Cold Weather Range

I wouldn't mind it if the battery warmer and cabin heater were powered by a small propane or alcohol cylinder tucked away in the trunk, rather than from the traction battery to help optimize cold-weather range.

 

I drove from Albany NY to Elmira NY for Thanksgiving, a little over 200 miles one way, and had an interesting experience. On the trip to Elmira conditions were rough in many ways. Temp right around freezing with precipitation almost the whole trip changing from misty rain to light snow and wet roads the whole way. Very, very strong headwinds, cloudy, and a significant increase in elevation - 700 feet. I drove at 68 mph with the heater at 68 degrees on driver only and with the seat heater at either the middle or low level. I stopped and charged at Country Club Nissan in Oneonta (about 80 miles from Albany) and added about 20%/40 miles. Good thing I did. I was close to empty when I arrived at my destination. So I used almost all the 120% of my battery to go about 210 miles. The car reported that I got 2.9 miles/Kwh, but I think it was less. I got to the house I was going to with 8 miles of range. Luckily the hotel I was staying at was just 3 miles away.

I spent the night at a Fairfield inn and charged overnight. On the return trip conditions were much better. Temperature was about the same but it was dry with no wind and I was traveling downhill. I again stopped at Oneonta and added about 20%. When I got home, I had the full 20% left, so I used 100% of my battery for about 200 miles. I used the same heat/seat-heater settings. The car reported that I got 3.1 miles/Kwh on the return trip.

I guess the point of all this is that when the temps drop really low, I'll plan on getting much less than 200 miles on a charge. The second point is always add more charge/range than you think you'll need.

 

That's probably fair. For our own trip we started at 90% charge, but we had a 20mph headwind the whole way. Route was flat - total of about 70 miles. We got there with 50% charge. My wife was driving, and insisted on going 75mph, which didn't help either. Temps were in the 40s.

On the way back we no longer had the headwind, of course - we had a slight tailwind if anything. We would have gotten home with about 30 miles on the GOM.

Having the heat on always makes a significant dent in the range - there is no way around that one. The heated seats help part of the way, but our feet get cold with the heat off, so we turn it on with the heat directed down on our feet. The heat can be weird sometimes - when we first turn it on, it doesn't seem like we get much warm air, but give it a minute or two and it starts to blow warm air. That seems a little counter-intuitive - since it is electric, there isn't a reason I can think of why you wouldn't get warm air right from the start. There was one time it was actually blowing uncomfortably warm air - I think we had the temperature setpoint set up to high at that time.

We did stop at a DCFC, not so much because we needed to, but so that my wife could learn how to use the thing. And I kind of like to check them out from time to time mainly to make sure that they are working properly and to gain confidence that in a pinch I can really depend on them (and to show a little support). So we only stayed there 15 minutes or so and continued on.

 

I’ve similarly found that keeping the cabin heater at 68f, I’m getting about 2.9-3.1 mi/kWh in the cold. Normally, I only charge to 90% at home but if I know I have a long day of driving ahead, I’m bumping it to 100% just to have the extra margin.

 

I have a thermometer plugged into the 12v socket, and it takes a very long time to get warm down there, even with the footwell flow. Relying on Auto set to 21C, it seems like half an hour before suddenly you realize your front side is warm and the temperature in the bin has risen from 0C to 15C or so. I haven't tested the non-eco climate setting to see if it works faster.

 

With the Nissan Leaf the regen cuts out the moment any wheel slip is detected.