2013 Low Battery Capacity AHr Battery Degradation

Re: Built 3/13 Delivered 3/31/13
Brad, using the code tag makes tables easier. HTH

bradbissell said:

Update on my battery degradation. Looks like my capacity has finally dipped below 100%.

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Capacity loss is fastest when the battery is newest. The first 6 months you can lose 5% capacity from new driving 1,000 mi/mo in Boston, so I'd say you're doing better than expected - but then who knows what your car read when it was delivered?

Check out the battery aging model if you haven't:
http://www.mynissanleaf.com/wiki/index.php?title=Battery_Capacity_Loss#Battery_Aging_Model" onclick="window.open(this.href);return false;

Boomer23 said:

This batch of battery packs in the recent (May 2013 build and later????) LEAFs appears to be different from the packs in the 2011 and 2012 cars and even from the early 2013 cars.

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The Nissan Phoenix discussions on August 24, 2013 indicated the 2013 pack chemistry is a bit better than 2011 / 2012, but not as good as the developmental available sometime in 2014 "Hot" battery.
Strictly speculation, but maybe the 2013 battery chemistry change was made in early May 2013, and not all model year 2013 LEAFs have the same battery chemistry. That would fit with measured small differences based on build date.
But also possible they made a software change, and that not all model year 2013 LEAFs have the same software.

TimLee said:

The Nissan Phoenix discussions on August 24, 2013 indicated the 2013 pack chemistry is a bit better than 2011 / 2012, but not as good as the developmental available sometime in 2014 "Hot" battery.
Strictly speculation, but maybe the 2013 battery chemistry change was made in early May 2013, and not all model year 2013 LEAFs have the same battery chemistry. That would fit with measured small differences based on build date.
But also possible they made a software change, and that not all model year 2013 LEAFs have the same software.

Click to expand...

Was it chemistry or was it the changes to module construction that allow for more rapid passive cooling (or a bit of both)?

Like many on this forum, I'm an engineer which means I'm a tool and tracking all my data and comparing it to the battery aging model. Based on the current trend, I should be at ~90% capacity at the end of my 2 year lease which is a little better than the aging model would indicate based on my 1250miles/month. Very happy with my LEAF and it appears to be very happy with the climate in Boston. At this rate the battery will hit EOL at ~10 years. I'm still not going to buy out the lease, but that is another story....

drees said:

TimLee said:

The Nissan Phoenix discussions on August 24, 2013 indicated the 2013 pack chemistry is a bit better than 2011 / 2012, but not as good as the developmental available sometime in 2014 "Hot" battery.
Strictly speculation, but maybe the 2013 battery chemistry change was made in early May 2013, and not all model year 2013 LEAFs have the same battery chemistry. That would fit with measured small differences based on build date.
But also possible they made a software change, and that not all model year 2013 LEAFs have the same software.

Click to expand...

Was it chemistry or was it the changes to module construction that allow for more rapid passive cooling (or a bit of both)?

Click to expand...

Could be both. I wasn't at the meeting, the quote stated by one attendee was "2013 battery has better temperature characteristics, and we should notice an improvement, but isn't as good as the 'Hot Battery'".

Perhaps they changed the chemistry in the 2013 battery to use the 2014 electrolyte and are waiting to change the polypropylene separator in 2014 for the "hot battery"?

TimLee said:

drees said:

TimLee said:

The Nissan Phoenix discussions on August 24, 2013 indicated the 2013 pack chemistry is a bit better than 2011 / 2012, but not as good as the developmental available sometime in 2014 "Hot" battery.
Strictly speculation, but maybe the 2013 battery chemistry change was made in early May 2013, and not all model year 2013 LEAFs have the same battery chemistry. That would fit with measured small differences based on build date.
But also possible they made a software change, and that not all model year 2013 LEAFs have the same software.

Click to expand...

Was it chemistry or was it the changes to module construction that allow for more rapid passive cooling (or a bit of both)?

Click to expand...

Could be both. I wasn't at the meeting, the quote stated by one attendee was "2013 battery has better temperature characteristics, and we should notice an improvement, but isn't as good as the 'Hot Battery'".

Click to expand...

So I have the new interim "Warm Battery"? I claim first use of that term! :lol:

As I continue to drive my 2013 LEAF SL (Built May 2013), and especially as I do more 100% charges, after a steady decline in readings, I'm seeing increases in AH and Health, rather than decreases that most people are reporting as time, and summer temperatures continue to go on.

I wanted to report this to add to the forum's information base about how at least one of the new packs is behaving over time. It is also interesting to look at how the AH readings have increased to 65.5 after reading 60.9 when I picked up the car at the dealership on June 15. If I had believed the AH reading that day at the dealership, I might have rejected the car as having a degraded or low capacity battery pack. Instead, the car is demonstrating a full 21 plus kWh on range tests to Turtle and measured kWh required to re-charge to 100%.

Here is a list of AH and Gids, with Health readings beginning at the point when the Health data became available in the App.

June 15...60.89 AH, 263 Gid at 100% (at delivery of 2013 LEAF at dealership)
June 16...61.63 AH, 267 Gid at 100%
June 17...63.25 AH, 218 Gid at 80%
June 19...62.83 AH, 216 Gid at 80%
June 20...62.42 AH, 271 Gid at 100%
June 21...63.71 AH, 277 Gid at 100%
June 27...65.33 AH, 284 Gid at 100%
June 28...65.22 AH, 225 Gid at 80%
July 1.....64.51 AH, 222 Gid at 80%
July 3.....64.03 AH, 220 Gid at 80%
July 7.....64.05 AH, 277 Gid at 100%
July 8.....64.35 AH, 223 Gid at 80%
July 12....63.65 AH, 220 Gid at 80%
July 15....64.06 AH, 221 Gid at 80%
July 18....63.16 AH, 274 Gid at 100%
July 23....62.72 AH, 215 Gid at 80%
July 28....61.89 AH, 214 Gid at 80%
Aug 1......61.27 AH, 210 Gid at 80%
Aug 6......60.65 AH, 208 Gid at 80%
Aug 10....62.13 AH, 269 Gid at 100%
Aug 11....63.01 AH, 271 Gid at 100%, 96.86 Health
Aug 14....62.01 AH, 269 Gid at 100%, 95.84 Health
Aug 17....61.8 AH, 268 Gid at 100%, 95.25 Health
Aug 23....61.7 AH, 212 Gid at 80%, 96.24 Health
Aug 30....62.13 AH, 269 Gid at 100%, 95.69 Health
Sept 7.....63.34 AH, 275 Gid at 100%, 97.29 Health
Sept 7.....63.73 AH, 278 Gid at 100%, 98.3 Health
Sept 11...63.43 AH, 218 Gid at 80%, 95.61 Health
Sept 14...63.19 AH, 274 Gid at 100%, 97.09 Health
Sept 14................ 274 Gid at 100%
Sept 14....64.04 AH, 283 Gid at 100%, 100.22 Health
Sept 15....65.51 AH, 100.22 Health
Sept 16...................225 Gid at 80%

This is interesting. Too early for the seasonal gid recovery. Could be that your car is so new it is still figuring out it's capacity in it's new environment. From my BCM resetting experiences, I know the cap bars have a time-constant of several months so if your car was reset prior to delivery you may be experiencing the same long-term training and happen to have a battery that is above the reset value.

Here is some of the data for a couple of months for my 2 "Warm Battery" Leafs !!

2013 S at 100% charge

Date Cap Hlth Gids
7/19 60.39 264
7/26 60.34 92.51 262
7/30 60.37 262
9/15 60.78 93.38 264 current odom 3100 miles


2013 SV at 100% charge

7/16 60.3
7/19 60.3 264 gids
7/27 60.83 93.46% 264
7/30 60.72 93.26 263
9/15 60.68 93.17 264 currnet odom 2800 miles

I haven't seen the increase in capacity that boomer has, maybe I need to charge to 100% more. Mostly charge to 80%

stjohnh said:

I haven't seen the increase in capacity that boomer has, maybe I need to charge to 100% more. Mostly charge to 80%

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My most recent readings were taken during a 225 mile trip that required three recharges from about 35% SOC to 100% using Level 2. I have found that successive 100% charges have resulted in higher Gid counts and higher AH readings.
Ingineer advised us two years ago that the most accurate Gid counts for full charge will be obtained by charging to 100% at least twice in succession without setting an end timer and allowing a few hours of plugged-in time for balancing after apparent charge completion. In the case of my recent trip, I did charge to 100% four times in a 48 hour period, but I disconnected the plug immediately after the last three of these charges. Rebalancing does clearly happen even when disconnected from mains power.

I did several 100% charges in a row and did see my capacity, GIDS and kwh go up a little to as high as 264 GIDS and 21.1kwh. But now I've hit a new low of 260 GIDS and 20.8kwh at 100% charge.

At this rate I should cross below 90% capacity in a few weeks, although it has suddenly cooled off.

Hard for me to judge if range is any worse since the car reported low capacity and health from the first time I checked it. I'm probably getting better at driving slow and efficiently. We drove 170 miles in one day. 85 miles each way. We recharged at a Nissan dealership to full and came back. Even after 85 miles, we were still showing about 17% left as reported by the car. 5.4mi/kwh reported by the car. Next time we charged to 100% the gom read 103 mile range. First time ever over 100 for us.

But alas our readings are consistently hitting new lows so I tend to believe them.

Just to add a bit more data, my 2013 SV (manufactured July, delivered Aug 3) has 63.6 AHr (average of 10 readings between 16-24 Sep and 830-1110 miles, using Leaf Spy). I have no earlier data. I rarely charge to 100%, and the only measurement I have for full charge is 277 GIDs.

What actually is measured to determine amp hours? Could the apparent variation in capacity among 2013 Leafs be mainly measurement error? It seems that posters with low capacity are seeing normal range.

My 2013 (manufactured June) hemorrhages AHr and Hlth between full charges.

However, full charging always recovers most of the "loss" and I don't feel that range is lower than it should be for a new LEAF.

Delivered AHr : 61.36 August 5
Highest observed AHr: 63.99 August 22
Last AHr the day following a full charge: 63.28 Sep 23
AHr today: 62.15

GIDs after 1st full charge, August 6: 268 (Highest pack temp ~84F)
Highest observed GIDs: August 21: 276
GIDs after last full charge: September 22: 265 (Highest pack temp ~71F)

Hlth has been all over the board. As high as 97.71% and as low as 92.7%. Was 97.21% the day after the latest full charge.
80% charges have ranged from 210 Gids to 219 Gids. Yesterday it was 217.

I would like to add the SOC as reported by LEAF Spy on a full charge has ALWAYS been 97.3%, but on 80% charges has varied from 79.0% to 80.5%.

The average cell-pair voltage after full charges is ~4.133.

These figures seem to be higher than pre-2013 LEAFs.

Edit: After Tony Williams' contribution, I erase the conjecture about the cell-pair voltages being even higher than early MY13 LEAFs.

Berlino said:

I would like to add the SOC as reported by LEAF Spy on a full charge has ALWAYS been 97.3%, but on 80% charges has varied from 79.0% to 80.5%.

The average cell voltage after full charges, is ~4.133.

These figures seem to be higher than pre-2013 LEAFs, and perhaps even greater than seen in early MY13 ones.

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The slightly higher cell-pair voltage is consistent with the 283-284 Gid readings on MY13 cars.

There might be another possibility, the date that car is assembled is different from the date the battery pack is manufactured.

That's a wild guess. Some 2013 cars might be using battery packs actually made for previous year's? since 60-62Ahr is quite close to that...

chrisie75 said:

There might be another possibility, the date that car is assembled is different from the date the battery pack is manufactured.

That's a wild guess. Some 2013 cars might be using battery packs actually made for previous year's? since 60-62Ahr is quite close to that...

Click to expand...

Well, I had thought that the 2013 Leafs were made in Smyrna from May on and in Japan before that. Also I read somewhere that the main battery "stuff" still comes in sheets from Japan, and the batteries are assembled from those sheets in Smyra.

in theory, once the cell is made, its 'life journey' begins. If new (or nearly new) cars show two and only two capacity values (assuming the measurements are reliable), that's quite possible they are made from two different batch of cells.

Although we all see some variation of capacity measurements in different temp./charging situations, but those differences wont be so significant, and this gap on the other hand, fits in battery life span curve quite well.

We all know Nissan has much higher expectation for 2012 sales which fell short. It wont surprise me that cells manufacturing goes ahead and have to wait for the actual car sales to catch up.

We probably could know better when later time, more new cars roll out.

stjohnh said:

chrisie75 said:

There might be another possibility, the date that car is assembled is different from the date the battery pack is manufactured.

That's a wild guess. Some 2013 cars might be using battery packs actually made for previous year's? since 60-62Ahr is quite close to that...

Click to expand...

Well, I had thought that the 2013 Leafs were made in Smyrna from May on and in Japan before that. Also I read somewhere that the main battery "stuff" still comes in sheets from Japan, and the batteries are assembled from those sheets in Smyra.

Click to expand...