Degradation on Brand New 2015 SV

[apacheguy]

I did some testing tonight on my 2 week old 2015 SV and I'm not at all happy with the results. In short, I was sold a brand new 2015 that had already seen 1.4 kWh in degradation. I would be happy if the car were a year old and had 10,000 miles on it, but it doesn't. It has less than 500! IMO, this is unacceptable for a new car.

---The Data---

I connected the car at dead, 0, nada and decided to charge her up to 100% and measure the wall power.

Method: Chargepoint L2 @ 208 V 3 phase power
Avg ambient temp during charge: 65 F
Energy: 24.08 kwh
Time elapsed: 5:10:52

Weird. Can't get the image to show up. Basically, it's a graph of my charge session showing all the stats. [mod edit, fixed URL]

Car read 72 F once charge had completed showing 6 battery temp bars.

---The analysis---

I referenced Tony's post over here (http://www.mynissanleaf.com/viewtopic.php?t=16197)

Energy from the wall from dead to 100%: 25.414 kWh
Energy from the onboard charger to battery: 22.031 kWh (86.6% charger efficiency)
Energy from the battery during discharge: 21.381 kWh (our 21kWh useable at 70F)

http://www1.eere.energy.gov/vehiclesandfuels/pdfs/merit_review_2012/veh_sys_sim/vss030_lohsebusch_2012_o.pdf" onclick="window.open(this.href);return false;

http://www1.eere.energy.gov/vehiclesandfuels/pdfs/merit_review_2012/adv_power_electronics/ape006_burress_2012_p.pdf" onclick="window.open(this.href);return false;

L2 charge from dead should deliver 25.4 kWh. In my case it only delivered 24 kWh.

Quick side note: Does anyone know if the 86.6% charger efficiency accounts for auxilary overhead during charging (rumored to be 300 watts)? Sure hope so, otherwise I'm looking at another 1.5 kWh of degradation bringing the total to 2.9 kWh.

 

[jpadc]

I think you will find measuring wall voltage input to the car is NOT a reliable enough method to allow for conclusions about battery degeneration. Lots of factors (beyond just temperature) will effect charging efficiency, not to mention variability in the exact SOC the battery is at when shutdown occurs (which is never 0 dead nothing to protect it).

I'm sure if you have read through enough posts to find that one by Tony, you would have seen plenty of posts about LeafSpy. You really need that tool to get battery readings including number of Gids at full charge, Ahr and SOH readings to tell you reliable information about the health of your new battery. Once you get in, I'm sure you will find your Car's battery is in excellent shape. You also may note that the battery actually starts improving a little bit as its first put in regular service.

 

[aarond12]

You also may note that the battery actually starts improving a little bit as its first put in regular service.

Agreed. I noticed my battery improved notably after the first month of ownership (and a month of the previous owner who, I believe, only L1 charged it).

 

[DaveEV]

IMO 24kWh from the wall at 208/240V on a '13+ LEAF is completely normal for a couple reasons.

1. The 13+ is slightly more efficient than the '11-12 Tony used in your reference.
2. There is a decent amount of variability in energy used to charge from the wall so you'd need to repeat the test a couple times at least to be reasonably sure the LBC didn't either hit turtle early or cut off charging early because of cell imbalance.

 

[apacheguy]

Alright. LeafSpy purchase is in order. I have an iPhone. Do folks have a suggested OBDII Wifi module or will any of them work just fine?

1. The 13+ is slightly more efficient than the '11-12 Tony used in your reference.

Thanks for pointing that out, I missed that. Are better numbers available for the 13+ or am I the first to do this test?

 

[finman100]

http://www.ebay.com/itm/Super-Mini-...hash=item4d17dc4c71&item=331112795249&vxp=mtr

This is the exact one I've been using on my 2014 SV for the past year. Works great on my iPhone 5s running iOS 9.1 currently.

Wouldn't it be great if something like this was actually incorporated into the damn car in the first place? I mean knowing the kwh has been AWESOME. knowing how many GOM miles has been less than awesome. The percentage battery display is okay for the 2013s and up, but knowing kwh using Leafspy or Leafstat is superior for an EV.

Good luck!

Curt

 

[tkdbrusco]

As others have said, you need leaf spy and an OBD reader to do accurate measurements. Since you bought the car in the middle of winter, the battery will have lower numbers. Odds are that they pick back up with use and also in a few months when the temps increase.

 

[powersurge]

My friend, you can't say there is "degradation" on a 2 week old car... First, I am sure that with a new car, it will take a good number of charging cycles for the new battery to broken in. Also, 1.4KW is nothing to panic about. I cannot imagine that we can account for every watt of energy that the specs say is there. Just like when we get a flash memory card of, say, 32gb... We can never get the full amount because some or the capacity is taken up by other things. I would say, relax, enjoy your new car, you have a good warrantee to handle problems in the future.

 

[apacheguy]

Will this Wifi OBD scanner work?

http://www.amazon.com/Docooler%C2%AE-Wireless-Diagnostic-Scanner-iPhone4S/dp/B00DYOVXZ0

As others have said, you need leaf spy and an OBD reader to do accurate measurements. Since you bought the car in the middle of winter, the battery will have lower numbers. Odds are that they pick back up with use and also in a few months when the temps increase.

No. Temps were not an issue in my case. I conducted my test at 65 F. Argonne National Lab conducts their tests at 70 F. It is a scientifically sound comparison.

My friend, you can't say there is "degradation" on a 2 week old car... First, I am sure that with a new car, it will take a good number of charging cycles for the new battery to broken in. Also, 1.4KW is nothing to panic about. I cannot imagine that we can account for every watt of energy that the specs say is there. Just like when we get a flash memory card of, say, 32gb... We can never get the full amount because some or the capacity is taken up by other things. I would say, relax, enjoy your new car, you have a good warrantee to handle problems in the future.

Can you explain what you mean by Li-Ion batteries requiring a "break in" period? Never heard of this and I know a fair amount about them. If you could provide a reference to sustain your claim that would be appreciated.

 

[aarond12]

If you could provide a reference to sustain your claim that would be appreciated.

I think it's less that the battery needs to be broken in, and more that the BMS (battery management system) needs to find its sea legs. I'm certain that Nissan programmed the BMS to be conservative at first, learning the battery and then optimizing the current later. That's the only logical explanation why my health readings improved after the first couple of months with my car. You are correct that Li-Ion batteries don't need to be broken in, per se.

 

[apacheguy]

@aaron - That is a plausible explanation that I have considered. This whole thing was prompted by my SOC declining uncharacteristically quickly on a route that I did many, many times in my previous Leaf. I did notice that the final 10% capacity took a long time to consume suggesting the BMS may not have been properly calibrated.

I think what is going on is that 25.4 kWh number I referenced in the OP was with a 3.3 kW onboard charger. My car charged last night at 6 kW from the wall. If you factor in the additional ancillary overhead during charging and scale it by the ratio of the charge rates, it works out to an additional 1.2 kWh.

So, in other words, there is absolutely nothing wrong with my measurement or method, it is just the benchmark for comparison I chose was not apples to apples.

 

[Jefe]

Will this Wifi OBD scanner work?

http://www.amazon.com/Docooler%C2%AE-Wireless-Diagnostic-Scanner-iPhone4S/dp/B00DYOVXZ0

This is the one that Turbo3 currently recommends: http://www.amazon.com/LELink-Bluetooth-Energy-OBD-II-Diagnostic/dp/B00QJRYMFC
and I have been using this with his latest beta of LeafSpy on iPhone for a few days now, and it works great. Because it uses Bluetooth 4, it requires no pairing and it is a very low power draw.

 

[tkdbrusco]

My advice with the OBD reader is to buy a slim one that you can leave plugged in and not have to take out or hit with your leg while driving.

 

[TomT]

Be sure you get his (may still be in beta) iPhone version as the standard Android version will not work with the IPhone. Apple does not make it easy! I'm an Android person so my Apple info may be out of date or incorrect and thus YMMV...

Look here for the Apple discussion: http://www.mynissanleaf.com/viewtopic.php?f=44&t=18917

Alright. LeafSpy purchase is in order. I have an iPhone. Do folks have a suggested OBDII Wifi module or will any of them work just fine?

 

[apacheguy]

Well, I ended up buying this one a few days ago:

http://www.amazon.com/dp/B00WPW6BAE/ref=twister_B011NSXCMU?_encoding=UTF8&psc=1

Will post back with the results.

 

[dhanson865]

Alright. LeafSpy purchase is in order. I have an iPhone. Do folks have a suggested OBDII Wifi module or will any of them work just fine?

1. The 13+ is slightly more efficient than the '11-12 Tony used in your reference.

Thanks for pointing that out, I missed that. Are better numbers available for the 13+ or am I the first to do this test?

See the URLs in my sig for efficiency tests of the 3.6KW charger and 6.6KW charger. I'll quote the executive summary here

Full charge rate for the 3.6KW charger was around 88.x% (maybe 88.3 or so). Less efficient at full amps

Max efficiency for the 3.6KW charger was around 89.x% (maybe 89.5 or so). But around 12a not 16a.
Max efficiency for the 6.6KW charger was around 90.x% (maybe 90.5 or so). More amps is better on this one.

Max efficiency for the 120V with 3.6KW charger was around 86.x% (closer to 86.25 or so)
Max efficiency for the 120V with 6.6KW charger was around 78% (closer to 77.9% or so)

 

[apacheguy]

Thanks for those links. So using the Idaho numbers (which I assume account for overhead loss during charging?) then my usable capacity (97% extraction efficiency from the pack) is 21.2 kWh. I'll see how closely the LeafSpy agrees.

 

[dhanson865]

Thanks for those links. So using the Idaho numbers (which I assume account for overhead loss during charging?

They account for numbers from the wall vs coming out of the Leaf charger module. They don't account for losses elsewhere inside the Leaf such as:

* vampire drain by 12v or other user loads (radio, dash, cabin lights, headlights, heat, AC, OBDII adapter, etcetera)
* BMS overhead / battery charge inefficiency (load balancing, battery charging losses)
* Battery output losses

anything else I missed. They were just testing the J1772 port + internal charger and didn't test past that module.

 

[apacheguy]

LeafSpy screens. I'm a bit concerned about the 91% SOH with less than 500 miles. Anyone care to shed light?

Edit: Upon further reading, it appears that some 2013s showed mid 260s when new, but 2015s seem to show 280-295 gids. This is what I was expecting to see. And more like 22.5 kWh remaining, not 20.8. See for instance:

http://i.imgur.com/hWtOzEd.jpg

 

[tkdbrusco]

There are a bit low, but I'm not sure if you established any of the following prior?

1. How long the car sat on the lot before you bought it and when it was manufactured? You could have a car that has 500 miles, but a battery that is over a year old and has sat through a summer on the car lot. This makes a difference.

2. I think a lot of 2015 cars see a drop in max capacity during the winter.

3. How you charge the car can often impact the max reading

I wouldn't freak out to much at this point. I would wait to see how it reacts in April or may when it warms up.

To put your mind at ease, my 2015 car was 292 when new, dropped to 285 (approx) after a few thousand miles, when winter hit last year, with about 8K miles it was averaging 270-275, then during summer of 2015 with about 16K miles, it was back up to 280-288, and now that we are in another winter, with about 21K miles, the car has been between 263-271. My point is that even last year with minimal miles on my car it was tracking low 270s, but it came back up. Your SOH is at 91%, I see no reason why your pack won't be back into the 280s when the weather warms up.

Here are my most recent stats. 21,750mi

270 GIDS
20.92 kwh
97.05 SOC
86.75 SOH
87.93 HX
57.48 Ahr
55.9 degrees