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

[mwalsh]

Thanks - very interesting datapoint indeed. Looks like time is more a factor then miles/charge cycles since oyu are hanging right in there with all the other 1 year owners with >15000 miles.

Yes, sadly, I was thinking the same thing.

Me too. I now firmly believe that degradation began the first time these cars were charged in Yokosuka, maybe even the moment the packs were built. And it continued for every car at rates adjusted for regional temperature - quicker and more apparently in Arizona; almost imperceptibly in mild climes like the PNW.

 

[DaveinOlyWA]

Mine took 25 kWh last time I fully killed (and pushed into the parking space) my LEAF, and charged from the wall. Since it's L1 and I didn't have authorization from the apartment management yet to run the cable, I broke it into two overnight sessions. I drove a bit the second day but got an equal charge from the L2 station at the dealership, came home with the same SOC I left with (but wasn't really concentrating on monitoring it as I would if I were doing it for this thread).

I got a VLB warning on my "100-mile club" trek back home last night, though, but since I had an appointment for a firmware update at Nissan this morning, they charged it at their service-area charging station to 100% while I slept in.

So, between the two sessions, my Kill-A-Watt meter showed 25 kWh between those two sessions. I just remember seeing that on the meter and thinking "geez, for a 24 kWh battery, that's pretty good efficiency!"

25 Kwh is about right on L1. the slower you charge, the lower the efficiency of power from the wall to the battery due to overhead caused by the cooling system for the inverter, charger and AC/DC converter.

my off the cuff measurements (also used Kill a watt meter) as compared to the miles/kwh meter i got an average of 75-76% efficieny so if you put in 25 Kwh, you charged up about 19 Kwh

 

[WetEV]

Me too. I now firmly believe that degradation began the first time these cars were charged in Yokosuka, maybe even the moment the packs were built. And it continued for every car at rates adjusted for regional temperature - quicker and more apparently in Arizona; almost imperceptibly in mild climes like the PNW.

Yes. Life with a BEV.

This is perhaps why Nissan has never published a new battery capacity specification. Suppose all Leafs have 21kWh +-0.01% battery packs installed. Consider two Leafs. One is taken to a dealership down the street from the factory and turned over to the new owner the same day. The other is shipped to other side of the world, and sits on a dealer's lot for months (hopefully at 40% to 60% SOC). While I don't know exactly what the capacity in the second case will be, I'm very sure it will be measurably less than the first. And both will be "New Leafs". And the "New Leaf Range" will be different as well.

Nissan needs to put a price on a replacement battery pack. While I hope not to need one for many years here in the PNW, I want to know. People in warmer places need to know.

For almost everyone, the price of the battery degradation is larger than the price of the electricity.

 

[FalconFour]

25 Kwh is about right on L1. the slower you charge, the lower the efficiency of power from the wall to the battery due to overhead caused by the cooling system for the inverter, charger and AC/DC converter.

my off the cuff measurements (also used Kill a watt meter) as compared to the miles/kwh meter i got an average of 75-76% efficieny so if you put in 25 Kwh, you charged up about 19 Kwh

If there's going to be any significance to my measurement there, e.g. stored LEAF with only calendar/environment losses and no cycle losses, I'll have to do a more scientific test to be sure. Since I did drive halfway through the charge, it wasn't a test designed to kill the battery and test it... it was just a long drive on a weekend and came home completely dead :lol:

In other words, don't put my figure there into a table quite yet if it's going to skew results... because it's almost entirely certain there's about an 8% margin of error due to the driving/charging at the L2 dealership station! :lol:

 

[JimSouCal]

Newbie question: if one is using the measured amount of energy going into the depleted battery from the wall to charge completion, wouldn't the internal resistance of the battery possibly vary from unit to unit, and the heat energy would produced in charging that would not be stored as potential charge energy to do work, and the presumed results vary in actual performance measured at the drive wheel? Not saying that is the case, but I do wonder?

Anyway, I have a killawatt meter and was thinking of trying this when it seems convenient to be without the car for a day or so.

 

[DaveinOlyWA]

Newbie question: if one is using the measured amount of energy going into the depleted battery from the wall to charge completion, wouldn't the internal resistance of the battery possibly vary from unit to unit, and the heat energy would produced in charging that would not be stored as potential charge energy to do work, and the presumed results vary in actual performance measured at the drive wheel? Not saying that is the case, but I do wonder?

Anyway, I have a killawatt meter and was thinking of trying this when it seems convenient to be without the car for a day or so.

definitely since no two "anythings" are identical but the manufacturing process should be controlled enough that differences from pack to pack should be minor.

all the more reason that baseline be recorded when the car is new. something i never even thought to do.

 

[Devin]

I just ran the car down to turtle for the first time and charged back up to 100% (no timer). I used my AeroVironment L2 charger and my LADWP meter to measure. I measured 22kWh (3583kWh meter start, 3605 meter end).

Ambient temperature was a little over 50 degrees overnight and my car was just in to turtle. I pulled into garage after VLBW and ran the heater until turtle displayed. About 15 minutes before I reached turtle the battery temperature went from 5 temp bars to 6 temp bars. When I woke up this morning the battery temperature displayed 5 temp bars.

My car has 16,501 miles on it and shows all 12 capacity bars available.

 

[DaveEV]

I just ran the car down to turtle for the first time and charged back up to 100% (no timer). I used my AeroVironment L2 charger and my LADWP meter to measure. I measured 22kWh (3583kWh meter start, 3605 meter end).

My car has 16,501 miles on it and shows all 12 capacity bars available.

About 10% down from new, or perfectly normal for a Los Angeles car of that age and mileage.

 

[bowthom]

Hello,
I've never ran my Leaf "E"mpty so the best data I have is LBW to 80% = 16.791 kWh measured by the blink.
Batt temp = 6 bars
Ambient temp = 65*

 

[mkjayakumar]

Here is a thought process to avoid aging before the car is sold and delivered the customer. The cars and the battery to be shipped separately from the factory. The battery is to be kept in cold storage at 50F with 50% SOC. Once the sale is done, the battery is then yanked out of the storage and installed into the car.

regards
Jay

 

[Volusiano]

I don't have any special meter to measure energy consumption of a charge. Can I use the Blink's reading to make measurement? Exactly how should I do this? Record the energy value in the Stats page before and after charging and take the difference?

How accurate is the Blink's measurement, and do you need to factor in any energy inefficiency loss to the end result? Thanks.

 

[vegastar]

Hello,
I've never ran my Leaf "E"mpty so the best data I have is LBW to 80% = 16.791 kWh measured by the blink.
Batt temp = 6 bars
Ambient temp = 65*

That is a very good result. My last charge below LBW was from 39 gids (LBW appears at 49 gids, VLBW at 24 gids) to 215 gids (80% charge), or 359.75V to 385.75V, and I used 13.81 kW.h from the wall.

You charge was after just entering LBW, or well into LBW and aproaching VLBW?

 

[DaveEV]

Hello,
I've never ran my Leaf "E"mpty so the best data I have is LBW to 80% = 16.791 kWh measured by the blink.
Batt temp = 6 bars
Ambient temp = 65*

That is a very good result. My last charge below LBW was from 39 gids (LBW appears at 49 gids, VLBW at 24 gids) to 215 gids (80% charge), or 359.75V to 385.75V, and I used 13.81 kW.h from the wall.

No kidding I'd say that's a good result. My last LBW (got it after pulling into the garage) to 80% charge a couple weeks ago was only 12.416 kWh measured by the Blink. About 16 months old and 12.5k miles. For me to get 16 kWh on a 80% charge, I had to go all the way down to VLBW - in July I did that (0.8 mi past VLBW to 80%) and got 16.259 kWh.

I don't have any special meter to measure energy consumption of a charge. Can I use the Blink's reading to make measurement? Exactly how should I do this? Record the energy value in the Stats page before and after charging and take the difference?

How accurate is the Blink's measurement, and do you need to factor in any energy inefficiency loss to the end result? Thanks.

I don't think anyone has independently verified the Blink's accuracy, but it seems to be OK. Use the blinknetwork.com website after your charge to pull the data down. Doesn't hurt to also record the time spent charging, too.

 

[phxsmiley]

With the Blink unit, you can go online to blinknetwork.com, log in, select your Blink unit, and you can see the power measured during a recent charge. I did this to do a turtle-to-100% power measurement and the results seem accurate, when compared to using a Kill-A-Watt with a modified L1 Rev2 EVSE. I did the two measurements a day apart from each other.

You have to adjust for efficiency, depending if you are using L1 or L2. Phil measured the efficiency of the Rev2 Modified EVSE at 120V to be 78%; Others have estimated their L2 EVSEs to be around 88%-90% efficiency. I gleaned both of those facts from posts here.

TickTock told me that Nissan seems to use 21kWh as the available capacity of a new, full pack. So, that gives you the denominator. My last measurement was about 17.5kWh, giving me about 83% capacity.

 

[DaveEV]

You have to adjust for efficiency, depending if you are using L1 or L2. Phil measured the efficiency of the Rev2 Modified EVSE at 120V to be 78%; Others have estimated their L2 EVSEs to be around 88%-90% efficiency.

L1 is ~78%. L2 16A is ~87%. L2 12A is probably a couple percent less.

TickTock told me that Nissan seems to use 21kWh as the available capacity of a new, full pack.

NREL verified that number along with L2 charging efficiency: NREL LEAF Teardown and Detailed Testing.

 

[LEAFer]

So after our Folsom meetup yesterday I went to Turtle. I purposely did not charge at the meetup, planning on Turtleing it. I might as well post the trip data, then the re-charging data. I'll let the forum members decide what our battery degradation is.

Lost 
Bar#  at (miles)
12     5.0
11     ? (missed it)
10    16.0
 9     20.8
 8     28.4
 7     32.7 parked; at restart had lost the next bar.
 6     34.5
 5     44
 4     48
 3     52.8
 2     61.8  @63 LBW with "8" flashing"
 1     70.2 & VLBW

One mile past VLBW (@71.2) I parked at home. EE 4.5 miles/kWh, avg speed 30.6, time 2:19 (the car was left on several times while chatting with people), Odometer: 26,880. The car had charged overnight to 100% in 50-55F temps, and showing 5 TempBars in the morning and all day until about 10 miles from home in the afternoon around 3pm with 72F ambient. On the outbound I drove flat country roads at 55mph, then a 4 miles section of freeway at 63mph to Folsom. On the return 45mph for 4 miles, then 55mph for ~21 miles, then (with 7 miles left to go and 7 showing on the GOM) I chickened out and drove 40mph for 5 miles. It helped; I increased speed to 52mph to home.

Once parked at home I tried to reach Turtle via heater and A/C while watching "Estimated time to charge to 100%" : 240V 6:30 and 120V 18:00 !! It was a slow process. After 15 minutes I drove an extra mile at 15mph (still no Turtle or power loss). For an additional 10 minutes using full heat and alternating to full A/C the Est. times hit 120V 20:00 and 240V 7:00, but still no Turtle. Turned the car off and back on, and voilà, Turtle !

Plugged in at 15:51 with 6 TempBars, 243.5V 15.53A. After a full charge, per ChargePoint sometime before 21:46 had used 20.544 kWh (SMUD meter recorded 21kWh). The GOM showed 90miles, 12 bars and all 12 capacity bars. This morning checking ChargePoint, an additional 0.178kWh was delivered sometime between 00:06 and 00:21 (shortly after midnight). And the Carwings ChargeComplete notification was received at 00:14. And the GOM still shows 90 and 5 TBs this morning.

So ... how close to losing the 12th bar did we come before the weather dropped our daytime temps by 20 degrees about 10 days ago ? (Also note the GID test in signature below.)

Edit: So the summary: Turtle to 100% at L2: 20.722 kWh.

 

[DaveEV]

It sure looks like you're down 20% on capacity, even though your GID count only says 8%.

Using data from your gauges:

4.5 mi/kWh * 21 kWh = 94.5 mi.
Add 5 miles to your mileage reading to estimate miles to turtle:
75.2 mi / 4.5 mi/kWh = 16.7 kWh which is about 80% of new

Using wall data:

From the wall, a new LEAF will put in about 25.4 kWh from the wall.
20.544 / 25.4 = 81%

So the wall data and your gauge data is a near perfect match (certainly well within the margin of error). The question is why is your GID count so high?

Oh - and do you have all the firmware updates on your car? Getting LBW with 2 bars and VLBW with 1 bar doesn't seem right...

 

[DaveinOlyWA]

L2 from the wall can be up to 90% efficient so i would peg his degradation at 13%.

another thing to watch for if driving around trying to turtle is the power circles. you will lose about 5-6 of them before turtle so if concerned about making back home, watch for the power circles to disappear then head for home. its only a mile or so from first power circle disappearance to turtle

 

[DaveEV]

L2 from the wall can be up to 90% efficient so i would peg his degradation at 13%.

13% would indicate that a new car would only take 22 kWh from the wall when new - which is at least 10% down from every single turtle to 100% charge I've ever seen documented from the wall on a new car.

 

[DaveinOlyWA]

when the LEAF is new it has about 21 and a half kilowatt hours. so charging on l2 it 89 or 90 percent efficiency means it will take about 24 kilowatt hours