IS THIS NORMAL FOR A LEAF?

ELROY said:

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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All my numbers were "from the wall" numbers - I generally estimate about 21 kWh usable for a new LEAF.

If we estimate that your LEAF took 23.9 kWh from the wall to charge from turtle to 100% and knowing that a new LEAF might take a bit more than 25 kWh to charge from the wall (let's use 25.4 kWh from the NREL paper), that puts your LEAF at about 6% down in capacity from a new LEAF. Note that this is a guess as we don't know the actual energy that was put into the car from the wall.

Knowing that capacity degrades the fastest when the car is new, I am guessing that it is expected, though someone might get the actual number using the battery aging model. We would need to know the manufacture date of the vehicle to figure this out.

ELROY said:

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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Don't forget that you said the temps were 50-60 F. If the battery were 50 F (plausible given overnight parking outside), Tony's range chart says "Subtract 1% from range for each 4F/2C below 70F/20C", so (70-50)/4 x 1% = 5%. I've observed that the battery has a significant thermal lag, and up here even with summer daytime temps approaching 90-100, my battery stay pretty cool if I keep the car shaded during the day and park outside at night (we cool off pretty good here at night due to a desert-like climate).

Reddy

Did some more testing tonight. Last weekend was the first time I ran the LEAF down to turtle mode. Tonight was the first time I ran the LEAF all the way down to the point where I had to push it back home!
Test Results:

65.4 miles: Low Battery Warning (4.1 mi/kWh avg to this point)


75.1 miles: Very Low Battery Warning (4.2 mi/kWh avg to this point)



82.4 miles: Turtle Mode (4.2 mi/kWh avg to this point)


83.0 mile: Car will not move or shift into "D" (4.3mi/kWh avg to this point)


Based on Tony's range chart, I should be getting about 89 miles with a 281 GID new battery pack
my 82.4 miles till turtle (at 4.3 mi/kWh) seems to match his 93% battery capacity chart. So for a 5 month old LEAF with 3924 miles, do I have a legitimate basis to complain to Nissan? I mean, its almost as if I am missing 1 bar of charge capacity.
Secondly, if your battery capacity goes down to 93%, do you just lose that 7% off the top? Or do you lose 7% or range even when charging up to 80% capacity?

Morning after this test:
6.55hr (6hr 33minutes): Time to charge the car to 100% again from dead, beyond turtle.
Shouldn't it take longer than this? Isn't there a way to extrapolate battery capacity by charge time?
6.55hr x 3.3kw=21.61kWh at the most...assuming constant full charge rate. What are others getting for full L2 charging from empty to 100%?

Yes, it sounds like you've got some degradation, or the temperature was much colder than weather.com's listing of Hi 70°F, Lo 46°F for Friday.

Here's my similar run, 4.3 mi/kWh, 80.5 mi, but at 28-32F:
http://www.mynissanleaf.com/viewtopic.php?f=31&t=7634&p=243033&hilit=cold#p243033

Reddy

Reddy said:

Yes, it sounds like you've got some degradation, or the temperature was much colder than weather.com's listing of Hi 70°F, Lo 46°F for Friday.

Here's my similar run, 4.3 mi/kWh, 80.5 mi, but at 28-32F:
http://www.mynissanleaf.com/viewtopic.php?f=31&t=7634&p=243033&hilit=cold#p243033

Reddy

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Good stuff. So prob 22kw charge into your battery considering 85% efficiency? How many amps does the level one pull. Around 12amps? How many miles are on your car?

ELROY said:

Good stuff. So prob 22kw charge into your battery considering 85% efficiency? How many amps does the level one pull. Around 12amps? How many miles are on your car?

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Our power is very clean here, always 60 Hz, 120VAC. The car pulled 12.0 amps every time I looked at the kill-a-watt meter, so 1.44 kW. I think the 85% efficiency may be just a touch high given the colder temps. Assuming 21 kWh (and it may be even lower at those temps), that's closer to 82-83%. At the time of my run, the car was 15mo old and had about 8500 mi. Now I'm at 19 mo and 10,500 mi. Here's the more complete info. Sorry, I had the pointer wrong on my other post, I'll fix it.
http://www.mynissanleaf.com/viewtopic.php?f=31&t=6876&start=160#p243034

Reddy said:

ELROY said:

Good stuff. So prob 22kw charge into your battery considering 85% efficiency? How many amps does the level one pull. Around 12amps? How many miles are on your car?

Click to expand...

Our power is very clean here, always 60 Hz, 120VAC. The car pulled 12.0 amps every time I looked at the kill-a-watt meter, so 1.44 kW. I think the 85% efficiency may be just a touch high given the colder temps. Assuming 21 kWh (and it may be even lower at those temps), that's closer to 82-83%. At the time of my run, the car was 15mo old and had about 8500 mi. Now I'm at 19 mo and 10,500 mi. Here's the more complete info. Sorry, I had the pointer wrong on my other post, I'll fix it.
http://www.mynissanleaf.com/viewtopic.php?f=31&t=6876&start=160#p243034

Click to expand...

Just a reminder that 120 Volt, 12 Amp charging is less efficient than Level 2 charging. It has been measured at roughly 75% in 2011/2012 LEAFs. (Whether the efficiency has changed at all in the 2013 hasn't been determined, so far as I am aware.) 240 Volt 16 Amp charging was determined by NREL to be about 86% efficient, which is a good match for those of us who have looked at it. The faster charging on a 2013 LEAF, with that option, can be expected to be even more efficient. The reason for this is that the fixed overhead while charging—cooling pumps, for example—is experienced for a shorter time.

When looking at charging efficiency remember that the efficiency drops as one approaches 100% because charging slows, so there is more overhead. Those of us who rarely charge to 100% will have somewhat higher charging efficiency, which is what I see.