12% capacity loss in 9 months is "normal"

[klapauzius]

Thanks everyone for their support and inputs. I was wondering if my posting would "shake loose" any other Leaf owners with similar issues. It doesn't appear to be. I am glad my experience is an anomaly since I very much desire Nissan's success in their bold venture and do not wish any negative publicity. I will continue to attempt to resolve this outside the forum. Hopefully, I can follow up with some good news in the future.

Keep in mind that not everyone has a gid-meter, so a lot of people might not be aware
of this problem, if it existed.

 

[edatoakrun]

Keep in mind that not everyone has a gid-meter, so a lot of people might not be aware
of this problem, if it existed.

Well, you don't really need a gid-meter to see a problem like this. When TT did do a range test last week, the results were clearly below Nissan's estimates, and by about the same percentage as shown by the gid-meter.

But I also have been wondering, if there could be other unreported instances of similar range/battery capacity problems, since it really isn't a problem, for many LEAF drivers.

A week or so back, I expressed the opinion that this big a miss in range would probably be noticed immediately by most LEAF owners, but I'm not so sure, now that I've given it more thought. My LEAF might have been on a flatbed back to the dealer, the day after I picked it up, after it failed the 90 mile "test" on the longest leg, of my drive home, and any large range loss since, would have been immediately noticed, in my regular use.

But there are, I expect, many who never even touch the last 20% of the LEAF range, and would not have noticed the same level of range deficiency, if they had it.

I would advise any LEAF owner to check range against Nissan's estimates soon after delivery, and occasionally thereafter.

IMO, If you do have a shortfall in range, it's advisable to bring it to Nissan's attention as early as possible, since, if it's not a problem for you now, it could be in the future.

 

[garygid]

It is almost impossible to do any "drive" and claim that the achieved distance from "full" to LBW was too short. There are just too many variables involved.

Perhaps slightly easier to claim that charging from LBW to "full" used too little energy from the wall. But, there are still a number of significant variables.

 

[planet4ever]

It is almost impossible to do any "drive" and claim that the achieved distance from "full" to LBW was too short. There are just too many variables involved.

I'm not sure I agree, Gary. Shouldn't (miles driven) / (miles/kWh) give you a fairly good estimate, +/-3%, of kWh actually used out of the battery? If you do it without climate control the only other major variable I can think of is battery temperature.

For what it's worth, I just charged tonight after driving 60.9 miles in three days with 4.5 m/kWh. I started at 80% and ended just above VLBW (GOM=3 when I arrived home, three bars when I turned it off and back on, 18 hour est. to charge to 80% at 120v). So far as I can remember, the only climate control I used was the fan. The car lives outside and the battery has been holding steady at 5 bars for at least two weeks. I charge at night, it stopped at 3:52 AM on Apr 2 (no I haven't had the service upgrade), and the low temp here that night was about 48°F.

(60.9 miles) / (4.5 m/kWh) = 13.5 kWh.
80% to VLBW should be about 70%-75% of usable capacity, so usable <= 13.5 / 0.7 = 19.3 kWh
Tony estimates (70-48) / 4 = 5.5% range loss for temperature, so 70° usable would be <= 19.3 / 0.945 = 20.5 kWh.
The low end of the range might be (13.5 / 0.75) / 0.95 = 19 kWh.

So it looks like I have a normalized capacity of somewhere between 19 and 21.5 kWh. That seems slightly low, though less than 10% low. I would want to do this sort of calculation several times, including with warmer temperatures, before getting alarmed.

And, yes, I do intend to get Phil's LEAFSCAN, which will give me much better data. My intent here was to suggest you can get a good idea of battery capacity without any special equipment.

Ray

 

[edatoakrun]

"garygid"]It is almost impossible to do any "drive" and claim that the achieved distance from "full" to LBW was too short. There are just too many variables involved...

Sorry to disagree, but if you see this, near 16 kWh from 100% charge to VLBW (except from a very cold battery), I'd suggest further inquiry, and depending on what you find, maybe a trip to the dealer to have it checked out.

Tick Tock...I had the opportunity to take it to VLBW today after my 100% charge this morning. 75.2 miles, "---" on the GOM, 4.6 mpkWh efficiency....

http://www.mynissanleaf.com/viewtopic.php?f=31&t=8331&start=140" onclick="window.open(this.href);return false;

But I admit, at the moment, to be unsure as to what the LBW might mean, in certain conditions.

"...I did not...get the LBW until I actually parked, in my carport, stopped and restarted..." (this was 0.4 miles after losing the second bar).

I've never before had the LBW on start-up, that had not also occurred, during the previous trip. Do I use it, as a indication of SOC, or not?

http://www.mynissanleaf.com/viewtopic.php?f=31&t=8420&start=10

 

[EVDRIVER]

Thanks everyone for their support and inputs. I was wondering if my posting would "shake loose" any other Leaf owners with similar issues. It doesn't appear to be. I am glad my experience is an anomaly since I very much desire Nissan's success in their bold venture and do not wish any negative publicity. I will continue to attempt to resolve this outside the forum. Hopefully, I can follow up with some good news in the future.

Very good idea. I suppose you have decided not to contact everyone in the world that has nothing to do with your issue like the EV project and you have already tried running your car on blocks until dead and charging back up, driving next to five LEAFs, calling the press, and charging your car to 100% while placed on rubber blocks and measuring it with a Gid meter with an oxygen free cable? I called the EV project when I had some tire wear issues and they got me two front tires!

Here is the obligatory :lol: for those that need it.

 

[DaveinOlyWA]

It is almost impossible to do any "drive" and claim that the achieved distance from "full" to LBW was too short. There are just too many variables involved.

I'm not sure I agree, Gary. Shouldn't (miles driven) / (miles/kWh) give you a fairly good estimate, +/-3%, of kWh actually used out of the battery? If you do it without climate control the only other major variable I can think of is battery temperature.

Ray trip info can be used as a guideline but no one trip is that valuable. if you track say 10 trips that are similar like a work commute, ok them the average is 10 X more valuable than the one trip but there is still too many outside inference factors to consider.

i lose at least .2 miles/KW when the family is in the car. all that has to be taken into consideration. as far at Tick Tock's issues, the GID count is all the information you need. he just does not get a full recharge.


as far as finding it. it is true, unless you are in the habit of driving to the max range, you might not ever notice it and Tick Tock was a perfect example. he was well within the 80% range so he rarely fully charged, rarely saw less than 2 bars when he did get around to recharging, etc.

there are a lot of people (in fact most people...not all are like Tony, Casey and few others who pile on the mileage like there is no tomorrow) that fit his "drive no more than 25-40 miles a day" profile.

 

[TickTock]

Thanks everyone for their support and inputs. I was wondering if my posting would "shake loose" any other Leaf owners with similar issues. It doesn't appear to be. I am glad my experience is an anomaly since I very much desire Nissan's success in their bold venture and do not wish any negative publicity. I will continue to attempt to resolve this outside the forum. Hopefully, I can follow up with some good news in the future.

Keep in mind that not everyone has a gid-meter, so a lot of people might not be aware
of this problem, if it existed.

My guess is if there are many others in the general public with similar issues, at least a few would find (through Google) themselves here and consider the tool purchase.

 

[garygid]

"claim the achieved distance ... too short"

 

[TickTock]

It is almost impossible to do any "drive" and claim that the achieved distance from "full" to LBW was too short. There are just too many variables involved.

I'm not sure I agree, Gary. Shouldn't (miles driven) / (miles/kWh) give you a fairly good estimate, +/-3%, of kWh actually used out of the battery? If you do it without climate control the only other major variable I can think of is battery temperature.

Ray trip info can be used as a guideline but no one trip is that valuable. if you track say 10 trips that are similar like a work commute, ok them the average is 10 X more valuable than the one trip but there is still too many outside inference factors to consider.

i lose at least .2 miles/KW when the family is in the car. all that has to be taken into consideration. as far at Tick Tock's issues, the GID count is all the information you need. he just does not get a full recharge.


as far as finding it. it is true, unless you are in the habit of driving to the max range, you might not ever notice it and Tick Tock was a perfect example. he was well within the 80% range so he rarely fully charged, rarely saw less than 2 bars when he did get around to recharging, etc.

there are a lot of people (in fact most people...not all are like Tony, Casey and few others who pile on the mileage like there is no tomorrow) that fit his "drive no more than 25-40 miles a day" profile.

For me, the tell was regularly getting the Low Battery Warning at the end of an easy, flat, 50mph, 48 mile round trip on an 80% charge. During the summer, I irrationally told myself it was the heat and the AC use but once summer ended that explanation didn't hold up.

 

[garygid]

If Ingineer would tell us about the Nissan's "Pack Capacity" value
in the CAN data, I could add that data to the GID-Meter's display.

The same goes for the Pack Temperature(s) and Tire Pressures.

 

[Weatherman]

It appears I can add my LEAF to the diminished-usable-battery-capacity-when-new list.

The car is a little over four months old and has 3,600 miles on it. After running a couple of range tests where the results were less than expected, I timed a charge last night. The battery started a couple of miles past LBW and charged to 100% in 5.33 hours on a Schneider L2 EVSE. No matter what kind of assumptions you make, a 5.33 hour charge time indicates there's less battery capacity between LBW and 100% than one would normally expect.

I read through this thread and the consensus seems to be that Nissan considers this diminished capacity to be within normal operating parameters. However, I do have to wonder how many people own LEAFs with diminished capacity batteries. I would hate to think I won the diminished-capacity-battery lottery when I bought the car.

It's a good thing I live in a warm climate with flat terrain and very rarely have to go anywhere near the single-charge range limit on the car.

 

[DaveinOlyWA]

I still think nissan will address the issue ok battery packs it seem to be quite a bit different than the normal I am currently running a sort of an experiment for the first 14 months I rarely if ever went to a full charge no because the job change I will be doing a full charge nearly everyday up to this point and 15,000 miles I have seen no battery degradation at all we will see how the full charging affects this parameter

 

[DaveEV]

The battery started a couple of miles past LBW and charged to 100% in 5.33 hours on a Schneider L2 EVSE. No matter what kind of assumptions you make, a 5.33 hour charge time indicates there's less battery capacity between LBW and 100% than one would normally expect.

Wait a minute. At LBW you still have 3+ kWh in the pack before dead. Without knowing your mi/kWh and range at LBW it's had to say whether or not you have reduced battery capacity or not.

 

[edatoakrun]

It appears I can add my LEAF to the diminished-usable-battery-capacity-when-new list.

The car is a little over four months old and has 3,600 miles on it. After running a couple of range tests where the results were less than expected, I timed a charge last night. The battery started a couple of miles past LBW and charged to 100% in 5.33 hours on a Schneider L2 EVSE. No matter what kind of assumptions you make, a 5.33 hour charge time indicates there's less battery capacity between LBW and 100% than one would normally expect.
....

Why do you say that this is an unexpectedly short charge time? That's a 16 amp L2, right?

When I do the math for 5.33 hours (or do you mean, 5 hours, 33 minutes?) 1 get about 17.4 kWh, 16 amp at 85% efficiency. the tapered charge rate at the end probably means you actually got less than this.

But without knowing more, what period of time, and at what charge rate, occurred at the end of charge, I don't see how you can figure out much, from the just the total time reported.

Check your CW reports for the calculated kWh used, for the same drive.

 

[TonyWilliams]

It appears I can add my LEAF to the diminished-usable-battery-capacity-when-new list.

You may or may not have this problem, and 98% of owners won't know if they do.

As I stated in the other thread, your methods to determine this are suspect. I posted a somewhat detailed method to get that baseline battery capacity data. Detailed, but simple. Drive from 100% to Turtle.

Please do that test, and post those results.

EDIT: here's the way I'd like the data presented so we can eliminate guessing and 20 questions as much as possible:


Checklist before the data collecting run:

1. (your answer) Any changes to car from stock (different tires, bike rack, Texas cattle horns, etc)
2. (your answer) Tire pressures set, heater and air conditioning off, car at 100% charge, cells allowed time to balance
3. (your answer) Gross vehicle weight? 3350 pounds plus operator, passengers, spare tire, bags, concrete, etc
4. (your answer) Route, length, elevation, hills if any, general conditions (dry, concrete/asphalt, etc)
5. (your answer) Assumed or measured battery temp (from LEAFscan tool)
6. (your answer) Ambient air temp
7. (your answer) Gid count at start, if available
8. (your answer) SOC, if available (from LEAFscan)
9. (your answer) Starting total voltage (should be 393.5v from GidMeter or LEAFscan tools)

Data to record:

1. (your answer) Outbound steady speed (confirm with cruise control on)
2. (your answer) Outbound observed steady speed miles/kWh from Nav adjusted -0.1
3. (your answer) Inbound steady speed (confirm with cruise control on)
4. (your answer) Inbound observed steady speed miles/kWh from Nav adjusted -0.1
5. (your answer) Miles at Low Battery Warning
6. (your answer) Miles at Very Low Battery
7. (your answer) Overall miles covered to Turtle
8. (your answer) Overall miles/kWh from dash economy display
9. (your answer) Calculated battery useable energy (miles / miles/kWh = battery kWh)
10.(your answer) Ending pack voltage, SOC, and Gid (350v-ish from GidMeter or LEAFscan tools)

 

[Weatherman]

Why do you say that this is an unexpectedly short charge time? That's a 16 amp L2, right?

When I do the math for 5.33 hours (or do you mean, 5 hours, 33 minutes?) 1 get about 17.4 kWh, 16 amp at 85% efficiency. the tapered charge rate at the end probably means you actually got less than this.

But without knowing more, what period of time, and at what charge rate, occurred at the end of charge, I don't see how you can figure out much, from the just the total time reported.

Check your CW reports for the calculated kWh used, for the same drive.

Ok, let’s run some numbers...

Assume that LBW is 49 gids (somewhere between 3.7 and 3.9 kWh), and I ran it a couple of miles past that, so lets say 3.5 kWh was left.

Let's also assume that the charger runs at full 3.3 kWh capacity for 5.33 hours (five hours, 20 minutes) to charge it back to 100% (probably not be true of the charge rate drops off as it approaches 100% full). So let's say 17.3 kWh to charge back to 100%.

So, conservatively, I have 3.5 kWh + 17.3 kWh for a full charge. That would be 20.8 kWh. If you assume 80 kWh per gid, that would be 260. You'd have to go with a 75 kWh per gid assumption to get 277 gids.

This is, certainly, not as bad as what TickTock is seeing, but is a bit less than I'd expect to see with a four-month-old car with 3,500 miles on it.

I'm going to take it into a local dealer, tomorrow, to see if they can find any defects. My expectation is that they will say nothing is wrong.

 

[TonyWilliams]

I'm going to take it into a local dealer, tomorrow, to see if they can find any defects. My expectation is that they will say nothing is wrong.

If you have time to waste, sure. But, you already know what the result will be.

You could spend your time actually gathering data (and not a whole bunch of calculated assumptions).

 

[DaveinOlyWA]

Full charge rate is 240 * 16 or 3840 Watts. Without a meter to measure your battery after a full charge u are really flying blind

 

[palmermd]

Ok, let’s run some numbers...

Assume that LBW is 49 gids (somewhere between 3.7 and 3.9 kWh), and I ran it a couple of miles past that, so lets say 3.5 kWh was left.

Let's also assume that the charger runs at full 3.3 kWh capacity for 5.33 hours (five hours, 20 minutes) to charge it back to 100% (probably not be true of the charge rate drops off as it approaches 100% full). So let's say (assumption) 17.3 kWh to charge back to 100%.

So, conservatively, I have 3.5 kWh + 17.3 kWh for a full charge. That would be 20.8 kWh. If you assume 80 kWh per gid, that would be 260. You'd have to go with a 75 kWh per gid assumption to get 277 gids.

This is, certainly, not as bad as what TickTock is seeing, but is a bit less than I'd expect to see with a four-month-old car with 3,500 miles on it.

I'm going to take it into a local dealer, tomorrow, to see if they can find any defects. My expectation is that they will say nothing is wrong.

Way too many assumptions....and it does not look like there is anything wrong to me. I'm going to assume you have 0% loss.