watt electric blanket on full for 4 hours !

Also we are thinking of putting a 140 watt solar panel, the flat flexible type, on the car for topping up the 12 volt back up battery, so we can leave a radio on while working or to cool the car on fan only while having a break on the side of the road.

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