Nissan Leaf Range update

i think the scenarios provided are varied enough to get an idea of what to expect. heat will always use less power than AC but then again the weather conditions will be the determining factor. will a lot of Diff bet John1701A in Minnesota and htmlspnnr in AZ. both will see a significant reduction.

also, in any conversion of energy, heat is a by-product. it would be foolish to not incorporate that into climate control. that is probably why AC is more of a drain. another thing to realize is that we, by design are able to withstand much more cold than heat. (at least some of us...my SO is an exception!!). i drive a Zenn with a very weak heater, i rarely use it even in winter. right now, its near winter temps about half the time. we are still waiting for the official "end of cold" here (temp that hits 75º F) we set records daily for longest streak. previous record was June 9th and the extended forcast says the record will continue.

also, after looking at the range estimates. i have to say that it does not appear that 24 KWH is usable. its back to 90% of that. EV efficiency has been reported as high as 6 MPW. and as low as 3 on an NEV. if we look at the extremes. 138 miles in near perfect conditions that would be about 6 miles if 21.6 KWH is available. on the worst end its just over 2 miles per KWH.

now all the scenarios are easy to imagine except the worst one. in any stop and go situation, time and distance can be a huge variance. its easy to believe that u could get 45 miles on a charge if its a 90 min crosstown commute in rush hour traffic. this is the same situation people reporting 33 mpg in a Prius experience.

 

How efficient the heater or AC is depends completely on how it's "made".

If the heater is basically a big resistor, then it will be lacking in efficiency. A heat-pump will "make" heat up to 3x more efficiently than a resistance heating. A heat-pump is basically an AC system that is able to run backwards as well as forwards.

In the end, as you allude to, how much energy it takes to cool/heat the interior depends completely on environmental conditions and the desired interior temperature. Physics wise, if the temperature differential between inside/outside is 20* higher/lower than the desired temperature, a heat-pump will require the same amount of energy to either heat/cool the car.

That does ignore the effects of direct sun radiation, however, which significantly increases the amount of cooling capacity needed when it's hot out.

 

which is the overriding factor.

a 20º difference for heating or cooling a car is not the same and radiant heat is the reason why.

full sun with mild temps often require A/C. if its cool enough like here (pacific NW) then the vent will do. this is a reason why my mileage is good without my doing much as far as hypermiling. i simply drive conservatively and with temps in the 60's, a vent works fine. but if temps are as low as the low 70's; well within the comfort range, the temps inside a car will still be very uncomfortable and a vent wont cut it.

in my Zenn, i rarely use heat because if temps are in the mid 40's in winter, many times radiant heat is enough to keep in comfortable.

 

Eek. You must like it cold.

If it's below 60* here I normally blast the heater for a good 15 minutes. I don't crank the AC until it's over 75* or the car has been baking in the sun with the windows closed.

Anyway, in the Prius with a set it and forget it automatic climate control system I rarely move the temperature setting more than a couple degrees from 73*F. Not sure how much AC actually gets used in those conditions, but I suspect it's very minor.

If the Leaf had a solar roof option like on the Prius I would think that would go a long ways towards extending range for when you have to park in the sun with the windows closed.

 

In the old days, when it was hot, we opened the windows. Believe it or not, there was a time when cars didn't have A/C. My Xebra does not have A/C. But the windows crank open, and I get a nice breeze.

 

a few think i eskimo blood in me, but if its 50º with good sun, i am plenty warm. sometimes i wear a sweater or a light jacket, but usually not. now that is 20º below the "comfort zone" of 70º. when its 90º there is only so many clothes i can take off and if i could get away with taking them all off, i would still need something.

i guess i spent too much time in the midwest or Alaska where it was freezing in the car for the first 15 minutes of every trip we took. it didnt bother me a whole lot back then (i actually drove a VW bug that seemed to NEVER get warm in Michigan winters and i did mind that VERY MUCH but it was better than walking)

 

Found something interesting. From EPA Fuel Economy Data spreadsheet, it specified that Leaf's battery pack is rated 360 Volts and 66 Ah. That comes out to 23.76 kWh.

Volt's pack is rated 348 Volts and 45 Ah making it 15.66 kWh. If we round them up, Volt has 16 kWh and Leaf has 24 kWh battery capacity as max.

 

that is capacity but usable is still just 21 kwh. more or less

 

I have been caught in traffic jams with my Prius, and I wouldn't want to be caught in a jam without some sort of backup. I believe the Leaf has no ICE backup?

 

no ICE backup. but what does a traffic jam have to do with burning gas while idling?

The Leaf could sit for hours and use very little power. even if running A/C that would burn a Kwh/hour more or less. i guess if the traffic jam lasts for more than a day, it might be an issue, but better hope your gas tank is full as well

 

no ICE backup. but what does a traffic jam have to do with burning gas while idling?

The Leaf could sit for hours and use very little power. even if running A/C that would burn a Kwh/hour more or less. i guess if the traffic jam lasts for more than a day, it might be an issue, but better hope your gas tank is full as well

FYI; last Saturday it was hot and we just couldnt keep cool even with trips to the pool. so we jumped into the Leaf and basically drove around for 3 hours. we only started with about a 70% charge (range in eco mode was like 75 miles) drove around, ate fast food very slowly in the car. (after the pool were not really dressed for public so never got out of the car)

then took a trip past a few new construction sites. one of which being a building for the Providence Medical Group which SO is employed. also drove by the site of the new Childrens Hands On Museam, etc.

had A/C on the whole time. swung by Dairy Queen grabbed ice cream then went home. only cruised city streets. only put on about 40 miles on the Leaf, but got home, still had like 20 miles of range left.

 

If it had ICE backup it would not be an EV. The Volt has battery plus ICE. It's the worst of both worlds: All the maintenance overhead of a gas car, all the issues of battery uncertainty; the dead weight of the ICE when driving electric and the dead weight of the battery when running the ICE, burns 50% more gas than a Prius when on road trips, and only seats 4 rather than 5. Its poor gas mileage makes it really only good as a commuter car, but with less than half the range of a Leaf, the Volt is a poor choice even as a commuter car.

What you are really saying is that you don't want an EV because of its limited range. That's a big issue for some folks. I drove a 40-mile EV for 4 years (until I bought the Tesla just a couple of months ago) and I never had any problems regarding range. I just drove the Prius if I was going to have to drive farther than about 30 miles. IOW, I always left myself a buffer for unforeseen traffic situations. Even that's not an issue for me any more because I'm never going to drive even half the range of my Tesla unless I'm on a road trip, and then I'd need the Prius anyway for its cargo space.

Running out of juice in a traffic jam if you've planned your driving within the range of your car is probably less likely than having a breakdown in a conventional car. What do you do when that happens? You call a tow truck. Some people are just so used to gas cars that they are afraid of something better. But of course if you prefer to burn gas, by all means do so. I prefer to "burn" electrons, but that's just me. Gasoline stinks and we get it from people who fund terrorism. My electrons are American made.

 

Dave - have you ever used the consumption screen? Here's mine running on the coldest morning we had driven in, last March (35 degrees). You can see the heater is consuming over 3kWh at that moment.



I've read of others seeing the consumption meter as high as 4kWh on sub zero days. Of course that's why the Gen II will have heated seats - so you don't waste juice heating the air - just you! .... a 4Kwh drain could empty your e-tank in only 5hrs just sitting still without traveling, if you hadn't pre-warmed during charging. As you mentioned ... during AC, the consumption gauge will show you're only consuming about 1.5kWh.

 

heat definitely uses a lot more but you said it. it would take 5 hours to run out the pack on a very cold day. i hope to never be stuck in traffic that long and all cars have the potential to run out of fuel of any kind while stuck in traffic much longer than expected. look at all the people fleeing a hurricane from Houston a few years back. pretty much everyone but Priuses and people lucky enough to have a full tank ran out idling away in the heat.

i am not saying it wont happen. trust me, it will. we have people here nearly every week reporting running out of gas in their 500 mile range Priuses

 

Not to be picky (OK, I'm being picky) but the h is redundant.

 

Yes, that annoys me also. Rate of consumption is measured in kilowatts, NOT kilowatt-hours. Even the picture shows "kW," not "kWh."

 

Not to be picky, but your current consumption is always measured in kW. It will only be equal to the same number of kWh if you use the same amount of energy for an hour.

Your actual consumption over an hour (kWh) will seldom be an equal number to your current load, since it will normally change. i.e. put your foot on the accelerator to scoot forward in a.traffic jam will change your load and your actual kWh for the period.

 

The key phrase though is "at that moment." Unless you have the heater set excessively high, it will cycle off once it reaches that temperature.

I had a couple of 32 degree mornings and with pre-heating from shore power and my HVAC set at 65 degrees, it only went up to 3 kW for about 5 minutes and then settled down to 1.5-2 kW for the rest of my 65 minute commute.

Overall though, Dave is correct, you can be stuck in traffic for quite a while and not lose a significant amount of charge. I like traffic now though because it lowers my average speed, improving economy!

 

I agree with this.. Is what I do regardless of what the temp is outside. About the only time I roll up the windows and use climate control is when it is raining outside. To be honest running the AC affects the mileage in my Volt, but not to some drastic degree.. Cannot speak for the Leaf, but I would think Nissan's system would have a similar power draw. A lot of these people are also driving EV's like they would a sports car trying to prove that the cars cannot work. People will need to change their driving habits, but in the end I think that will be a good thing. Tired of people riding my bumper or zooming around me when I am already doing 5mph over the speed limit to begin with.

 

temps play a huge part. now that we are starting to get high 50's to low 60's my performance in town has gone from 5.6-6 miles/Kw to 4.7 to 5 miles per Kw and that is NO climate controls. so temperature alone has affected my performance more than the occasional use of A/C which really changed my performance in most cases by only .1=.2 miles/Kw.

now, as it gets colder, heat will be needed and i will be at 3.5-4 miles/Kw