Practical solutions for extending cold weather range

[Kuuuurija]

A quote from the article above (sorry for my rapid and poor translation):

One of the first electric car users in Orava county, Rein Kraak, made a statement, that the car is able to drive at -29.5 degrees Celsius up to 76 km and has no problems with starting in frosty conditions.

In fact, he made only a 4 kilometer trip, and the range was estimated only according to the cars guess-o-meter, which showed remaining range at the beginning of the journey as 80 km and as 76 km at the end. There is no information on whether the car heater was turned on or not and so on. But a positive image was created: "The electric car drives well at the minus 30 degrees C".

A day later, the same person told in national broadcasting, that his car could drive about 80 km at -28 degrees. And there's no concern about starting a car in the frost! Just toes will freeze, as you drive!

At the same time, however, newspaper Tartu Postimees wrote that two electric cars had to be towed to the Mitsubishi retailer to warm up the batteries! It turned out that the cars have batteries without heating, and if they are not constantly hanging from the wire, then after quite a short standing in the frost, they will not start anymore. Which information is correct?

Whatcar.ee editorial seeked for answers from a familiar social officer, who testified that he did not believe in claims of the car user from the Orava county: "Cold affects the range very much. When there are warmer days, a fully-charged battery can run up to 70 km , then down to minus 20 degrees in just 40 to 50 km", said the social worker, who drives his iMiev mostly in the city. On the road it would take more energy and mileage probably would be even more scarce.

"I think at cold temperatures, however, the worst problem is that the power steering stops working, " said social worker, who was still not completely certain whether this was an universal problem, or just his cars specific trouble .

But getting the car warm is a completely separate issue. "It warms up still very slow. Such luxury like you start a car and then sliding the warmers slider up to the end (like in regular car), would mean that the warming would half empty the batteries. Just today I finished an experiment: I started the heater in the standing car and let it go. The battery was 80% full at the beginning, but after an hour, it was completely empty. "

There are also problem with charging, because social workers have usually no opportunity to park the car into the warm and safe garage. On the courtyard, there are fears that costly five meter charging cable can be stolen, if left over night unattended. Also, no one asked him to keep a journal about how many kilometers at which temperatures can drive , etc. .

 

[Don]

It turned out that the cars have batteries without heating, and if they are not constantly hanging from the wire, then after quite a short standing in the frost, they will not start anymore. Which information is correct?

iMiEV's which came with the cold weather package do have a battery warmer, but as you say, it needs to be plugged in for this to function. I don't know if I would choose any EV if I lived where you regularly have -30C temps and I did not have a garage to keep it in

If the car 'will not start' I would expect it's more likely a problem with the 12 volt auxiliary battery, as that's what gets it up and running. I cannot imagine that the 330 volt lithium traction battery would not move the car because it's too cold, but if the 'car would not start' indeed it wouldn't move either

 

[jaraczs]

The roof and windows have a lot of heat escaping, but the doors look cool.

How about EnerLogic window film? Checkout the video:
http://www.enerlogicfilm.com/en/HowDoesItWork.aspx

It has the ability to reflect heat away in Summer and reflect it back in Winter. It is particularly effective for single pane windows.
Stan

 

[Kuuuurija]

Is there any other experiences with power steering not functioning in frosty condition?

 

[JoeS]

If you're looking for a simple way to add heat and extend the car's range in the winter and you want to do it electrically, why not keep it simple . . . . really simple?
Buy 40 of the Headway 38120S 10 amp screw tab LiFePo4 cells (about $17.50 each) connect them in series for a 128 volt auxiliary battery pack (1.28KW) and then use them to run a standard household ceramic 10 amp 120 volt heater? If you replaced the fan motor in the heater with a DC motor, you wouldn't even need an inverter. Attach a voltmeter to monitor the pack and shut off the heater when the voltage drops to 90V (2.25 volts per cell) so you don't harm your battery pack

Don, funny you should have mentioned this, as that is exactly what I have but more powerful: two 4P8S Headway (LiFePO4) packs made up of 12Ah cells. Total capacity is 64*12Ah*3.33v =~2.5kWh. I use this 48V (nominal) system to power my electric outboard or 48v electric bicycle or my 48v-->120vac 2500W inverter or 24v electric scooter. I load-tested this system using... wait for it ... an electric heater! Worked like a charm. To greatly reduce cost, a couple of 12v Group 31 (~100Ah) batteries and a 1000W 12v-->120vac inverter and a 600W ceramic heater should be good enough for most commutes in the iMiEV, and certainly cost less and be less-complicated than a Webasto or Eberspächer (Espar) heater.

Besides, isn't there something immoral about consuming fossil fuels in an electric car? :mrgreen:

I heated my 10m catamaran using a 600W electric heater in each hull when cruising southeast Alaska and was toasty. Even with all the conductive and radiated losses of our almost un-insulated iMiEV, I would expect a 600W heater sitting on the passenger's side aimed at the footwell to at least keep toes from turning blue ... but, being in California, what do I know about seriously-cold weather? :roll:

Off-topic and maybe a candidate for a new thread: when I used my Headway packs to run the 48v-->120vac inverter, it charged the iMiEV just fine for the ~10 minutes I tried it. When I tried the same thing using a 48v-->240vac 2500W inverter feeding the EVSEUpgraded EVSE set to 6A, the $200 eBay inverter blew up! Hmm, as I write this, I have to wonder if I remembered to reprogram the EVSE to 6A? :roll:

 

[MLucas]

It turned out that the cars have batteries without heating, and if they are not constantly hanging from the wire, then after quite a short standing in the frost, they will not start anymore. Which information is correct?

iMiEV's which came with the cold weather package do have a battery warmer, but as you say, it needs to be plugged in for this to function. I don't know if I would choose any EV if I lived where you regularly have -30C temps and I did not have a garage to keep it in

If the car 'will not start' I would expect it's more likely a problem with the 12 volt auxiliary battery, as that's what gets it up and running. I cannot imagine that the 330 volt lithium traction battery would not move the car because it's too cold, but if the 'car would not start' indeed it wouldn't move either

A few of us developed a Cold Weather Chart last winter. The i-MiEV will not charge or start below -30c/-22F. The Battery Warmer only operates between -15c/-30c.

http://myimiev.com/forum/viewtopic.php?f=28&t=713

 

[Kuuuurija]

Thank you, MLucas! I missed the thread completely! This scheme is very helpful!

 

[Kuuuurija]

How many times one has to charge his/her Leaf to drive 2x185 km (from Tallinn to Tartu and back) at -10...-15 degrees Celsius? See the video: http://www.tv3play.ee/play/301364/
It takes 12 hours of charging and driving (average speed is ~30 km/h), and there are some distances, where the cabin heating has to be turned off to reach the next charger! An average range per charging is below 80 km, and yes, this is Leaf, not iMiev!
What about the cost? 8 chargings discharge from your pocket 40 €. This makes 10.81 € per 100 km.
For 40 € you can buy 30 litres of gasoline here.

 

[jray3]

So since Mitsu is not using the stock battery heater for pack capacity optimization, only 'freeze protection' (it doesn't come on until 5 degrees F!), there has been interest in a supplemental pack heater.
Stick-on heat pads designed for RV water tanks may be an option. They're available in a number of different sizes, power levels, and temperature settings (such as on at 40F, off at 65F).
http://www.dyersonline.com/rv-plumbing/rv-holding-tanks/holding-tank-accessories.html?cat=69
Some can even be switched between 120 VAC and 12VDC, though it would be hard to justify pulling amps from the battery to heat the battery!

It ain't cheap, but could make a difference in colder climes, with less risk of unintended consequences from messing with the in-car circuits! It also appears that there is room to add insulation to the smooth tray that sits under the battery (which is very noisy on a gravel road), and there may be clearance to place the heat pads between the battery and bottom tray.

 

[NeilBlanchard]

If you use the heater and/or the defroster, then your range will be less than in warm weather. Sometimes a lot less using both the heater and the defroster can use as much energy as moving the car.

 

[jray3]

If you use the heater and/or the defroster, then your range will be less than in warm weather. Sometimes a lot less using both the heater and the defroster can use as much energy as moving the car.

It's not just the increased load of cold weather operation. Like all batteries, lithium loses capacity in the cold, approaching 20% at 0 degrees Celsius. Here's a nice chart.

http://www.google.com/imgres?imgurl=http://blog2.optibike.com/wp-content/uploads/2009/12/lithium-battery-temperature-vs-capacity.jpg&imgrefurl=http://blog2.optibike.com/2009/12/10/lithium-battery-performance-in-cold-temperatures/lithium-battery-temperature-vs-capacity/&h=362&w=509&sz=62&tbnid=vy-4t02V1jSdOM:&tbnh=90&tbnw=127&zoom=1&usg=__lWHyxfahe_vPe_ioc4nkO6RKJjw=&docid=1i8bB8IDXztREM&sa=X&ei=y29lUrurI-K3iwK5p4GADA&ved=0CFcQ9QEwBA

Keeping the pack warm will retain that capacity, regardless of whether you increase load by running the heater or defroster.

 

[tonymil]

This study looks at both, the effect of ambient temp and the use of the heater-a/c.

http://www.nrel.gov/docs/fy13osti/58145.pdf

 

[jray3]

This study looks at both, the effect of ambient temp and the use of the heater-a/c.

http://www.nrel.gov/docs/fy13osti/58145.pdf

Thx- interesting takeaway is that the higher resistance encountered in cold-weather charging makes more amps go straight into heat than if the battery started out warm. So, there's another reason that cold charging takes longer- some of our charger output is just making heat internal to the cells, but it's sort of a positive feedback loop that will temper the effect of cold weather. I prefer to end a charge right as I begin a trip rather than hours before anyway, since the less time spent at high SOC, the better.

 

[NeilBlanchard]

The battery is warmed up by charging it - and it warms as you using it, so, the ambient temperature is not the same as battery temperature. Also, the cold weather package has a battery heater included, so warming the battery will happen one way or another.

The heater and the defroster are by far the largest reasons that winter range is lower than summer range.

 

[jray3]

But Neil, the OEM battery heater doesn't come on until negative 15C/5F, while the battery is happiest around 25C/77F.
In the NREL paper, it says that the battery lost over 50% of capacity at -20C. Imagine cutting our rated range to 31 miles, and then turn on the heater and watch RR drop to 21 miles or less.
If the battery was kept near 'room temperature' we wouldn't be adding load to a weakened battery. Folks using Canion this winter should be able to add a lot of clarity here.

 

[michaelev]

Heating pads: I agree it would be a chore to get them (and the insulation) installed but I've put them in other car applications before and it worked well. Pb Batts lose about 50% of their capacity in cold conditions so it was well worth the effort there:
http://the-redmenace.blogspot.com/2009/03/hot-batts.html
Michael

 

[MLucas]

Instead of heating pads or other extreme measures to keep your battery pack warm, why not try charging the car before you need it? I've been following this practice since last year and have always had good results. I'm usually seeing only 1 or 2 extra bars used during winter mostly because of heater use. This year I have my MiEV-CAN working and can actually see the battery temperature, giving me proof that my charging method is keeping the batteries warm. This morning on the way to work I took this picture showing the outside temp at 4c/39F and my battery pack at 18c/64F. I have not started to put the car in the garage yet as I still need to clear out the summer items, once I do that I should see better results. This was the first time this season I heard and saw the low outside temp indicator. It's starting to get cold up here.

 

[fjpod]

good advice.

 

[RobertC]

From the Mitsubishi Canada website.
http://www.mitsubishi-motors.ca/en/i-miev/faq/

How far can I travel with the i-MiEV?
The i-MiEV can travel up to 155km at a single charge, based on EPA LA4 city mode.

Actual range varies with driving behavior, charging habits, use of air conditioning and heater, weather conditions, road conditions, use of regenerative braking system, drive mode etc. The following are some sample of driving conditions that you may encounter in real world driving.

* The figures are a range estimation to be expected in each driving condition with a new condition battery. MMSCAN cannot guarantee the range to be achieved. Actual range will vary depending upon driving/charging habits, speed, conditions, weather, temperature and battery age.

Ideal driving conditions:
Approx. 160 km(100 miles)
Speed: Average 60 km/h (38 mph)
Temperature: 25ºC
Climate control: Off

City driving on a nice day:
Approx. 120 km(75 miles)*
Speed: Average 24 km/h (15 mph)
Temperature: 25ºC
Climate control: Off

Highway driving in the summer:
Approx. 104 km(65 miles)
Speed: Average 80 km/h (50 mph)
Temperature: 35ºC
Climate control: COOL On

Local commute on a hot day:
Approx. 80 km(50 miles)
Speed: Average 24 km/h (15 mph)
Temperature: 35ºC
Climate control: MAX COOL On

Winter, traffic jam:
Approx. 48 km(30miles)
Speed: Average 16 km/h (10 mph)
Temperature: 0ºC
Climate control: HEATER On

Sounds about right to me.
You can go 100 miles at 38mph with no climate control.
You can go 50 to 65 miles with the air conditioning running.
You can only go 30 miles if you are stuck in a winter traffic jam (unless you turn the heat off!).

They don't have any scenarios that show the loss in range from going 70mph.

 

[RobbW]

If you use the heater and/or the defroster, then your range will be less than in warm weather. Sometimes a lot less using both the heater and the defroster can use as much energy as moving the car.

When you say "defroster", are you referring to the "Defrost" setting on the climate control or the rear-window defroster? I also have a question about the climate control defroster setting specifically. I usually keep my setting on the Feet/Defrost position to help keep the windows clear and my footsies from freezing. However, I notice that when I change from the feet/defrost position to only the defrost position, my RR immediately drops an additional 5 miles. Is there something different about using the defrost-only position that would eat up more of my range?

Now that it is getting colder where I live, I have been noticing a decline in RR every morning when I unplug and head to work. When I bought my Meepster in July and for the rest of the summer, I was normally seeing an RR between 75-80 miles first thing in the morning after charging overnight. Now, with overnight and morning temps in the 30s and low 40s, my average starting RR is around 65 miles. And this is with my i-MiEV being garaged. With the climate control in the feet/defrost position, the fan on auto, and the heat set to two clicks above the green dot, my RR will usually drop from the mid-60s to the low 50s immediately. Still plenty for my 30-mile round trip commute and a little errand running. However, I'm starting to get concerns about my effective range in the dead of winter. One of these days, I plan to do a live run-through of worst-case scenario to see how my i-MiEV performs. I plan to drive my entire round-trip commute with the heat fully blasted just to see what my effective range is so that I can plan for the dead of winter accordingly.