ELROY
Posts: 292
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Leaf Number: 023406
Location: Camarillo, CA

Re: IS THIS NORMAL FOR A LEAF?

Sun Mar 17, 2013 3:49 pm

So I am still kind of concerned that I can only reasonably expect 45-50 miles of driving before I hit the VLBW on an 80% charge.

I decided to do another reference test last night. I charged it to 100% and kept driving till I reached the Turtle Mode for the first time ever.
Results were as follows:

100% Charge
Tire Pressures: 48PSI
50-60F test temps (Always 5 battery bars)
Terrain: 160FT, fairly level driving. 60% city/40% highway.
No Heater...only a few minutes of A/C operation.

54.6 miles low battery warning

Image

63.5 Miles Very low battery warning (approx)

67.5 miles Turtle Mode

Image


3.5 m/kWh avg test economy

indicated dash charge time required:
25:00 hrs at 120v
07:30 hrs at 240v

Image

Actual Charge Time:
6hrs 37 minutes
(6.61 hrs)

Car is 4 1/2 months old and has 3841 Miles on it.
Is being able to drive 40-50 miles on 80% charge about all I can expect? (without driving with a feather foot as I did in my initial test results)

My main objective here is to determine whether or not I have a valid complaint to Nissan for low range for such a new car?

According to the range chart (Tony Williams). at 3.5 miles/kWh, I should have achieved about 73 miles perhaps. (till turtle).
And then may subtract another 3-4 miles for the 50-60F temps. So that would put me within a few miles of what I achieved.
And then 6.61hrs x 3.3kWh=21.78kWh approx into the battery. Is this correct, and right on the money on predictions for a new LEAF?

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surfingslovak
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Re: IS THIS NORMAL FOR A LEAF?

Sun Mar 17, 2013 4:04 pm

Image
ELROY wrote:indicated dash charge time required:
25:00 hrs at 120v
07:30 hrs at 240v
Just a quick comment: this exactly what we would expect from a new LEAF, and would imply 271 Gids on a full charge (or better). It's well understood and documented that the charging time display can drift and the displayed time can often have a 2 hours offset. That's in addtion to being inaccurate in terms of how long it actually will take to charge the vehicle. That said, assuming that the readout is accurate and the gauge did not have a drift, this bodes well for your LEAF.

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DaveEV
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Re: IS THIS NORMAL FOR A LEAF?

Sun Mar 17, 2013 4:38 pm

surfingslovak wrote:That said, assuming that the readout is accurate and the gauge did not have a drift, this bodes well for your LEAF.
In other words - at 3.5 mi/kWh, the range ELROY got is entirely expected on a fairly new LEAF. Need to improve the mi/kWh to get better range - slow down on the freeway! Going faster than 65 mph really hurts the range, so avoid it when you know you need the range. 3.5 mi/kWh is pretty low for southern California unless you are doing a lot of high speed driving.

LEAFfan
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Re: IS THIS NORMAL FOR A LEAF?

Sun Mar 17, 2013 4:44 pm

drees wrote:
surfingslovak wrote:That said, assuming that the readout is accurate and the gauge did not have a drift, this bodes well for your LEAF.
In other words - at 3.5 mi/kWh, the range ELROY got is entirely expected on a fairly new LEAF. Need to improve the mi/kWh to get better range - slow down on the freeway! Going faster than 65 mph really hurts the range, so avoid it when you know you need the range. 3.5 mi/kWh is pretty low for southern California unless you are doing a lot of high speed driving.
+1 Even at 65mph you should easily get 4.0 on level terrain.
2013 LEAF SV Del. 2/28/13
2013 LEAF World Record for Most Miles Driven On One Charge-188 miles/8.8 m/kW h
4.8 kW DC PV ($ .91/W fully installed)/ Dec., 2010

ELROY
Posts: 292
Joined: Sun Nov 04, 2012 10:36 pm
Delivery Date: 27 Oct 2012
Leaf Number: 023406
Location: Camarillo, CA

Re: IS THIS NORMAL FOR A LEAF?

Sun Mar 17, 2013 5:54 pm

surfingslovak wrote:Image
ELROY wrote:indicated dash charge time required:
25:00 hrs at 120v
07:30 hrs at 240v
Just a quick comment: this exactly what we would expect from a new LEAF, and would imply 271 Gids on a full charge (or better). It's well understood and documented that the charging time display can drift and the displayed time can often have a 2 hours offset. That's in addtion to being inaccurate in terms of how long it actually will take to charge the vehicle. That said, assuming that the readout is accurate and the gauge did not have a drift, this bodes well for your LEAF.
Is the fact that it only took 6.6hrs to charge instead of the 7.5hrs reason for concern of diminished battery capacity?
And it is probably true the charging tapers off making it even more likely that battery isn't taking a full charge. How long is it taking other owners to charge from turtle? Isn't is usually over 7hrs?

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DaveEV
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Re: IS THIS NORMAL FOR A LEAF?

Sun Mar 17, 2013 6:20 pm

ELROY wrote:Is the fact that it only took 6.6hrs to charge instead of the 7.5hrs reason for concern of diminished battery capacity?
And it is probably true the charging tapers off making it even more likely that battery isn't taking a full charge. How long is it taking other owners to charge from turtle? Isn't is usually over 7hrs?
No, all completely normal.

It usually takes up to 1.5 hours to charge from 80% to 100% and the LEAF will take about 4.5 kWh during that time. So 6.6-1.5 = 5.1 hours at full rate which is typically 3.8 kW for a total of 19.4 kWh. Add in the 4.5 kWh for 80-100% and you get 23.9 kWh which is just about what you'd expect for a 5 month old LEAF in southern California.

ELROY
Posts: 292
Joined: Sun Nov 04, 2012 10:36 pm
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Location: Camarillo, CA

Re: IS THIS NORMAL FOR A LEAF?

Sun Mar 17, 2013 6:57 pm

drees wrote:
ELROY wrote:Is the fact that it only took 6.6hrs to charge instead of the 7.5hrs reason for concern of diminished battery capacity?
And it is probably true the charging tapers off making it even more likely that battery isn't taking a full charge. How long is it taking other owners to charge from turtle? Isn't is usually over 7hrs?
No, all completely normal.

It usually takes up to 1.5 hours to charge from 80% to 100% and the LEAF will take about 4.5 kWh during that time. So 6.6-1.5 = 5.1 hours at full rate which is typically 3.8 kW for a total of 19.4 kWh. Add in the 4.5 kWh for 80-100% and you get 23.9 kWh which is just about what you'd expect for a 5 month old LEAF in southern California.
Of that 3.8kWh that goes into the charger, I believe only about 3.3kWh makes it to the battery. Besides, I don't think 23.9kWh would be accessible from our battery anyways? What is the capacity supposed to be on our batteries from full to turtle? In a new LEAF. Isn't it supposed to be around 22kWh?

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surfingslovak
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Re: IS THIS NORMAL FOR A LEAF?

Sun Mar 17, 2013 7:15 pm

ELROY wrote:
drees wrote:
ELROY wrote:Is the fact that it only took 6.6hrs to charge instead of the 7.5hrs reason for concern of diminished battery capacity?
And it is probably true the charging tapers off making it even more likely that battery isn't taking a full charge. How long is it taking other owners to charge from turtle? Isn't is usually over 7hrs?
No, all completely normal.

It usually takes up to 1.5 hours to charge from 80% to 100% and the LEAF will take about 4.5 kWh during that time. So 6.6-1.5 = 5.1 hours at full rate which is typically 3.8 kW for a total of 19.4 kWh. Add in the 4.5 kWh for 80-100% and you get 23.9 kWh which is just about what you'd expect for a 5 month old LEAF in southern California.
Of that 3.8kWh that goes into the charger, I believe only about 3.3kWh makes it to the battery. Besides, I don't think 23.9kWh would be accessible from our battery anyways? What is the capacity supposed to be on our batteries from full to turtle? In a new LEAF. Isn't it supposed to be around 22kWh?
I think this slide from NREL, which drees unearthed last year, sums it up really well. They have a properly instrumented lab, which we lack.

The rough efficiencies I'd use are:

charger: 92%
battery: 97%
drivetrain: 95%

Note that there is heat development in the battery both during charge and discharge, which will burn extra energy both ways. Applying these values, we get about 85% efficiency from the wall to the drivetrain, and about 80% wall-to-wheels. Keep in mind that approximately 0.5 kWh remains inaccessible in the battery when the contractor opens after turtle mode.


Image

ELROY
Posts: 292
Joined: Sun Nov 04, 2012 10:36 pm
Delivery Date: 27 Oct 2012
Leaf Number: 023406
Location: Camarillo, CA

Re: IS THIS NORMAL FOR A LEAF?

Sun Mar 17, 2013 8:03 pm

So even considering a 20% inefficiency, the EPA rates the range at 73 miles with a 2.9mi/kWh efficiency. With my 3.5 mi/kWh efficiency on this test, wouldn't it be at least eqaul to the EPA's 2.9 rating with 73 mile range? I know I'm not converting these exactly like the chart, but just giving it a general 20% inefficiency comparing the LEAF dash number to the EPA. I think I am being generous, (considering the LEAF dash number is not likely considering wall-wheel numbers), and I should at least get the 73 miles till turtle one would think.

If not, what is the equivalent of the EPA 2.9 mi/kWh to the LEAF cluster readout?

And again, if .5kWH in the battery is inaccessible. That should leave me with at least 23kWh of usable battery to turtle.

6.6hrs x 3.3kWh=21.78kWh of charge accepted into the battery. Perhaps I am missing about 1.2kWh of battery capacity, or about 5%?

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surfingslovak
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Re: IS THIS NORMAL FOR A LEAF?

Sun Mar 17, 2013 8:16 pm

ELROY wrote:So even considering a 20% inefficiency, the EPA rates the range at 73 miles with a 2.9mi/kWh efficiency. With my 3.5 mi/kWh efficiency on this test, wouldn't it be at least eqaul to the EPA's 2.9 rating with 73 mile range?
That's relevant, of course. The 2.9 m/kWh is wall-to-wheels efficiency, and I would expect to see something around 3.4 or 3.5 on the dash. So, yes, it should be comparable, even though it's an estimate. We don't have any accurate numbers to compare. It would be good to get the energy consumed in kWh from the wall, which should be the most relevant piece of data, aside from the distance covered.
ELROY wrote:That should leave me with at least 23kWh of usable battery to turtle.

6.6hrs x 3.3kWh=21.78kWh of charge accepted into the battery. Perhaps I am missing about 1.2kWh of battery capacity, or about 5%?
Sorry, I didn't catch this until now. Phil (aka Ingineer) confirmed that the battery is charged to about 95% of its rated capacity. While this yields 22.8 kWh, if you use the Gid count, it's a bit less: 281 x 80 Wh = 22.48 kWh. If we use 0.97% battery efficiency from the NREL report, this will yield about 21 kW out of the pack: 22.48 x 0.97 - 0.39 kWh = 21.42 kWh.

Note that the 0.39 kWh is based on 5 Gids remaining in the battery after turtle: 5 x 80 Wh x 0.97 = 388 Wh.

I think I can empathize with your point of view. When I was a new LEAF owner, I even called Customer Support and complained that my battery pack must be missing some capacity. This was based on the advertised rated figure of 24 kWh, of course.

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