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DaveEV
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INL L2 vs DC initial capacity test results after 50k mi+

Mon Sep 09, 2013 11:12 pm

Test details:
4 identical 2012 Nissan LEAFs
2 will be charged using only L2
2 will be charged using only DCQC
Battery packs will be tested every 10k miles for 30k miles.
2 additional battery packs will be lab tested at a constant 30C ambient - one only charged on L2, one only charged DCQC.

At 10k miles, no significant difference in capacity between L2 and DCQC - capacity is down between 5.5-6.5% approximately.

http://www4.eere.energy.gov/vehiclesand ... 2013_o.pdf" onclick="window.open(this.href);return false;

There are more interesting reports if you search the DOE Merit Review site:
http://www4.eere.energy.gov/vehiclesand ... it-review/" onclick="window.open(this.href);return false;
Last edited by DaveEV on Tue Apr 22, 2014 10:05 am, edited 2 times in total.
Reason: Updated title to reflect current status of test, read thread for new reports

phxsmiley
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Re: INL L2 vs DC initial capacity test results after 10k mil

Tue Sep 10, 2013 12:38 am

Really interesting report! I had lunch with a friend at Ecotality this week who was telling me about this testing, although he didn't know many of the technical details of this. It looks like the testing is being done from Oct 2012 until Oct 2013, so it must be still going on?

Sounds like they are doing testing immediately after driving AM/PM shifts, so they should get a really hot battery if DC charging during the hot time of the day, during the summer. It's very easy for me to get my battery pack up to 8 or 9 TBs using DCFC. And they'd need at least two DCFC sessions to get to about 140 miles a day.

I'm pleased at their findings so far, which seems to show very little degradation difference between an L2-charged car and a DCFC-charged car (slide 9). However, that was only at 10K miles, so they only had run from 10,000 miles / 140 miles/day (from their data) = 71 days. That would mean that run was from Oct 1, 2012 to about Dec 10th, 2012, if I'm understanding their testing correctly. This run would be to about Jan 1st, 2013 if they are doing 5 day work weeks, which I suspect.

October is in the upper 90s/low 100s max during the day, but the evenings are dropping to the 70s. Cooler yet in November and December, with December usually in the 70s during the day, 50s-60s in the night. The batteries will get a pretty low ambient temperature at night to cool off.

From the map, they have a decent mix of highway and side-street driving. The stretch of I-10 they are using will be very heavily congested in the early morning (7-9AM) and afternoon (3-7pm). If they are varying their time so that they sometimes avoid traffic, they will get times on I-10 that they are running at highway speed.

The 'third 10K' sample is the most interesting to me, as they should be doing several DCFC charges during the June-July-August timeframe and the ambient temperature stays high into the evening.
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edatoakrun
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Re: INL L2 vs DC initial capacity test results after 10k mil

Fri Sep 13, 2013 7:54 pm

Wish we already had the baseline constant speed track tests for each of the four LEAFs, as promised.


Looks like the six packs all tested ~ 2 to 3 percent below spec in static capacity when "new", at the BOT?

Technical Backup Slide 1
Test
Measureable
BOT

kWh Discharged (kWh)
23.40
23.47
23.31
23.59
23.38
23.24
http://www4.eere.energy.gov/vehiclesand ... 2013_o.pdf" onclick="window.open(this.href);return false;

IMO, if you are looking for some good data on early calendar aging, you might want to find the build dates for each of these LEAFs, and watch the results from the 10k, 20k, and 30 k mile capacity and range tests.
no condition is permanent

LEAFfan
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Re: INL L2 vs DC initial capacity test results after 10k mil

Fri Sep 13, 2013 8:07 pm

I'm not the least bit surprised with this data. I've been telling and posting about QCs since I started using them in Nov., '11. I knew that QCing a few times a day wasn't going to degrade the battery pack any more than any other multiple charging. With my 2011, I had QCd hundreds of times through 10,000 miles. I knew it wasn't the reason I had lost a CB, but high ambient temps over time caused it and because I drove mine the first six months at very low speeds, it kept it from losing the second CB.
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edatoakrun
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Re: INL L2 vs DC initial capacity test results after 10k mil

Fri Oct 25, 2013 11:08 am

phxsmiley wrote: ...Sounds like they are doing testing immediately after driving AM/PM shifts, so they should get a really hot battery if DC charging during the hot time of the day, during the summer. It's very easy for me to get my battery pack up to 8 or 9 TBs using DCFC. And they'd need at least two DCFC sessions to get to about 140 miles a day.


...The 'third 10K' sample is the most interesting to me, as they should be doing several DCFC charges during the June-July-August timeframe and the ambient temperature stays high into the evening.

There you go.

Results dated 8/7/13, showing both 20k and 30k mile results.

http://avt.inel.gov/pdf/energystorage/D ... et_30k.pdf" onclick="window.open(this.href);return false;

Too bad they don't seem to be posting the exact dates of the 10 k cycles.

The expected accelerated loss of capacity in summer, as well as additional loss of capacity from fast charging, are both showing up IMO, with ~14% capacity loss on L2, and ~17% loss on DC.

If this loss of capacity is different from what you think you are seeing in your hot climate LEAFs, remember this appears to be actual loss of total capacity from discharge tests, not the available (?) battery capacity as reported by your LEAF's LBC, as displayed in dash capacity bars or app/gid meter readouts.
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edatoakrun
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Re: INL L2 vs DC initial capacity test results after 10k mil

Fri Dec 06, 2013 11:08 am

40,000 mile capacity test results after ~ one year, as reported here:


http://avt.inl.gov/pdf/energystorage/DC ... et_40k.pdf" onclick="window.open(this.href);return false;

Looks like the L2 cars have lost ~22%, and the DC-charged LEAFs ~26%.

I repeat: I think someone in the Phoenix area really should try to get a look at these LEAFs.

Has anyone even attempted to see the capacity bars and/or check the gid/LEAF Spy reported battery capacity?

If the dash bars and gid counts show indicated losses of capacity differing significantly from these actual test results, this would be extremely valuable data, IMO.
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Stoaty
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Re: INL L2 vs DC initial capacity test results after 10k mil

Fri Dec 06, 2013 2:09 pm

edatoakrun wrote:40,000 mile capacity test results after ~ one year, as reported here:


http://avt.inl.gov/pdf/energystorage/DC ... et_40k.pdf" onclick="window.open(this.href);return false;

Looks like the L2 cars have lost ~22%, and the DC-charged LEAFs ~26%.
Interesting... the Battery Aging Model for Phoenix (4 miles per kwh, Leaf never parked in sun, assuming 2 months between manufacture and delivery) predicts 25.28% loss, which is pretty close. Looks like another validation of the Battery Aging Model to me. :D
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GRA
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Re: INL L2 vs DC initial capacity test results after 10k mil

Fri Dec 06, 2013 4:28 pm

Stoaty wrote:
edatoakrun wrote:40,000 mile capacity test results after ~ one year, as reported here:


http://avt.inl.gov/pdf/energystorage/DC ... et_40k.pdf" onclick="window.open(this.href);return false;

Looks like the L2 cars have lost ~22%, and the DC-charged LEAFs ~26%.
Interesting... the Battery Aging Model for Phoenix (4 miles per kwh, Leaf never parked in sun, assuming 2 months between manufacture and delivery) predicts 25.28% loss, which is pretty close. Looks like another validation of the Battery Aging Model to me. :D
Climate Arco - Idaho °C | °F
Jan Feb Mar Apr May Jun
Average high in °F: 29 35 46 58 67 77
Average low in °F: 5 10 21 29 37 43
Av. precipitation in inch: 0.83 1.06 0.87 0.75 1.34 0.91
Days with precipitation: - - - - - -
Hours of sunshine: - - - - - -
Jul Aug Sep Oct Nov Dec
Average high in °F: 85 83 74 61 42 30
Average low in °F: 48 47 38 29 18 6
Av. precipitation in inch: 0.83 0.79 0.71 0.63 0.79 0.83
Days with precipitation: - - - - - -
Hours of sunshine: - - - - - -

vs.

Climate Phoenix - Arizona °C | °F
Jan Feb Mar Apr May Jun
Average high in °F: 65 69 74 83 92 102
Average low in °F: 43 47 51 58 66 75
Av. precipitation in inch: 0.83 0.79 1.06 0.24 0.16 0.08
Days with precipitation: 4 4 3 2 1 1
Hours of sunshine: 248 244 314 346 404 404
Jul Aug Sep Oct Nov Dec
Average high in °F: 104 102 97 86 73 65
Average low in °F: 81 80 74 63 50 44
Av. precipitation in inch: 0.98 0.94 0.75 0.79 0.75 0.91
Days with precipitation: 4 5 3 3 2 4
Hours of sunshine: 377 351 334 307 267 236
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DaveEV
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Re: INL L2 vs DC initial capacity test results after 10k mil

Fri Dec 06, 2013 9:00 pm

edatoakrun wrote:Looks like the L2 cars have lost ~22%, and the DC-charged LEAFs ~26%.
Looks like the QC cars are holding up very well compared to the L2 cars. At 22%+ capacity loss these cars must be down between 2-3 capacity bars. It certainly feeds the belief that one should not worry about using QC when needed as long as it isn't over-used.
edatoakrun wrote:If the dash bars and gid counts show indicated losses of capacity differing significantly from these actual test results, this would be extremely valuable data, IMO.
Agreed.
Stoaty wrote:Interesting... the Battery Aging Model for Phoenix (4 miles per kwh, Leaf never parked in sun, assuming 2 months between manufacture and delivery) predicts 25.28% loss, which is pretty close. Looks like another validation of the Battery Aging Model to me. :D
Yeah, not bad.

I find it interesting how little capacity was lost between 10-20k miles. Were those miles purely put on during the winter months? The miles between 20-40k were a LOT harder on the batteries than the miles between 0-20k. At the 20k mark all cars were down about 2kWh, but at the 40k mark, cars are down 5-6 kWh - 2-3 times more capacity loss!

The L2 cars are losing about 1.31 kWh every 10k miles while the QC cars are losing about 1.47 kWh every 10 miles, or about 12% faster. After 40k miles, the QC cars hold about 0.7 kWh less energy than the L2 cars.

Stoaty
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Re: INL L2 vs DC initial capacity test results after 10k mil

Fri Dec 06, 2013 9:31 pm

GRA wrote: Climate Arco - Idaho °C | °F
Jan Feb Mar Apr May Jun
Average high in °F: 29 35 46 58 67 77
Average low in °F: 5 10 21 29 37 43

vs.

Climate Phoenix - Arizona °C | °F
Jan Feb Mar Apr May Jun
Average high in °F: 65 69 74 83 92 102
Average low in °F: 43 47 51 58 66 75
Not sure why you are bringing this up. The road testing was done in Phoenix. See page 16:

http://www4.eere.energy.gov/vehiclesand ... 2013_o.pdf" onclick="window.open(this.href);return false;
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