The 62kWh Battery Topic

[Flyct]

Here is my 2021 efficiency so far by month. Pretty consistent (4.3 overall). July was a tad lower as we did more freeway with the S+ being repaired. 2020 was 4.2 for the whole year, so guessing my overall average comes down a touch in Dec.

https://drive.google.com/file/d/1y73iNIpihTsGyp9kGqQ7aaQkNE_ANNAm/view?usp=drivesdk

This 232 watts per mile feels similar to what I see others post in Tesla and Niro forums for average consumption. Bolt forums have suggested a bit less.

Doug,

Looking at your stats it looks like your average speed is 14.39 MPH (4521miles/314hours) 4.3 miles/kWh
Our stats for 2021 so far shows average speed 30.82 MPH (5792miles/185hours) with 3.8 miles/kWH

We all know speed kills range.

Probably over 75% of our miles are highway miles 60-65 mph, where we show average of 3.6 miles/kWh.

 

[DaveinOlyWA]

What do you think would happen if the bms didn't quarterly adjust the SOH? Think it would degrade the battery faster on full charges?

Too many "depends" to answer that. Full charges don't seem to be the problem as much as overcharging. Based on your need, I would think full charging regularly would be detrimental.

But heavy users who fully charge daily, DC often and have triple or quadruple the miles we have, are only slightly lower on the SOH curve with some above so a pat "will full charges hurt?" is simply too open ended.

There is also climate to consider. 40's seem to be somewhat affected by the heat while 62's seem immune but it could be simply a numbers game. What was obvious in a 24 might not be obvious in a 62 until we hit the same ratio of miles which in some cases could mean well over 200 miles a day?

 

[DougWantsALeaf]

Ok, next question.

How does the bms internally count the days? Have your updates been exactly 90 days or 3 months? (Not exclactly the same). I haven't measured daily, so I am not sure.

As the S+ doesn't have telematics, I wonder if detached packs still count the days or not.

 

[oxothuk]

I keep a log with daily LeafSpy readings. I've had two bms updates since I've owned my Leaf. The first one occurred 7/11-7/13, about 10 weeks after I purchased the car. The second one occurred 10/13-10/20, almost exactly 3 months after the previous one.

The second update coincided closely with a "Service EV System..." fault, which the dealer was unable to reproduce after keeping it in the shop a few days. I have no idea if this was somehow related to the bms update.

Since I bought the car I've seen the SOH drop by 5.2% over 5000 miles. If it continues at that rate I would reach warranty replacement at <30K miles.

 

[DougWantsALeaf]

Oxothuk, the first few bms updates are generally the worst, than it shows down or even occasionally reverses. My last 2 updates in my S+ have actually been up. My SoH is actually higher now than late March. It's one of the mysteries of the car. Miles and normal cycles dont seen to matter as much as time. In fact it feels like too few miles is actually worse for the battery....but we are still only 4 years into the gen 2 packs, so another 4 years will be very revealing.

Flynt, our SV+ does a not of waiting around for child pick ups every day, so I would not put too much stock in the running time.

 

[DaveinOlyWA]

Ok, next question.

How does the bms internally count the days? Have your updates been exactly 90 days or 3 months? (Not exclactly the same). I haven't measured daily, so I am not sure.

As the S+ doesn't have telematics, I wonder if detached packs still count the days or not.

If I target a 90 day window plus or minus a few days then yeah, its pretty close. I thought it was once a quarter but mine is drifting. The first adjustment started the 25th but my most recent one started and ended the 18th so I have drifted back a week in 2 years.

1/25- 2/2
4/25 - 4/28
7/23 - 7/24
10/22
1/20 - 1/23 MINUS 2.64% SOH :shock:
all those were negative

4/18 - 4/23 +2.08% SOH

7/18 - 7/21

10/18 +.49% SOH

I am about to do a 2 year write up and will likely have lost 1.6% since last year but interesting in that both OCT adjustments (which is my build month) were one day events? But if I go back Jan on the 24th, I am up 1.12% SOH as of today.

 

[DaveinOlyWA]

I keep a log with daily LeafSpy readings. I've had two bms updates since I've owned my Leaf. The first one occurred 7/11-7/13, about 10 weeks after I purchased the car. The second one occurred 10/13-10/20, almost exactly 3 months after the previous one.

The second update coincided closely with a "Service EV System..." fault, which the dealer was unable to reproduce after keeping it in the shop a few days. I have no idea if this was somehow related to the bms update.

Since I bought the car I've seen the SOH drop by 5.2% over 5000 miles. If it continues at that rate I would reach warranty replacement at <30K miles.

You won't. My 2 biggest drops happened in first 15 months. Since then, I am up 1.12% Its seems like most fall into a relatively narrow window the first two years. After that, we see divergence but generally due to edge cases; gig drivers, real low miles, etc.

Have seen some head scratchers. One guy got a 40 kwh and dropped below 90% within 15,000 miles. He just passed 90K and is at 87% so?

We have the guy in Palm Springs, lost a bar at 30,000 miles but I think he has an agenda... Def not in the norm for sure. We have almost 2 dozen over 100,000 miles on "40's" with 12 bars. Only 2 others have lost bars besides Palm Springs, one at 97,000 miles, the other at 105K? or so?

Either way, the battery degradation warranty is nothing but noise...

 

[SageBrush]

We have almost 2 dozen over 100,000 miles on "40's" with 12 bars.

That sounds *much* better than e.g. the 24 kWh LEAFs but two things are worth mentioning:

1. That first bar is ~ 16% of capacity so 'still 12 bars' is a wide range
2. The larger capacity LEAFs can be driven a lot more miles per day with similar inconvenience to the smaller capacity cars so the time based degradation may not have improved as much as is imagined.

 

[knightmb]

We have almost 2 dozen over 100,000 miles on "40's" with 12 bars.

That sounds *much* better than e.g. the 24 kWh LEAFs but two things are worth mentioning:

1. That first bar is ~ 16% of capacity so 'still 12 bars' is a wide range
2. The larger capacity LEAFs can be driven a lot more miles per day with similar inconvenience to the smaller capacity cars so the time based degradation may not have improved as much as is imagined.

Even if it is a "wear" variable, having more miles means the 40 kWh battery gets to 100,000 miles with less charge/discharge cycles than the 24 kWh battery could. But as we've seen, even those that would "baby" the 24 kWh battery pack would still see the same degradation, be it a little less, than those that were driving it daily and really wearing the pack out, like myself. I think it was just a function of old technology vs. new technology. Battery tech gets better and so does the lifespan of the pack. I'm not sure how old the "oldest" 40kWh pack is out there, my wife's 2018 seems to be close to that time, but only at 3.5 years old, I'll have a better answer then it reaches 8 years old like my first Leaf.

 

[SageBrush]

Even if it is a "wear" variable,

The opposite -- I am talking about the time variable.

Owners that drive a lot reduce the weighting of the time variable. That has always been true, but it is all the more true when the pack size is doubled. This is all good for them, but what about the people that are not high mileage rollers ?

The point I am making is that the LEAF battery is clearly improved for high mileage drivers simply by virtue of its larger capacity. Whether the pack chemistry and time based degradation has also improved is less certain.

 

[DaveinOlyWA]

Even if it is a "wear" variable,

The opposite -- I am talking about the time variable.

Owners that drive a lot reduce the weighting of the time variable. That has always been true, but it is all the more true when the pack size is doubled. This is all good for them, but what about the people that are not high mileage rollers ?

The point I am making is that the LEAF battery is clearly improved for high mileage drivers simply by virtue of its larger capacity. Whether the pack chemistry and time based degradation has also improved is less certain.

Agreed. The two WA high milers greatly exceeded the curve with huge display of improvement shown between the 2011 and 2015 24 kwh packs. The reality is driving a lot means less time at high SOC. Charging a lot means less time at very low SOC.

The latter is likely to hit TWO hundred thousand miles at 11 CPs

 

[knightmb]

The point I am making is that the LEAF battery is clearly improved for high mileage drivers simply by virtue of its larger capacity. Whether the pack chemistry and time based degradation has also improved is less certain.

I can agree with that, I don't know if bigger is better or bigger is just bigger.
So far, my wife has +33k miles on her 2018 and the pack is sitting at around 92% SOH. I've put nearly +27k miles on my 2020, just this year, I haven't even owed it for a full year yet and will probably surpass her mileage by the end of this year and the 36k warranty on the "everything" stuff, which seems kind of crazy, but so far so good for my experience. If I hit +100k miles in 3 years and the battery is still sitting in the +90%-ish SOH like my wife is after 3.5 years, I would consider it a win for more advanced battery technology, even though it would only be 1 data point among all the other Leaf out there, so I wouldn't be able to say everyone would be as lucky.

 

[DougWantsALeaf]

Sage

I think that is a valid point. The early 24 Leafs that made 100k miles were also 12 bars, but those feats were accomplished in 2 years. It certainly feels like time more than cycle impacts capacity with this chemistry. The good news is the number of 3+ year Leafs (and a few Pluses now) are crossing the warranty threshold with full bars. The time impact feels similar on the M3/MY forums as well. The initial 5% loss appears still surprises some new owners, not understanding that the curve flattens pretty fast.

Let's see what 4 more years brings.


As an aside, what happened to the Gen2 Leaf group on Facebook?

 

[DaveinOlyWA]

Well of course bigger is better. 24 kwh was NEVER enough for anything other than an errand car. The few like me who extended that is and always will be an edge case. Even my 30 kwh (which left the World at 30,000 miles AND 100% SOH) wasn't sufficient.

The 40 works if the weather isn't too extreme but the 62 is a game changer and NOT coincidentally, comes in at the same range as the base T3.

But the other thing is it works MUCH better in the heat. I am all but unable to hit 100º on the pack at this time of year under 400 miles. Tried twice. 2 25+ kwh DC sessions didn't do it. First session 40 mins, 32 kwh and pack went from 62 to 80. started at 6 TBs, ended at 6 TBs.

Its all about cell count. Now, its winter so this doesn't "seem" impressive other than to mention one of the trips I do "normally" at least 1-2 times a year and even in the 40 I was hitting 9-10 TBs at the end (not to mention at least one extra stop)

 

[Learjet]

another drop and that pesky cell keeps dropping

 

[DaveinOlyWA]

another drop and that pesky cell keeps dropping

You have a low Hx. Do you normally charge to full?

 

[Learjet]

I do a full charge about every 1,000 miles on average. I normally keep it between 20-80% most of the time. Remember this car sat on the dealers lot for a year before I bought it...no telling how the battery was maintained on the lot....I suspect 100% charged...since that is where it was when I dropped in unannounced to look at it. Car had only 20 miles or so on it when I bought it.

Range is good... shows anywhere between 208 to 230 miles on the GOM when fully charged.

 

[DaveinOlyWA]

I do a full charge about every 1,000 miles on average. I normally keep it between 20-80% most of the time. Remember this car sat on the dealers lot for a year before I bought it...no telling how the battery was maintained on the lot....I suspect 100% charged...since that is where it was when I dropped in unannounced to look at it. Car had only 20 miles or so on it when I bought it.

Range is good... shows anywhere between 208 to 230 miles on the GOM will fully charged.

Ok, this makes it obvious that DC charging elevates Hx among other things I am guessing...maybe warmth?

In looking at my Hx history, last winter it dropped (not a lot but neared 110...) and this was no DC charging at all, batt temps pretty much below 70º 100% of the time for 4 plus months, SOC never over 74%

I saw a small rise as we enter Spring still no DC charging but we had a VERY warmer than normal Spring with April exceeding average summer highs for over a week straight.

Now all that could be gibber... or not

 

[knightmb]

another drop and that pesky cell keeps dropping

Yeah, I had the same issue on mine when I bought it, but it was cell #3, doing the same thing, always way off in voltage from the others. It took about 2 gentle deep cycle discharges to finally get it in line. My wife's 40 kWh Leaf had the same issue with a lot of random cells, took 3 gentle deep cycle discharges to finally get her cells into shape. In the grade scheme of things, it may not make a big deal unless you want to try and squeeze out every last electron from the battery on the bottom end since the pack shuts off when any cell reaches 2.5V which can lead to a shutdown even before turtle mode happens in the right circumstances. :shock:

 

[DaveinOlyWA]

another drop and that pesky cell keeps dropping

Yeah, I had the same issue on mine when I bought it, but it was cell #3, doing the same thing, always way off in voltage from the others. It took about 2 gentle deep cycle discharges to finally get it in line. My wife's 40 kWh Leaf had the same issue with a lot of random cells, took 3 gentle deep cycle discharges to finally get her cells into shape. In the grade scheme of things, it may not make a big deal unless you want to try and squeeze out every last electron from the battery on the bottom end since the pack shuts off when any cell reaches 2.5V which can lead to a shutdown even before turtle mode happens in the right circumstances. :shock:

I have one cell that strays from the pack and has from day one. It is a bit "different" as the delta is greater at higher SOC and not noticeable in the mid SOC range.