98.3 Miles in a new 2013, Very Odd Gid Behavior near Turtle

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Boomer23

Well-known member
Joined
May 23, 2010
Messages
3,561
Location
Orange County, CA
I just did a full range test in my new 2013 SL and achieved 98.3 miles at an average economy of 4.5 mi/kWh.

If we believe that the 4.5 mi/kWh on the dash is accurate, that reflects available energy in the pack of 21.84 kWh. I'll report on the energy required to recharge to 100% according to my TED monitor in the morning.

I drove most of the day in Drive, with B mode active (increased regen braking). My driving route for the day started with a couple of 5 mile freeway trips in varying speed traffic, with a max speed of about 60 mph. In between the freeway stints, I drove a few miles that included hills at moderate speeds. The rest of the day's driving was conservative suburban driving with some undulating hill sections.

I drove about 80 miles in the above manner, averaging 4.4 mi/kWh on the dash and then I decided to turn the day's drive into a range test. I had the original Gidmeter on.

LBW occurred as expected at 49 Gid, and VLBW at 25 Gid.

I decided to drive it down to about 10 Gid to avoid torturing the poor pack to Turtle. The Gid reading declined steadily to 10 and I stopped the car with the economy display still showing 4.4 mi/kWh and the odometer was at 90.4 miles. I figured that at 10 Gids, I might have one or two miles left before Turtle at 5 Gids. I took readings from the Gidmeter and the LEAF Battery App. I was surprised to notice that with the Gidmeter reading 10 Gids, the SOC% was 9.3%. The LB App also showed 9.3 %SOC, with a much different simulated Gid reading of 26 'Gids. (I realize that simulated Gids are different from true Gids and that the difference is greatest at low SOC, but this was ridiculous). The App said that I still had about 2.1 kWh in the pack and more than 3 miles left to drive at 4.0 mi/kWh. So I decided that with 9.3% SOC remaining, I really should drive down to Turtle to see what happened to the readings. So I turned the car back on and started driving in circles at about 35 mph, watching the Gid reading on the Gidmeter and waiting for Turtle to happen in a couple of miles.

Here's where things got very, very odd indeed.

I drove the car almost 8 more miles between 10 Gids and 5 Gids, ending at 98.3 miles total!!!! I've never seen or heard of this before. It was almost as if the car had a reserve to extend the range below 10 Gid.

The Gid count dropped slowly from 10 to 9 and then lower, but it stopped dropping at 7 Gids and just remained at that reading while I drove about three miles. The Gidmeter SOC% continued to slowly drop. Eventually, the Gid reading dropped to 6 Gid and remained there for more than a mile before dropping to 5 Gid, and finally Turtle appeared. I managed to get into my driveway, but couldn't make it up the short incline into the garage before the car went into Neutral. As I mentioned, the odometer now read 98.3 miles, the energy display was at 4.5 mi/kWh, the Gid display was 4, simulated 'Gids was at 3, and the SOC% was now 1.1% on the Gidmeter and the LB App. Voltage on the Gidmeter was 294 Volts.

I realize that I was hypermiling to an extent, driving at 30 to 35 mph and stopping at a couple of stop signs as I circled near my house, using up that 6 Gid. But there is no way in hell that 6 Gids would provide 7.9 miles of driving! I would expect a maximum of 2 miles, maybe 3 miles at the extreme.

I wonder if this is typical of a 2013 pack, some anomaly of my own quite new pack with only 336 miles on it, or what. I hate to torture my pack, but it would be interesting to see if a similar full range test would produce similar weird results below 10 Gids. EDIT: The LB App showed AH of 63.53 and CAP% of 95.89 at Turtle.
 
Great summary, thanks for posting that Boomer! This make much more sense now, I was really surpried to see the range and energy economy figures you posted earlier on Facebook knowing that the CAP reading was about 95%. This is indeed odd, and the closest thing I can think of was Randy's LEAF, which I piloted at the Phoenix range test last year. It travelled about 20 miles between the low and very low battery warning at 65 mph. That's more than twice the distance one could have reasonably expected, and I have never seen anything quite like this either. Assuming that each Gid was 80 Wh, as Ingineer told us, then 5 Gids should give you about 1.8 miles of range at 4.5 m/kWh (0.08 x 5 x 4.5). Your car travelled much farther, and as odd as it might sound, the only explanation I would have is that the battery controller software might be still learning and adjusting to your pack?
batteryproblemmnl
 
surfingslovak said:
Great summary, thanks for posting that Boomer! This make much more sense now, I was really surpried to see the range and energy economy figures you posted earlier on Facebook knowing that the CAP reading was about 95%. This is indeed odd, and the closest thing I can think of was Randy's LEAF, which I piloted at the Phoenix range test last year. It travelled about 20 miles between the low and very low battery warning at 65 mph. That's more than twice the distance one could have reasonably expected, and I have never seen anything quite like this either. Assuming that each Gid was 80 Wh, as Ingineer told us, then 5 Gids should give you about 1.8 miles of range at 4.5 m/kWh (0.08 x 5 x 4.5). Your car travelled much farther, and as odd as it might sound, the only explanation I would have is that the battery controller software might be still learning and adjusting to your pack?
batteryproblemmnl

We shall see, I guess. More data in the morning after TED records the charging energy back to full.

The one missing datum is the charging efficiency of the new 6 kW on board charger. I'm using a Nissan/Aerovironment EVSE on a 40 Amp breaker, and it uses 6.6 KW while charging. Does anyone yet know the charging efficiency with 240 Volts and the 6 kW charger?
 
Boomer23 said:
The one missing datum is the charging efficiency of the new 6 kW on board charger. I'm using a Nissan/Aerovironment EVSE on a 40 Amp breaker, and it uses 6.6 KW while charging. Does anyone yet know the charging efficiency with 240 Volts and the 6 kW charger?
I don't think anyone has instrumented it and published the results. I would assume around 87% efficient, same as the old car/charger.

Between the extended range your car had below VLBW and compared to the Ah reading, it sure seems that when the LBC thinks the battery has less capacity than it does, it triggers LBW sooner than it should.

At the very least, that's how the '11-12 cars with the latest firmware updates seem to confirm - battery capacity from turtle to 100% doesn't change before/after update, but range between 100%-LBW is expanded about 5-10%.

Will be very interesting to see your wall data. I don't know if anyone else has published wall data for 6 kW charging on a '13 LEAF.
 
How new is your SL? Maybe the BMS is still learning your charge/discharge profile and next time it will better predict the remaining capacity at low charge.
 
Boomer23 said:
I just did a full range test in my new 2013 SL and achieved 98.3 miles at an average economy of 4.5 mi/kWh.

If we believe that the 4.5 mi/kWh on the dash is accurate, that reflects available energy in the pack of 21.84 kWh...

Did you record the nav screen m/kWh?

Is the nav screen still showing a ~2.5% higher m/kWh value than the dash, as on all 2011-2012's?

="drees"
Boomer23 said:
The one missing datum is the charging efficiency of the new 6 kW on board charger. I'm using a Nissan/Aerovironment EVSE on a 40 Amp breaker, and it uses 6.6 KW while charging. Does anyone yet know the charging efficiency with 240 Volts and the 6 kW charger?
I don't think anyone has instrumented it and published the results. I would assume around 87% efficient, same as the old car/charger...

I think most testing has shown more like ~85% efficiency for the 3.3 kW full charge to 100%. Isn't ~87% reported for that portion of the charge at the full ~3.3 kW rate, excluding the less-efficient charging where rate tapers near the end?

These tests show a ~84.5% to ~86% range charging all the way to "100%"

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

edit-found the 85.3% average efficiency over 13 charge sessions from Argonne on p 21 here:

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

Shouldn't we expect the 2013 with the 6 kW charger to show significantly higher efficiency, due to the lower "overhead" added by the cooling system, due to both shorter charging time, and the fact that the cooling system now also (reportedly) regulated by the charge rate, for higher efficiency?

Isn't this increased charge efficiency also likely to be the reason for a significant fraction of the increase in EPA-rated "mpge", from 99 mpge for the 2012 LEAF, to 115 for the 2013?

http://www.fueleconomy.gov/feg/Find.do?action=sbs&id=33558" onclick="window.open(this.href);return false;
 
Re-charging data measured by TED is in: 25.3 kWh over night without an end timer.

Gid reading this morning was 276, the highest it's been.

Just for some history, Gid readings at 100% were:
263 when I picked up the car and it had finished charging without timers
267 on June 16
271 yesterday morning, June 20
276 today, after the Turtle event and full charge.

Also interesting and encouraging, AH this morning from the LB App was 63.71, up from 62.4 yesterday, and CAP% was up to 96.16 from 94.2 yesterday.

Here's a screen shot of the charging event last night from TED. The ramp-down and cycling at the end of the charge is much more pronounced with this battery than anything I ever saw with my 2011 car.

TED after first Turtle to full chg 6 21 13 size.jpg
Also, the cell pair chart on the LB App was mostly red this morning, indicating additional balancing going on.
ELM after full charge from Turtle 6 21 13.jpg
 
TickTock said:
How new is your SL? Maybe the BMS is still learning your charge/discharge profile and next time it will better predict the remaining capacity at low charge.

That's the kind of thing I'm hoping will happen. I was pretty alarmed to see that the AH of the new pack by the LB App was only 60.89 when I picked up the car, CAP of 91.91%. But these numbers have gotten better, with some fluctuations, in the week that I've been using the car. AH this morning of 63.71 and CAP of 96.16%.

To answer your question, I've had the car a week and it has only 336 miles on it.
 
edatoakrun said:
Did you record the nav screen m/kWh?

Is the nav screen still showing a ~2.5% higher m/kWh value than the dash, as on all 2011-2012's?

~~ snip~~

Shouldn't we expect the 2013 with the 6 kW charger to show significantly higher efficiency, due to the lower "overhead" added by the cooling system, due to both shorter charging time, and the fact that the cooling system now also (reportedly) regulated by the charge rate, for higher efficiency?

Interesting that you bring up the dash/nav screen mi/kWh displays. I've noticed that they are MUCH more likely to show the same reading on my 2013 car than on my 2011.
EDIT: And yes, the two readings were identical at the end of the day, 4.5 mi/kWh.

Regarding the charging efficiency, see my post above about wall charging energy this morning. We can make some rough estimate of charging efficiency, as long as we accept a calculated figure for usable kWh. If we believe the kWh capacity calculation from my dash reading, I used 21.84 kWh to drive 98.3 miles at 4.5 mi/kWh. If that figure is approximately right, and last night's re-charge took 25.3 kWh, then charging efficiency with my setup was 86%.
 
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