Venturing out in the cold in my Leaf!

[venk25]

I've to make a trip tonight:

- total about 55 mi RT
- approx travel time = 1:15 hrs
- ~36 mi will be on highway, rest on 30-40 MPH roads. ~55-60 mph on the highway
- Outside temperature will be a frigid 10F
- Not much elevation changes.

I'll charge to 100% & pre-heat before leaving (Level 2 EVSE). No option to plug-in at destination.

This is 2nd time I'll be be doing this trip. I had ~10 mi in GoM at the end of first trip. The difference now is
- its colder by 30 degrees now at ~10F => batt will hold less charge
- I'll have to use climate control more because its damn cold outside. I used CC sporadically in my first trip since it was warmer at ~40F then (ha! 40F and am saying "warmer" ) and since that was my first 50+ mi trip & I wanted to be safe.

You think I can make it?

In these 10 days I've had my Leaf, though my traction motor usage and regen are decent, the climate control kills my energy economy (because of cold weather) - I average 3 mi/kWh or a tad less per CarWings (ranges from 2.7 if I use CC more to 3.4 if I use it 50-60% while driving).

A question I have is does my 3 mi/Kwh from CarWings factor-in CC usage or not? I reset dash meter often, and last I recall, it was 2.9 mi/kWh.

If CarWings data didn't factor in CC usage, then I need to factor that.

If my total energy usage is 3 mi/kWh, is my math right that I can do 57.6 miles? :|

24kWh batt. 80% usable range = 19.2 kWh. @ 3 m/kWh = 57.6 mi.

Besides, do I need to further reduce for lower temprature per TonyWilliams's chart?f=31&t=4295? If so, it'll be 15% less (70F-10F=60F/4=15%). 57.6 less 15% = 49 miles

Or if I just use TonyWilliams's chart to calculate (ignoring my energy consumption from dash/CarWings),

55 MPH -> 85 mi. Less CC usage 2.5 bars (@ 1 bar/hr @ 1.5kWh. I may avg 3kWh tonight) -> ~68 mi. Less temp adj 15% -> 57.8 mi.

By CarWinger energy use -> 57.6 mi
By TonyWilliams's chart -> 57.8 mi

Does this mean CarWings data factors in CC usage & temperature??

If I'd need to charge to reach home, there are a couple ChargePoint charging stations near my destination and on my way back home. I can stop at one of them and charge for sometime. I haven't used any public ones till now. They are supposed to be free per ChargePoint.com map. But I don't have a CargePoint RFID card. Per my understanding, I can call ChargePoint to activate the stations without a card, right? Otherwise, I may be in trouble!

 

[jswilson]

I just did 70 kms on a 100 per cent charge, at -20 degrees Celsius, all in eco mode, avg speed about 70 km/h, and made it home with low battery warning. Climate control was on automatic all the time, set at 21 degrees Celsius. Lesson: ambient temps and climate control have a huge impact!

 

[venk25]

Conversions for the lazy like me

70 km = 43.5 mi
-20 degrees Celsius = -4 degrees Fahrenheit
21 degrees Celsius = 69.8 degrees Fahrenheit

Looks like if I don't take it easy on CC, I'd have to charge or I'll be in trouble!

 

[TonyWilliams]

A question I have is does my 3 mi/Kwh from CarWings factor-in CC usage or not? I reset dash meter often, and last I recall, it was 2.9 mi/kWh.

If CarWings data didn't factor in CC usage, then I need to factor that.

If my total energy usage is 3 mi/kWh, is my math right that I can do 57.6 miles? :|

24kWh batt. 80% usable range = 19.2 kWh. @ 3 m/kWh = 57.6 mi....

By CarWinger energy use -> 57.6 mi
By TonyWilliams's chart -> 57.8 mi

Does this mean CarWings data factors in CC usage & temperature??

You've done a good job in factoring this, with a few errors. Before I touch on that, though, you already know the answer... It's going to be close, whether you come up short or not!!!!

The battery is 21kWh usable when new at 70F or greater, not 24kWh.

So:

3 miles/kWh * 21 = 63 miles range autonomy (new battery at 70F or greater)

3 miles/kWh * (80% * 21) = 50.4 miles range autonomy (new battery at -10F degrees)

Good luck, and dress warm for the hike!!! Or, slow way down, no heater and you might make it. You've got to get the economy above 3.

Oh, yes, the economy includes heater use.

 

[Computerizer]

I drive 25 miles each day, and when it's in the upper 20s to lower 30s outside, with CC on Auto at 66 degrees and using the heated seat and steering wheel, on roads going mostly 55 mph and 40 mph, in ECO, I use almost exactly 50% of my usable charge. Thus my max range under these conditions would be 50 miles. Since your condition is even colder, I don't see you making it 55 miles, though if you pre-heat for an hour or so to start off with you might get better results (I usually forget to do that).

Personally, if it's this risky, I'd plan on stopping at the first charger on the way home (or the last on the way there) for an hour or so to add the extra miles you might need. I don't like to risk being stranded, especially when it's that cold out!

I've never used ChargePoint myself, but I know that AeroVironment has no problem with you calling them to turn the charger on. I would assume ChargePoint is similar.

 

[philipscoggins]

Maybe when you leave to go back home you drive to the nearest L2 & charge for a bit. That way you can also heat up your car while on shore power while you wait for enough bars to appear for the long drive home.

When I bought my car, I drove away at 9:00pm at 30deg for an 85 mile drive home. That was my worst range anxiety trip, because although I'd researched how to drive the LEAF & had an extended test drive, driving it when it's really cold for a distance takes getting used to. BTW, I did have two QC stations on my path home, which I stopped at, but still it was nerve wracking especially with 2 kids in the back seat (booster seats, so seat heaters don't help)

Philip

 

[MrIanB]

Try leaving an hour earlier than you were planning, pick up something to eat/snack, stop at a L2 or QC charger on way for an hour and then proceed to your destination. I think this will ensure you make it back.

Good luck and let us know the outcome.

Ian B
78 degrees sunny Cedar Park, Texas

 

[mwalsh]

I just did 70 kms on a 100 per cent charge, at -20 degrees Celsius, all in eco mode, avg speed about 70 km/h, and made it home with low battery warning. Climate control was on automatic all the time, set at 21 degrees Celsius. Lesson: ambient temps and climate control have a huge impact!

As they would say on 'Top Gear'...what is that in Church of England? :lol:

Though I see that venk25 has already converted for us.

 

[ksnogas2112]

Did effectively same trip yesterday over the course of the whole day so I lost some charge with the car sitting around and it was about 30 avg for the day (4 bat temp bars whole time). Got home with low battery warning so the 4 mile difference because of battery temp makes it tight but doable. I was using heater in the morning when it was 10*F to keep the windows clear with 3 people in car.

Hope you made it. Let us know.

 

[Reddy]

Don't know if this will help, but while you are charging before leaving, you could "heat" the battery by placing several 100 W bulbs (can you still get those :shock: ) under the car. On really cold days we used to hang a light under the hood to keep the ICE/battery just a "touch" warmer. It helped starting up.
Reddy

 

[garsh]

I do this trip every day, and it's been about that cold here the last few days.

I have a 60 mile round trip in hilly western PA. I do 55mph on the highway, and I leave the climate control off (I'll turn on defrost for a minute when the windows start to fog up). I wear a heavy jacket, hat, & gloves. I use the steering wheel & seat heaters. I keep a (full-size) spare tire/wheel in the back, and I have snow tires, so that's been eating into my range a bit. But I make it.

Just take it as easy as possible on the accelerator, and I think you'll be fine.

 

[mkjayakumar]

Isn't it interesting to note to the lengths we go, to do a trip on a Leaf when the same trip can be done so easily on the ICEv sitting in the garage, not one but two of them ?

For instance this whole week I have been doing 70 mile round trip commute on my Leaf with a 10% degraded battery, and that has made the typical 45 minute one way trip on an ICEv (all on freeway) to over an hour+ in the Leaf driving through backroads and slowing down considerably. That is over 30+ extra minutes of driving, just so that I can make the Leaf do the job.

Does it bother me? No. In fact I am looking forward to tomorrow's commute.

 

[EdmondLeaf]

Isn't it interesting to note to the lengths we go, to do a trip on a Leaf when the same trip can be done so easily on the ICEv sitting in the garage, not one but two of them ?

For instance this whole week I have been doing 70 mile round trip commute on my Leaf with a 10% degraded battery, and that has made the typical 45 minute one way trip on an ICEv (all on freeway) to over an hour+ in the Leaf driving through backroads and slowing down considerably. That is over 30+ extra minutes of driving, just so that I can make the Leaf do the job.

Does it bother me? No. In fact I am looking forward to tomorrow's commute.

The big question is: what is more important your adventuring nature to show that is possible or gallons of gas that are not used for that trip, or both?

 

[venk25]

Thanks all! I made it back home safe!

Summary:
- distance covered: 50.4 mi (skipped a stop I was planning; took care of it in ICE car before trip). ~35 mi on highway.
- 4 miles flashing (LBW) in GoM when I pulled into garage.
- LBW came up about 1.5 mi from home
- didn't charge during the trip
- ECO mode throughout; a few "N" Neutral costings.

- pre-heated for 20 mins before leaving
- GoM showed 90 mi in ECO mode when I started the trip. It was 15F outside.
- didn't use CC for the first 18 mi
- turned on CC at 18.5 mi, set at 68F, A/C off, recirculate. It dropped my GoM range by 8 mi from 60 to 52
- cruise control set at 55 mph entire time on highway
- 3.8 mi/kWh in dash when I reached my destination
- 14F at the destination
- GoM read 45 mi when I parked. 7 battery bars left

- was parked outdoors for approx 2 hours.
- Lost 1 mi in GoM and 1 bar while parked (probably was right in the border when I parked)
- CC was on throughout the trip back home (ECO mode)
- 3.2 mi/kWh for total trip in the end
- 10F outside home.

- battery temp was 4 bars throughout the trip

Honestly, when I saw 6 bars and 44 mi left in GoM once I reached my destination, I was thinking driving back 25 mi to home shouldn't be an issue. I then realized that I used CC only for the last 7 mi of onward journey, and used up 6 battery bars. Anyways, I just wanted to see how far I can go and if batt bars got low, I can turn CC off and can get off the highway & take a slightly longer back-road.

I had some extra clothing to put on if it boils down to turning off CC Glad I didn't have to do that. And, glad I didn't turn CC on sooner or made that extra pitstop - those would've cut it too close. And I probably would've been fooled by battery bars/GoM.

Glad it worked out OK. I wouldn't hesitate to do this trip again (I may end-up having to do this trip every week), of course, with no other pitstops, at least not until it gets warmer than now!

Jay - yes, you are very correct. How often have I/we did any hypermiling on ICE car? Maybe very occasionally! Like someone mentioned to me, cars like Leaf are more like video games. You strive to achieve better scores always!

Finally, FWIW, here is some statistics I collected during the trip:

Trip odometer   Battery bars left    GoM (ECO Mode)
0                         12                 90
8                         11                 67
18                         9                 61
18.8                       8                 52    <-- CC turned on
25.3                       7                 45
31.8                       5                 34
42                         2                 11
49.2                       1 LBW              5
50.4                       1 LBW              4

 

[TonyWilliams]

Great trip! So, at 10F (assuming the battery was that temp), equals 15% ding on battery capacity,

21kWh for a new battery - (21 * 15%) = 17.85kWh stored capacity with zero degradation.

17.85 * 3.2 miles/kWh = 57.1 miles range autonomy

You drove 50.4. Going past LBW for 1.5 miles at 3.0 miles/kWh (or less) leaving 6.7 miles to go (57.1 - 50.4 = 6.7). Range Chart from LBW for 3.0 miles/kWh is 9 miles range, minus 1.5 past LBW equals 7.5 miles remaining.

50.4 + 7.5 = 57.9 miles range versus 57.1 miles calculated above. Eh, not bad for guessing, huh?

Your original post:

By CarWinger energy use -> 57.6 mi
By TonyWilliams's chart -> 57.8 mi

Heck, even I'm impressed. :mrgreen:

Remember that to average 3.2 overall after previously going 3.8 means you were significantly lower than 3.2 on the return leg with that heater blasting!!!

 

[mkjayakumar]

The big question is: what is more important your adventuring nature to show that is possible or gallons of gas that are not used for that trip, or both?

Actually it is the fact that I have come to hate driving an iCEv and burning gas. That is what keeps me in the Leaf, even if the trip takes much longer.

Venk and I actually go a long way when we both were colleagues and lived in NH for several years. He stopped by at my house in Plano on Christmas day last month, heard my pitch on the Leaf but never got to even sit in the car and drive it, because of all the unusual snow and very bad roads here. And then two weeks later I got an email from him stating he leased a Leaf !!

 

[tps]

My LEAF has been doing GREAT in the 10-20 degree weather we've had this week here in Philly. I'm still charging it to 80% overnight, but I'm also charging on 120V while I'm in the office. With the LEAF there is no warmup; performance is the same for the first 10 feet as it is for the rest of the drive. Now that's a change from my previous experience with cars... And with the heated seats and steering wheel, I haven't even bothered to pre-heat the cabin; it heats up fairly quick (CC drawing 4.5 kW) once I get going.