Collecting data:Off-the-wall power for turtle to 100% charge

edatoakrun said:

Couldn't much (or all?) of that discrepancy be explained (as IIRC, Phil has stated) by his efficiency results being only for a single point in time and when his battery was at single percentage of charge capacity, and prior to the charge taper at the end of the L2, (when the slower charge rate reduces the efficiency significantly) while NREL is the average efficiency over the entire charge?

Click to expand...

Yes, that's precisely the difference between power efficiency and energy efficiency. They can be only be used interchangeably if the power efficiency does not change over the range of operating conditions seen in the energy efficiency calculations, which is obviously not the case here.

While I *expect* L1 to match more closely than L2 (because I see NO taper on L1), I'm still surprised by the amount of discrepancy seen in the L2 results. That gives me pause to use the L1 power efficiency numbers for L1 energy efficiency. Note that for a charge from empty to full the voltage of the battery changes quite a bit. This also affects charging efficiency.

RegGuheert said:

....While I *expect* L1 to match more closely than L2 (because I see NO taper on L1), I'm still surprised by the amount of discrepancy seen in the L2 results. That gives me pause to use the L1 power efficiency numbers for L1 energy efficiency.

Click to expand...

Well, if you don't like the way I calculated L1 efficiency, and the ~75.5% efficiency results I got, do you have a better suggestion?

I can only state, that both my VLBW to 80% charges (with no taper, probably) as observed in charge time, and now my L1 charges as metered and measured in time (I saw virtually no taper in L1 on either of my tests, either, BTW) seem to be largely consistent when adjusted for battery temperature, but both also indicate large discrepancies between reported kWh use and the metered/timed recharges, and this discrepancy seemed to be even larger last Summer, than that I'm seeing this winter.

Which to me, sounds like I may be viewing Wh/gid variability, as expressed in my LEAFs kWh use reports.

edatoakrun said:

Well, if you don't like the way I calculated L1 efficiency, and the ~75.5% efficiency results I got, do you have a better suggestion?

Click to expand...

Well, I did give a *different* approach. I cannot say it is better, but it passes the reasonableness test for both your data and mine. The L1 efficiency numbers do not look reasonable with my data, as you have previously pointed out.

edatoakrun said:

I can only state, that both my VLBW to 80% charges (with no taper, probably) as observed in charge time, and now my L1 charges as metered and measured in time (I saw virtually no taper in L1 on either of my tests, either, BTW) seem to be largely consistent when adjusted for battery temperature,...

Click to expand...

Mine, too.

edatoakrun said:

...but both also indicate large discrepancies between reported kWh use and the metered/timed recharges, and this discrepancy seemed to be even larger last Summer, than that I'm seeing this winter.

Click to expand...

I'm with you in trying to see how much the GIDs move around! But it's really hard to draw conclusions without calibrated measurements and neither of us have calibrated meters. Since our charge measurements seem to track well with recharges, we might be able to look for hot versus cold *changes* in GID values, but I think we have little hope of pinning down the absolute value of a GID. But you seem to be seeing changes in the GID values.

Unfortunately, as you know, my Carwings data only got fixed at the end of August and I didn't start saving the Energy Rate Simulation data until December, so I don't have any stored hot-weather data in Carwings to go with my other charges. Let me see if the data is here on the forum...

edatoakrun said:

Which to me, sounds like I may be viewing gid W/h variability, as expressed in my LEAFs kWh use reports.

Click to expand...

Perhaps you mean GID Wh variability? Yes, I think that is an issue. It would be great to pin down at least how much it varies.

="RegGuheert"... But you seem to be seeing changes in the GID values...

Perhaps you mean GID Wh variability?...

Click to expand...

Actually, I meant to say Wh/gid variability, and edited my earlier post to correct the error.

I didn't mean to imply I had seen changes in Wh/gid values. My LEAF has never had a gid reading (yes, I'm curious...).

I was pointing out my observations of kWh use report variability, both seasonal and in absolute from "new" (five months and ~ 3,300 miles form new, in my case) seem similar to the pattern shown in gid reports, and the over-estimation of capacity loss both gids and capacity bars seem to produce in range tests, in hot (and maybe warm?) climate LEAFs.

I think it would be very useful for those using gid/soc meters to see if their estimates of Wh/gid closely match variations in Wh/(reported) kW, but to the best of my knowledge, very few observations on this subject have been posted.

edatoakrun wrote:
Well, if you don't like the way I calculated L1 efficiency, and the ~75.5% efficiency results I got, do you have a better suggestion?

Click to expand...

="RegGuheert"

Well, I did give a *different* approach. I cannot say it is better, but it passes the reasonableness test for both your data and mine. The L1 efficiency numbers do not look reasonable with my data, as you have previously pointed out.

Click to expand...

="RegGuheert"
...For reference, NREL got the following efficiency numbers using L2: 25.414kWh from wall and 21.381 from the battery, for an efficiency of 84%. If I "L2-ise" your results by subtracting 10.2 hours * 300 watts =3.06 kWh from your charge, I get (97.4mi/6.2)/18.95 kWh = 82.9% (CW) or (97.4mi/6.0)/18.95 kWh = 85.6%. Those look to be pretty much in the ballpark to me, particularly the Carwings one...

Click to expand...

I just don't know quite how to interpret your "L2-ise" results you posted previously, to get an L1 efficiency rate.

BTW, did you notice that this more recent study from Argonne National Laboratory, using different methodology, got 82.7% L2 efficiency?

http://www.transportation.anl.gov/D3/data/2012_nissan_leaf/AVTALeaftestinganalysis_Major%20summary101212.pdf" onclick="window.open(this.href);return false;

Charging efficiency drops quite a bit as the charge tapers, and even more so if there is balancing activity. This is how different cars can exhibit differing efficiency numbers. Balancing is a bank of resistors that are connected to each cell pair on demand to "waste" power and thus take some energy out of the stronger pairs.

Most of my measurements are below the 80% SoC point before tapering/balancing occurs.

Also note that the EVSE's Pilot signal regulates amperage, so on lower charge rates line voltage variance has a big effect on max charge power available. (120v X 12a = 1.44kW whereas if you lose 10v you only get 1.32kW)

-Phil

Thanks, Phil!

Ingineer said:

Charging efficiency drops quite a bit as the charge tapers, and even more so if there is balancing activity. This is how different cars can exhibit differing efficiency numbers. Balancing is a bank of resistors that are connected to each cell pair on demand to "waste" power and thus take some energy out of the stronger pairs.

Click to expand...

Agreed that balancing certainly affects overall system efficiency. But note that we observe NO taper in power with our L1 charging and that balancing does not affect the efficiency calculation of energy delivered to the battery pack divided by wall energy.

But balancing certainly DOES impact how much energy is consumed between one charge and another and between different cars. This seems to be particularly true at L1 rates since balancing is more effective when the charging is slower. I think the best we can do to minimize the effects of balancing is to charge to 100% a few times before we make our measurements to reduce the amount of balancing occurring.

Ingineer said:

Most of my measurements are below the 80% SoC point before tapering/balancing occurs.

Click to expand...

True, but while tapering is certainly part of the discrepancy with the NREL data I mentioned, balancing only affects the result of into-the-pack efficiencies in the fact that it affects how long the charge continues at the tapered power level.

Ingineer said:

Also note that the EVSE's Pilot signal regulates amperage, so on lower charge rates line voltage variance has a big effect on max charge power available. (120v X 12a = 1.44kW whereas if you lose 10v you only get 1.32kW)

Click to expand...

Understood. Can you comment on the accuracy of the EVSE current limit? For instance, you have measured 12.75A from your EVSE at L1 with a calibrated instrument. I measure even more current, although my instrument is not calibrated. How much variation do you see in the L1 current limit setting of these devices? TIA!

Another ~VLBW to "80%" timed charge result to post.

Following my 4/2/13 range test, it took ~4 hours and 14 minutes to recharge, after a reported 15.7 kWh use.

This compares with:

..16 amp 240v recharge (following the 9/8/12 range test)....took 4 hours and 16 minutes to reach 80% (and another one hour and 11 minutes to reach “100%”) following this trip...(after a reported 16.7 kWh used).

This compares to a recharge time of ~4 hours 25 minutes to reach “80%” following my first range test, on 9/7/11, with a reported 18.7 kWh used from 100% to about the same capacity level, ~VLBW.

Click to expand...

http://www.mynissanleaf.com/viewtopic.php?f=31&t=9064&start=30" onclick="window.open(this.href);return false;

So, assuming a constant charge rate to "80%", and that "80%" is a constant percentage of total battery capacity, both of which seem to be largely accepted, I think this is further evidence that my LEAF's available battery capacity has not declined very significantly since 9/7/11, and the kWh use reports from CW, which are used to calculate both my dash and nav screen m/kWh, are probably significantly lower than actual, as is also my conclusion from the range tests results.

I expect that the lower capacity and lower charging efficiency of my ~50 f battery (as opposed to the ~75 F battery during the 2011 and 2012 Summer tests) both had some effects on the charge time after the 4/2/13 range test, so I think those results are not as definitive as those I'll be able to collect once the weather heats up to "summer" conditions.

Below is how Carwings has reported the total energy use from "100%" to ~VLBW on my warm climate LEAF two years from the factory and with ~16,000 miles on the odometer.

While the reported kWh use has dropped quite a bit, My LEAF has displayed no significant loss of range from my first test, to most recent, on range tests of 95-113 miles, when corrected for all test variables, including speed, temperature both when charging and when driving, and my own driving efficiency (as reflected in the regen kWh reported by CarWings).

Of course my battery has lost capacity in the last 18 months, it just not yet a large enough loss to show up clearly in a range test, and is, IMO, nearly certainly far less than the kWh use results below, showing capacity loss approaching 15% just over the last 18 months (when adjusted for battery temperature) would indicate:

All charges prior to testing were to “80%", battery allowed to return to ambient temperature, and then charged @ 16 A 240 V to “100%”, two to three hours before range/capacity test begins, and then left plugged into the EVSE until departure.

IMO The distance driven at the point where the battery temp bars increased, when that has occurred, is useful data as to the relative battery temp and temperature the (temperature variable) battery capacity when the "100%" charge was completed.

9/7/11 18.7 kWh from "100%" to VLBW, 6 dash battery temp bars constant (as recalled later)

5/10 12 17.2 kWh, 5 to 6 temp bars ~mile 73

5/31/12 17.5 kWh, 5 to 6 temp bars ~mile 5

6/17/12 17.5 kWh, 6 temp bars constant

8/18/12 17.0 kWh, 6 temp bars constant

8/30/12 16.8 kWh, 6 temp bars constant

9/08/12 16.7 kWh, 5 to 6 temp bars ~mile 5

10/1/12 16.6 kWh, 6 temp bars constant

11/3/12 16.2 kwh, 4 to 5 temp bars ~mile 14

1/31 15.7 kWh, 4 to 5 temp bars ~mile 24

2/16/13 15.8 kWh, 4 to 5 temp bars ~mile 18

3/1/13 15.6 kWh, 4 to 5 temp bars ~mile 18

3/13/13 16.0 kWh, 5 bars temp constant

4/2/13 15.7 kWh, 4 to 5 temp bars at ~mile 1


I think it is nearly certain, that the LEAF "gauge error" that has shown up in premature battery capacity bar loss and Wh/gid error in other LEAFs is also displaying itself in the dash and nav screen m/kWh, and also in the (more accurate) CarWings kWh use reports, from my LEAF, as I have posted above.

IMO, any LEAFer who can learn to use CarWings, may see the same sort of results I have, and also be able to largely differentiate any range loss due to real battery capacity loss, from their LEAF's questionable kWh use reports, as I believe I have been able to do.

Click to expand...

RegGuheert on July 11 said:

Recharging from VLBW to 100%
Wall energy, L1, VLBW - 100%: 27.17 kWh
Time, L1, VLBW - 100%: 14.75 hours

I can only estimate L2 equivalent energy, but my estimate is certainly fraught with errors. To do this, I will assume L2 charging would have finished in 1/3 the time, or about 5 hours. During the additional 10 hours, I estimate 300W of power consumption by the LEAF for pumps, etc., for a total extra waste of about 3kWh. That gives:

Wall energy, L2 estimated: VLBW - 100%: ~24 kWh

Click to expand...

RegGuheert on October 20 said:

I did another recharge today from VLBW to 100% using L1. Ambient temperature was about 70F at the end of the charge. Here are the numbers:

Recharging from VLBW to 100%
Wall energy, L1, VLBW - 100%: 25.83 kWh
Time, L1, VLBW - 100%: 16.5 hours

I can only estimate L2 equivalent energy, but my estimate is certainly fraught with errors. To do this, I will assume L2 charging would have finished in 1/3 the time, or about 5.5 hours. During the additional 11 hours, I estimate 300W of power consumption by the LEAF for pumps, etc., for a total extra waste of about 3.3kWh. That gives:

Wall energy, L2 estimated: VLBW - 100%: ~22.5 kWh

ETA: Odometer reading for this charge: 5668 miles

Click to expand...

RegGuheert on March 2 said:

I did another recharge today from nearly VLBW to 100% using L1. While we didn't see VLBW, we were probably pretty close since we had driven about 3 miles with "5" shown on the GOM and about 2 miles with "4" shown on the GOM. The dash was only predicting 15.0 hours for a full recharge using L1, which seemed very low to me, so I decided to perform a test. Ambient temperature was about 35F at the end of the charge. Here are the numbers:

Recharging from VLBW to 100%
Wall energy, L1, just before VLBW - 100%: 24.74 kWh
Time, L1, just before VLBW - 100%: 16.0 hours

I can only estimate L2 equivalent energy, but my estimate is certainly fraught with errors. To do this, I will assume L2 charging would have finished in 1/3 the time, or about 5.3 hours. During the additional 10.7 hours, I estimate 300W of power consumption by the LEAF for pumps, etc., for a total extra waste of about 3.21kWh. That gives:

Wall energy, L2 estimated: just before VLBW - 100%: ~21.5 kWh

This result is about 4.5% less than the previous result at 70F, but the car wasn't quite to VLBW, so the comparative reduction is some unknown amount less than 4.5%.

Odometer reading for this charge: 9038 miles

Click to expand...

I did a recharge yesterday from 2 miles past LBW to 100% using L1. Those last two miles of the drive used very little energy. I probably traveled those two miles at 20 MPH average and power was nearly constant around 2 kW so I probably was about 200 Wh past LBW. That means I was around 45 GIDs. CarWings was only predicting 14.0 hours for a full recharge using L1. Ambient temperature was about 70F at the beginning of the charge and 80F at the end of the charge. Here are the numbers:

Recharging from ~LBW to 100%
Wall energy, L1, ~LBW - 100%: 23.4 kWh
Time, L1, ~LBW - 100%: 14.25 hours

I can only estimate L2 equivalent energy. To do this, I will assume L2 charging would have finished in 1/3 the time, or about 4.75 hours. During the additional 9.5 hours, I estimate 300W of power consumption by the LEAF for pumps, etc., for a total extra waste of about 2.85 kWh. That gives:

Wall energy, L2 estimated: ~LBW - 100%: ~20.5 kWh

There was clearly significant balancing going on at the very end of the charge as the power level rose by about 100W.

Odometer reading for this charge: 9835 miles

Regarding the drive that I took, it was ~70F on all three legs of the trip (even the last leg at 11:00 PM!). 78.6 miles at 5.1 mi/kWh on the dash. I don't have the CarWings report, yet, but I'll calculate the energy used to be 15.4 kWh. I will update if CarWings comes in different. If I really only consumed 200 Wh after LBW, then I'll put this at 15.2 kWh from full to LBW.

(Interestingly, the GOM read 9 during the last 4 miles of the drive! It dropped to 8 in our garage just before I turned off the car. As such, I really don't think we were very close to VLBW.)

L1 recharge energy efficiency: 15.4 kWh/23.4 kWh=66%
L2 recharge estimated energy efficiency: 15.4 kWh/20.5 kWh= 75%

Those numbers seem low, but the power levels rose quite a bit at the end. It could be due to significant balancing, but I suppose it could also be the meter. Let me see if I can think of a good way to test my meter.

Charged from Low Battery to 100%.
Blink (L2) energy - 17.5kWh, time - 4 hrs 45 min
SDG&E separate EV meter - 18 kWh
Ambient temp 58 degrees

2011 LEAF, Build Date: 2/11, Delivery Date: 20 Apr 2011, Leaf Number: 0984, Miles: 4,542 (drive much? )
Garaged, Location: San Diego County east of El Cajon, elevation 880 ft
DCFC only one time, never parked in noon day sun
No GID meter - on 4/20/13 garygid measured battery with ELM327 Bluetooth OBDII adapter and found battery degradation of about 10%

edited air temp

Charged from 5 miles past Low Battery Warning to 100%.
Nissan EVSE (modified) charging at L1 energy - 20.51kWh, time - 15 hours +/- 10 min
Measured with Kill-A-Watt
Ambient temp 65 degrees

[Mfg 8/2011][Purch 6/26/2012][6200 miles][12 Bars, 89+% CAP][4.5/kWh][80% L1]
Never DCFC
No GID meter - on 4/26/13 garygTX measured battery with ELM327 Bluetooth OBDII adapter using Turbo3's app currently in development and found battery degradation of about 10-11%

LBW at 91.9 miles
5.7 miles/kWh (Dash)
100.4 miles on the odometer
Recharge according to L2 Blink home charger 21.86 kWh
Temperature in garage was around 55 F

VLBW (23 gid) to 80%, 4h4m, 15.23 kWh

Didn't charge from 80% to 100% this time, but the last 3 80-100% charges have been in the range of 3.6-4.0 kWh.

Update on the recharge time results for my LEAF, now at ~20,000 miles, 26 months from production, and now under “85% capacity” as shown by the LEAF app:

Following 9/7/11 range/capacity test, to just past the VLBW, ~4 hours 25 minutes of recharge to reach “80%”.

Following the 9/8/12 range test ~4 hours and 16 minutes to reach 80% , and another one hour and 11 minutes to stop charging at “100%, 5 hours and 27 minutes total .

Following my 4/2/13 range test, it took ~4 hours and 14 minutes to “80%” (at considerably lower battery temperature).

Following 6/2/13/13 range test ~4 hours and 19 minutes to “80%”

Following 6/30/13 range test, ~4 hours and 18 minutes to “80%”.

Following 7/7/13 range test ~4 hours and 19 minutes to “80%”, and another one hour five minutes to stop charging at “100%”, 5 hours and 24 minutes total.

IMO, these recharge times from ~VLBW to “80%” seem consistent with my range tests, which have shown no significantly large losses of available battery capacity over the last ~22 months.


In addition to the very useful m/kWh at constant speed results for 2011 Nissan Leaf – VIN 0356, the total recharge times and kWh accepted are reported at:

Advanced Vehicle Testing – Baseline Testing Results

http://avt.inel.gov/pdf/fsev/fact2011nissanleaf.pdf" onclick="window.open(this.href);return false;

http://www.mynissanleaf.com/viewtopic.php?f=31&t=13265" onclick="window.open(this.href);return false;

I think considering the total charge times from ~turtle to "100%" may also be very useful, as the recharge times correspond so closely to the kWh recharge capacities for 0356.

It looks to me like the taper charge period may be so consistent as to allow useful comparison of capacity by measuring time, which is much easier to do accurately than measuring kWh from the wall, at least as the inconsistent reports of metered results on this thread seem to suggest.

If comparing total charge time is valid, then My LEAF may have close to the same average available capacity that 0306 had when it was tested, though the multiple variables and the variation in LEAF 0356’s measured recharge capacity in kWh (the three recharges varying between 18.1 and 18.6 kWh) gives you an idea of the limited precision of any available battery capacity measurement.

Unless the charge from “turtle” to VLBW is at lower kW (anyone checked that?) it may reasonable to add ~25 minutes to my total charge times to account for the ~1.5 kWh below VLBW capacity that I did not use in any of my range tests, to extrapolate a charge time for a SOC range equivalent to that tested for 0356.

Compare my 5:27 total recharge time from 9/8/12, and the 5:24 total time from 7/7/13 minute recharge, add 25 minutes, then you can compare an extrapolated average time of ~ 5:51.

Adjust my times by less than 1% to reflect my slightly lower voltage (~238 V, as best as I can tell) then you get an adjusted time of ~5 hours and 48 minutes.

Very close to LEAF 0356’s 5:37, 5:45, and 5:52 recharge times from “low turtle” to “100% shown in the tests of 0356, averaging ~5:45 (recharged at similar temperatures).

I didn't know this thread existed. I did a Turtle to 100%, measured by Kill-A-Watt, at the end of January:

http://www.mynissanleaf.com/viewtopic.php?f=27&t=11303&start=84" onclick="window.open(this.href);return false;

22.62kWh taken from the wall, with charging from Turtle taking 15h58m (19 hours indicated on the dash).

mwalsh said:

I didn't know this thread existed. I did a Turtle to 100%, measured by Kill-A-Watt, at the end of January:

http://www.mynissanleaf.com/viewtopic.php?f=27&t=11303&start=84" onclick="window.open(this.href);return false;

22.62kWh taken from the wall, with charging from Turtle taking 15h58m (19 hours indicated on the dash).

Click to expand...

~23 minutes longer than my last Winter L1 charge time.

But it would seem an anomaly that your Kill-A-Watt said you got only 0.62 kWh more than I did, for your "turtle" to ~VLBW capacity, rather than the ~1.5 additional kWh I'd expect.

From p 19 of this thread:

...for comparison:

Following 97.4 mile range test on 2/16/13, starting Odometer ~15,450 miles, where I got CW/nav screen report of of 15.8 kWh use from “100” to ~the VLBW, dash indicated “15 hours” recharge time to “80%”. test began with 4 temp bars, and went to 5 ~18 miles into the test, where it stayed to the end.

...Finished charge from “80%“ to "100%" 3 h 10 m (total charge time 15 h 35 min) 22.01 kWh total, showing 4 temp bars and at ~ 45 f ambient ...

Click to expand...

Perhaps due to my (colder?) battery having one or all:

Temporarily lower capacity, higher resistance, or a longer period of tapered charge?

Another result since my 7/22 post above.

edatoakrun said:

Update on the recharge time results for my LEAF, now at ~20,000 miles, 26 months from production, and now under “85% capacity” as shown by the LEAF app:

Following 9/7/11 range/capacity test, to just past the VLBW, ~4 hours 25 minutes of recharge to reach “80%”.

Following the 9/8/12 range test ~4 hours and 16 minutes to reach 80% , and another one hour and 11 minutes to stop charging at “100%, 5 hours and 27 minutes total .

Following my 4/2/13 range test, it took ~4 hours and 14 minutes to “80%” (at considerably lower battery temperature).

Following 6/2/13/13 range test ~4 hours and 19 minutes to “80%”

Following 6/30/13 range test, ~4 hours and 18 minutes to “80%”.

Following 7/7/13 range test ~4 hours and 19 minutes to “80%”, and another one hour five minutes to stop charging at “100%”, 5 hours and 24 minutes total.

Following 8/4/13 range test ~4 hours and 16 minutes to “80%”, and another one hour four minutes to stop charging at “100%”, 5 hours and 20 minutes total.


IMO, these recharge times from ~VLBW to “80%” seem consistent with my range tests, which have shown no significantly large losses of available battery capacity over the last ~22 months.


In addition to the very useful m/kWh at constant speed results for 2011 Nissan Leaf – VIN 0356, the total recharge times and kWh accepted are reported at:

Advanced Vehicle Testing – Baseline Testing Results

http://avt.inel.gov/pdf/fsev/fact2011nissanleaf.pdf" onclick="window.open(this.href);return false;

http://www.mynissanleaf.com/viewtopic.php?f=31&t=13265" onclick="window.open(this.href);return false;

I think considering the total charge times from ~turtle to "100%" may also be very useful, as the recharge times correspond so closely to the kWh recharge capacities for 0356.

It looks to me like the taper charge period may be so consistent as to allow useful comparison of capacity by measuring time, which is much easier to do accurately than measuring kWh from the wall, at least as the inconsistent reports of metered results on this thread seem to suggest...

Unless the charge from “turtle” to VLBW is at lower kW (anyone checked that?) it may reasonable to add ~25 minutes to my total charge times to account for the ~1.5 kWh below VLBW capacity that I did not use in any of my range tests, to extrapolate a charge time for a SOC range equivalent to that tested for 0356.

Compare my 5:27 total recharge time from 9/8/12, and the 5:24 total time from 7/7/13 minute recharge, add 25 minutes, then you can compare an extrapolated average time of ~ 5:51.

Adjust my times by less than 1% to reflect my slightly lower voltage (~238 V, as best as I can tell) then you get an adjusted time of ~5 hours and 48 minutes.

Very close to LEAF 0356’s 5:37, 5:45, and 5:52 recharge times from “low turtle” to “100% shown in the tests of 0356, averaging ~5:45 (recharged at similar temperatures).

Click to expand...

5/5/14-edit to remove erroneous comment on voltage adjustment

camasleaf said:

camasleaf said:

Just finished charging turtle to 100% on my new Leaf now at 430 miles. The Blink reported 24.9 kWh in 6.44 hours. I will try to turtle the older Leaf tomorrow.

Click to expand...

The older Leaf finished charging from turtle to 100%: 23.2 kWh in 6:14 hours. So after almost 23000 miles in 16 months the capacity dropped about 1.5 kWh or 7% (assumed 90% efficiency).

Click to expand...

Now the old Leaf at 34000 miles GID around 247, AHr=57.11, (87.06%) Hlth 74.17 from turtle to 100% Blink reported 22.1 kWh; The new Leaf close to 11000 miles still holds at 277 GID.

camasleaf said:

...Now the old Leaf at 34000 miles GID around 247, AHr=57.11, (87.06%) Hlth 74.17 from turtle to 100% Blink reported 22.1 kWh...

Click to expand...

Do you have the charge time?

edatoakrun said:

camasleaf said:

...Now the old Leaf at 34000 miles GID around 247, AHr=57.11, (87.06%) Hlth 74.17 from turtle to 100% Blink reported 22.1 kWh...

Click to expand...

Do you have the charge time?

Click to expand...

Charging time 6:05. Battery temp from around 66F at start to 70 at end.Cell voltage delta was 223 at turtle and around 22 mv at the end. I have a few leafspy screen captures.

Continuing from:

http://www.mynissanleaf.com/viewtopic.php?f=30&t=8802&start=6800" onclick="window.open(this.href);return false;

drees wrote:

Drained my car to turtle (5 GIDs) on a 80% charge (188 GIDs) driving 51.6 mi at 3.5 mi/kWh (About half surface streets, half freeway at ~70 mph). LBW came on a bit over 40 miles and VLBW came on around 48 miles. Pulled into garage with 12 GIDs and drained the rest using the heater/defroster on max. Turtle came on at 6 GIDs. Lowest cell-pair around 3.1V, average 3.3V, max 3.45V. Finishing battery temp around 90F, started the morning with the battery around 80F.

Charged to 80% immediately after that which took 4:18:35 drawing 16.157 kWh according to my Blink EVSE...

Click to expand...

Not trying to cast doubt on the reliability of any Blink device, but...

If you have 240 V, shouldn’t the EVSE pull ~16.55 kWh over that period of time?

Is your voltage lower than 240?

For that matter, anyone seen any variation from 16 A (L2) for a 2011-12 LEAF charger?

I've been wasting my time keeping time records, if it is not a constant.

drees wrote:

I didn't charge all the way to 100% as I wasn't planning on going anywhere soon this morning, but my last five 80-100% charges in the last 3 months ought to be good enough to take an average. Here they are in descending order from most recent to oldest:
1:08 3.567 kWh
1:00 3.268 kWh
1:04 3.116 kWh
1:10 3.683 kWh
1:00 3.300 kWh

Average time was 64 minutes, average energy 3.39 kWh.

So we can safely assume a full charge would have taken about 5h 22m and drawn 19.5 kWh.

We know that a new LEAF will pull about 24.5-25.0 kWh from the wall. Mine pulls less than 20 kWh.

In conclusion, my current Ah reading of 53.6 is 81% of a new LEAF's ~66 Ah. My energy used to charge is about 78-80% of what a new LEAF pulls from the wall to charge from turtle to 100%. If anything, the car is over-estimating capacity, not under.

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Were all the “80%” to “100%” sessions at ~the same high battery temperatures?

IMO, due to the imprecision of LBC instrumentation, the exact percentage of total battery capacity when the LBC determines every marked or set SOC (at least the ones I've seen, VLBW, LBW, "80%" and "100%") so the kWh accepted on any recharge between any two of these SOCs, as a percentage of total battery capacity, can probably vary significantly.

I believe this been shown, in my LEAF, by differences in both kWh charge accepted, and kWh discharge allowed, from VLBW to "100%" and back, even with near-identical battery temperatures when charging.

So I don't believe that you can reasonably expect to approximate capacity loss from any single charge session, or any single range test.

And trying to assemble a composite capacity with an average of previous sessions throws additional uncertainty into the question. You are, in effect, giving the LBC two chances to miscalculate the two charge-end SOCs, and while different LBC errors estimating "80%" and "100%" in two separate sessions could offset each other, they could also produce a higher cumulative error than you could get in a single charge event.

drees, I believe your LEAF has lost a significant amount of capacity, and mine has too.

As should be expected after ~3 years and ~27,000 miles.

I just think you are stretching to claim that your LBC's accuracy has been validated by what you have posted.

BTW, even if you can show that your:

drees wrote:

...own measurements of energy used to charge the car have directly correlated with the car's reported capacity loss...

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The part of your statement I found without support was:

drees wrote:

...own measurements of energy used to charge the car have directly correlated with the car's reported capacity loss and so has everyone else's...

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