Couldn't make it

[kolmstead]

Jumped in my Leaf this morning and headed off to work, just as I've been doing for 35 months. Twenty degrees outside, but nice and warm in the Leaf. After about six miles, I turned around, drove home and got my truck. GOM was dropping like a rock, but more importantly, I couldn't get my miles per kWh above 3.0. First time my Leaf couldn't safely do the job I bought it to do.

Leaf number 257. I always preheat in the winter, and drive in ECO mode with AC off, temp set to 61 degrees. ECO limits heater power consumption to about 1500 W. Several things were working against me. Installed new Michelin Primacy tires about three weeks ago, and saw an immediate drop in efficiency. I was averaging 4.8 mpk before, now I'm lucky to get 3.9. And I preheat just long enough to make the cabin comfortable. The heater probably draws 4-5 kW at first, so the on-board charger can't keep up. I've seen a drop of two or three Gids from normal 100% readings, presumably due to preheating. So, loss of efficiency due to tires and some battery discharge due to preheating. Oh, yeah, two bar loser, roughly 25% loss of battery capacity because I live in the Mojave Desert. Turbo3's battery app was showing about 72% capacity remaining this summer; now 76%. And let's not forget battery temperature. I failed to check battery temp with Turbo3's app, but the car showed four bars. Probably 45 degrees or so, considering 20 degrees outside and charging terminated a couple of hours before I drove it. Tony Williams' range chart says to deduct 1% for every 4 degree F temp reduction below 70F. So maybe 12% today.

Commute today about 40 miles, 35 ordinarily.

After I got to work, I wondered if my gut feel was right, or I was just an old fuddy-duddy. Can't argue the old part. Being an engineer, I started running numbers. We know that the Leaf when new has about 21 kWh usable capacity. If my capacity is truly 76% of a new Leaf, then it was probably about 64% today because of the cold. I was getting about 3 miles per kWh. So my maximum range (to turtle) was about 0.64 * 21 * 3, or 40 miles. Good thing I turned around. It's important to keep a healthy reserve, especially when outside conditions are severe.

New strategy. If the temp is over 25 or so, it is probably OK to drive the Leaf. If it's colder, or I need to go further, I'll have to drive something else. Maybe my Leaf will be usable next summer and fall. After that, I'll get a new battery or it'll go to a charity. In less than four years. Sad. I thought, with a 35 mile commute, that it would be good for ten years.

-Karl

 

[ericsf]

Had a similar feeling yesterday on my way back from work (no option to turn around). The temp was in the low 40s and when I noticed that I had already lost 3 bars where I'd normally still have 11 up, I got worried. Turned OFF the heater and slowed down to 55. It's not new that cold takes a big hit on the LEAF's range but it's indeed scarry when you're used to making the same trip effortlessly and bang, you can't. I guess that's what the cold weather packaged is for...

 

[DaveEV]

Sorry to hear that Karl - major bummer.

Some thoughts:

Tires: 4.8 -> 3.9 mi/kWh is a HUGE hit in efficiency due to those tires. Some possibilities - inflate the tires to whatever the max on the sidewall is. If that doesn't help, perhaps ditch the Primacy tires and find some Ecopias. Perhaps someone will even trade, but may be difficult to find someone out there in Ridgecrest.

Charging/Pre-heating: Can you time the charge to end even closer to departure time - say within 1 hour instead of 2? That may help keep the battery a tiny bit warmer for your drive. Also, if you pre-heat for longer, you should not lose any charge - do you use the timer for this, too, or do you manually turn it on? You might try pre-heating for an hour or so.

Driving Style: Can you slow down any more? 5 mph should pick up 10% more range. If you can also avoid running the heat at all, you should be able to pick up another 5-10% more range. Perhaps install aftermarket seat warmers to make up for the lack of cabin heat?

 

[LeftieBiker]

What pressure are you running the snows at? You might not even need to go to max pressure - 40psi seems to make a big difference. You can always drop it in bad weather. Someone needs to come up with a good aftermarket AC (or maybe even propane) cabin heater, especially for the non-heatpump Leafs!

 

[TickTock]

Little Buddy?

What pressure are you running the snows at? You might not even need to go to max pressure - 40psi seems to make a big difference. You can always drop it in bad weather. Someone needs to come up with a good aftermarket AC (or maybe even propane) cabin heater, especially for the non-heatpump Leafs!

 

[KillaWhat]

You might consider a GID meter (Leaf DD?. etc.)
It really changed the way I drive.
I actually KNOW what is in the pack.
I often have the GOM showing something like 11, and and the GID meter shows me that I still actually have say 23% left in the pack.

Good Luck.

 

[adric22]

I awoke to this scene this morning here in Ft.Worth. I can't imagine what this sleet would do to my rolling resistance. I'm sure the heater combined with this drag would really kill my energy efficiency.

Fortunately, my work and my daughter's school are closed anyway.

 

[ksnogas2112]

Yesterday, left the house(garage) the air temp in the garage was 55 and I had 5 battery temp bars, 11 GOM range bars. I drove to the office, lunch and home. 18 miles. Arrived home with 6 GOM range bars and 3 battery temp bars. I knew I wasn't driving very many miles and used the heater.

This morning air temp in garage was 45 and there were 4 battery temp bars. I charged to 100%. Drove to the office with heat running, real air temp 10F* and used 2 full GOM range bars (7 miles). Avg speed both days 45 mph.

Back in May when we went from 60*F to 12 inches of snow over night I went from 4.5 m/kwh to 3.5 m/kwh due to cold battery, cold air, and a little bit of heater. That m/kwh was over the exact same route and exact same driving style and the streets had been plowed of snow so that wasn't an impact.

Cold sucks (as we've posted before).

 

[kolmstead]

The Primacys were at 40 psig according to my tire gauge; LeafSpy says 42 while driving. 100% charge w/o preheat is about 207 Gids; about 203 if I do my usual quick preheat. I use end timer set one hour late for charging, but I could go a little more. I have a problem with preheating for an hour; that's quite a waste of power for a 'green' vehicle. I'll have to download some TED energy consumption data and see what the optimal times would be. Used that data to set up my present timers, but I had a much better battery then. I think getting the battery warmer has the most potential for extending my range.

I was appalled when I realized how much effect the new tires had, particularly since the numbers people have reported on MNL have been around 5-10% loss in efficiency. For the first few days after the installation, I thought I had a major battery failure. Then I noticed the horrible mpk numbers. Part of that loss was undoubtedly due to colder weather. Haven't decided what to do about the tires. As noted, too far from other Leaf drivers to make a swap easy.

Yes, if necessary I can shut off the heater, but that's not going to be fun at 20 degrees outside. I am driving 10 mph below the speed limit on the first third of the trip, and I could chop another ten off once I get on the military base. It's one thing to take those steps occasionally to stretch the range, but when they become daily requirements, I think we've reached 'end of useful life'.

Some of my decisions hinge on the BIG QUESTION. Will my car qualify for battery replacement in 2014? I may be able to limp through the remainder of this winter, but I won't be driving the car next winter w/o a new battery. It took me a full year to lose the second capacity bar; at that rate, it'll lose the third this coming July. After that, the car will be yard art.

-Karl

 

[DaveEV]

The Primacys were at 40 psig according to my tire gauge; LeafSpy says 42 while driving.

Getting them up another couple PSI won't hurt. Aim for 44 - the Primacys should be rated for that.

I have a problem with preheating for an hour; that's quite a waste of power for a 'green' vehicle. I'll have to download some TED energy consumption data and see what the optimal times would be.

I don't think it will be too bad - power should taper off fairly quickly. Yes, if you can use the TED you should be able to figure out the optimal pre-heat time that lets you keep a full charge.

I think getting the battery warmer has the most potential for extending my range.

Battery warmer? The battery warmer in the LEAF doesn't do anything until the electrolyte is in danger of freezing. Doesn't get cold enough for that in California. What temps does LEAF Spy have your battery at?

Yes, if necessary I can shut off the heater, but that's not going to be fun at 20 degrees outside.

Does it get too cold even with preheating on the way to work?

I am driving 10 mph below the speed limit on the first third of the trip, and I could chop another ten off once I get on the military base. It's one thing to take those steps occasionally to stretch the range, but when they become daily requirements, I think we've reached 'end of useful life'.

Yeah, doesn't seem like you can drive much slower.

Some of my decisions hinge on the BIG QUESTION. Will my car qualify for battery replacement in 2014? I may be able to limp through the remainder of this winter, but I won't be driving the car next winter w/o a new battery. It took me a full year to lose the second capacity bar; at that rate, it'll lose the third this coming July. After that, the car will be yard art.

Well, with the heat there in Ridgecrest, all you should have to do is leave the battery sit longer at 100% in the summer...

Too bad you can't charge at/near work. That would eliminate any range issues.

 

[KJD]

When I pulled into the parking lot at work today the eyebrow temp said 6f. Range is not so good on these days.

In view of the poor winter performance what is your vote for battery pack size ?

Record your vote http://www.mynissanleaf.com/viewtopic.php?f=27&t=15103" onclick="window.open(this.href);return false;

 

[smkettner]

Depending on where you are on time and miles to the battery capacity warranty you may want to keep the low efficiency tires to get down four bars before the warranty expires.

 

[kolmstead]

So far, so good. Made it home safely two days in a row with morning temps around 18F. Today I drove a little further and hit LBW at 38 miles. Preheated as usual and ran the heater set to 61 all the way to work, with draw limited to 1.5 kW by ECO mode. Once it exhausted the pre-heat, the heater turned on and never cycled again. Cabin cooled off quickly; it was probably in low 50s by the time I got to work. It was sunny today, so I left heater off on the way home.

After yesterday's 35 mile commute, the car had 59 Gids remaining. Don't remember yesterday's mpk; today's was 3.6 miles/kWh.

Haven't gathered TED data yet to plan longer preheat or schedule charging to preheat battery more; maybe tomorrow. Battery temp 3 bars both mornings.

Looks like I can still do my commute, as long as I don't encounter a headwind, or drive more than a mile or two extra. Managing the heater is important. Don't like being this close to the limit, especially when it's cold and dark out.


-Karl

 

[walterbays]

Tires: 4.8 -> 3.9 mi/kWh is a HUGE hit in efficiency due to those tires. Some possibilities - inflate the tires to whatever the max on the sidewall is. If that doesn't help, perhaps ditch the Primacy tires and find some Ecopias.?

As TomT pointed out http://www.mynissanleaf.com/viewtopic.php?p=342186#p342186 it's not just the switch from Ecopia to Primacy that lowered our efficiency; it's also the switch from old tires with worn tread to new tires with full tread. Besides tires, cold, and battery degradation, a fourth factor that lowered our efficiency is the Nissan software update that reduces regeneration, sometimes drastically.

Here's my list of possibilities to maintain my car's usability, some of which might not apply in your situation:

1. Workplace charging - if building owner decides to install L2 nearby. Cost: $1-2 per day that I need a little extra range

2. evGo quick charging subscription. Cost: $180/yr

3. Switch back to Ecopia tires and resign myself to replacing them every 1 year or 10,000 miles. Cost: $450/yr

4. Nissan sells me a reasonably priced new battery, heat resistant, improved durability, and higher capacity. Cost: unknown

5. Trade in Leaf on a new Chevy Volt. Cost: a lot

6. Trade in Leaf on a new Leaf *LEASE*. Cost: a lot

7. Rent a moderately degraded battery from Nissan. Cost: $1,200/yr

 

[abasile]

Yes, if necessary I can shut off the heater, but that's not going to be fun at 20 degrees outside. I am driving 10 mph below the speed limit on the first third of the trip, and I could chop another ten off once I get on the military base. It's one thing to take those steps occasionally to stretch the range, but when they become daily requirements, I think we've reached 'end of useful life'.

I am with you. On an occasional basis, I enjoy the challenge of stretching the range of the LEAF to accomplish longer drives. On a day to day basis, it gets old quickly.

My personal opinion is that offering at least two battery size options would be the way to go for Nissan in the future. I don't even think it's worth bothering with anything smaller than 36 kWh; that would be the smaller size battery.

 

[ColumbiaRiverGorge]

I am with you. On an occasional basis, I enjoy the challenge of stretching the range of the LEAF to accomplish longer drives. On a day to day basis, it gets old quickly.

My personal opinion is that offering at least two battery size options would be the way to go for Nissan in the future. I don't even think it's worth bothering with anything smaller than 36 kWh; that would be the smaller size battery.[/quote]

I second this. It seems spring & fall are my seasons with better range. In the winter (studs, outside temps inefficient heater) I get 2.7 m/Kwh & in the summer a strong headwind also equals 2.7 m/Kwh. I also have 2000' climb per day with speeds of 55 to 65.

 

[kolmstead]

One more piece of the puzzle. I checked my battery this morning before the preheat cycle started. 208 Gids. When I climbed in the nice, warm car to go to work... 190 Gids. The abbreviated preheat cycle I've been using cost me 18 Gids, about 9% of my capacity! As we discussed before, the heater draws up to 6 kW until it gets the heat exchanger fluid hot. Since the 2011 Leaf onboard charger can only supply 3.3 kW, the rest has to come out of the battery. Also noted battery temp this morning; 42 degrees.

I have the preheat timer set late, ten minutes after I actually leave for work, in the hopes of minimizing wasted energy and keeping the car from getting excessively warm. Didn't think about the battery needing time to recover. Tonight I should be able to download TED data and find out what time the charging and the preheat cycles begin.

Takes a lot of instrumentation to keep track of a Leaf!

-Karl

 

[DaveEV]

I checked my battery this morning before the preheat cycle started. 208 Gids. When I climbed in the nice, warm car to go to work... 190 Gids. The abbreviated preheat cycle I've been using cost me 18 Gids, about 9% of my capacity!

I have the preheat timer set late, ten minutes after I actually leave for work, in the hopes of minimizing wasted energy and keeping the car from getting excessively warm. Didn't think about the battery needing time to recover. Tonight I should be able to download TED data and find out what time the charging and the preheat cycles begin.

Ouch, yeah, 18 GIDs would be good for around 5 miles - perhaps less in the cold. Should see how far 18 GIDs gets you on your commute.

 

[bowthom]

Hello,
Been watching my regen pretty closely as of late. It seems to me when the outside temp gets below freezing the leaf limits regen in favor of anti skid controlled braking of all four wheels. I turned traction control off but regen did not increase. This is not an empirical study, just random thoughts about it's behavior.

Don

Tires: 4.8 -> 3.9 mi/kWh is a HUGE hit in efficiency due to those tires. Some possibilities - inflate the tires to whatever the max on the sidewall is. If that doesn't help, perhaps ditch the Primacy tires and find some Ecopias.?

As TomT pointed out http://www.mynissanleaf.com/viewtopic.php?p=342186#p342186 it's not just the switch from Ecopia to Primacy that lowered our efficiency; it's also the switch from old tires with worn tread to new tires with full tread. Besides tires, cold, and battery degradation, a fourth factor that lowered our efficiency is the Nissan software update that reduces regeneration, sometimes drastically.

Here's my list of possibilities to maintain my car's usability, some of which might not apply in your situation:

1. Workplace charging - if building owner decides to install L2 nearby. Cost: $1-2 per day that I need a little extra range

2. evGo quick charging subscription. Cost: $180/yr

3. Switch back to Ecopia tires and resign myself to replacing them every 1 year or 10,000 miles. Cost: $450/yr

4. Nissan sells me a reasonably priced new battery, heat resistant, improved durability, and higher capacity. Cost: unknown

5. Trade in Leaf on a new Chevy Volt. Cost: a lot

6. Trade in Leaf on a new Leaf *LEASE*. Cost: a lot

7. Rent a moderately degraded battery from Nissan. Cost: $1,200/yr

 

[thankyouOB]

One more piece of the puzzle. I checked my battery this morning before the preheat cycle started. 208 Gids. When I climbed in the nice, warm car to go to work... 190 Gids. The abbreviated preheat cycle I've been using cost me 18 Gids, about 9% of my capacity! As we discussed before, the heater draws up to 6 kW until it gets the heat exchanger fluid hot. Since the 2011 Leaf onboard charger can only supply 3.3 kW, the rest has to come out of the battery. Also noted battery temp this morning; 42 degrees.

-Karl

i have never seen the heater go above 4kw, and mostly <3 on the scale under energy consumption window.
is that because i dont get temps below 45 degrees here much when i heat a cold car in socal?