Rapid acceleration of battery degradation in year of light use

I bought a 2015 S in January 2018 with these leafspy stats:

SOH 91.68%
HX 84.77%
AHr 56.93
Odo 34,600
4 quick charges & 2661 L1/L2
15mV voltage range
This was at a battery temp around 25F and SOC 74.6%

I was extremely happy with this purchase considering I was still above 90% and I got a decent price, and seemed typical for 2015's that everyone speaks highly of battery-wise.

However, now a year and a bit later:
SOH 84.61%
HX 72.94%
AHr 52.54
Odo 37,200
4 quick charges & 2736 L1/L2
10mV voltage range
Battery temp around 53F and SOC 67.6%

My commute is only about 5 miles round trip. I only charge once or twice (in winter) a week or so, to limit amount of time the battery stays at high charge %. I do charge to 100% to let it balance, but only the night before I know I'll drive it to take the top off the charge so it doesn't sit above 95% for more than a day ever.

So it lost 8% over 3 years of a lease charging about 2.5x a day and 34K miles, but then I lose another 7% over 75 charge cycles and 2600 miles.

Advice at this point? I have no chademo chargers in my city. Currently I always charge on L1 since running 240 to my garage would be incredibly expensive because of my house layout. The options that occur to me:
1) Start charging to 100% every night (even though that's counter-intuitive) but that's most likely what was being done for the first 3 years with 2661 charge cycles.
2) Get a proper EVSE even at L1 with charge timer and limit it to 1-1.5 hours each night, and try to hold battery charge around 30-40% range as some have suggested, though I think this is more just tricking the BMS rather than helping protect battery life.
3) Try to get a deep discharge cycle (<20%) in followed by the fastest (6.6KW in this case) charge I can find to see if that helps, maybe try to do this once or twice a month for a while.
4) I rarely run below 40%, maybe I have a weak cell that the BMS is picking up on, and if I did even a single deep discharge that would present itself more clearly in the leafspy report?
5) Just accept I'm going to lose 6-7% per year now for some reason, I'll still be able to get around town (15 miles max in a day ever I think) for another 5+ years even at this rate though I was hoping the car would have some value in 4-5 years and not be completely worthless.

Any advice is appreciated, thanks! I do love this car but I'm obviously doing something wrong. I'd like to try to correct things before I lose the first bar if possible.

The big question here is: what is your climate like? Where (city, state) do you live? I'm guessing that you have hot summers and lots of warm nights..?

Sorry, can't believe I left that out. US midwest, Iowa. So we did have a pretty hot August last year. But the garage is attached and stays fairly reasonable, I don't think I ever saw more than 6 battery bars even after sitting in the sun all day at work, which means never got above 100F, right?

I'm pretty sure the lease was in somewhere around Tennessee, so it was likely hotter the first 3 years than this last year.

Similarly, we had an extremely cold January, but I kept a close eye on temperatures in the garage and I'd be surprised if the battery heater ever had to run at night, maybe one particular 3 day stretch. So I doubt it was damaged due to cold either.

The 2015 has the more heat-resistant "Lizard" pack, as you probably know, but that heat resistance is not so great in places where it gets really Hot in the daytime, and especially in places (Like Hawaii) where it gets warm in the daytime and stays warm at night. Did you happen to check your pack's temp "gauge" in the morning, in Summer?

Sorry that you didn't know those of us testing the batteries. Trade it in for a vehicle brand that has liquid TMS. Nissan is currently not making any cars with long lasting batteries. Maybe sometime in their future they will. Until then, many more of us will continue to be duped into buying a quickly depreciating car with a short lifespan. Sorry to say, you are not the first and will not be the last. Yes, I was really smart, I own 2 of them but there weren't as many choices back then. I was just happy Nissan brought an electric vehicle to market. Your other alternative is to replace the battery ($8,500) for another short lived battery when you need a new one. You will be underwater but you will have the use of the car around another 5ish years. Good luck!

The above post is, shall we say, a little on the gloomy side. If you can find a way to cool the car off at night (like leaving it outdoors on cool nights) you may well get another 5 years before the range drops a huge amount. The formula for long life for a Lizard pack is:

* Don't let the pack stay hot for many hours.

* Don't let it sit for hours in warm weather (or at all, if possible)at 100% indicated charge.

* Do NOT do both of the above life-shortening things at once.

OP: you are doing the right things so at this point I suggest that you stop monitoring degradation if it causes you angst. Your car will serve your current use profile for years and years.

You have it good compared to so many other LEAF owners.

Yeah I definitely was aware of the limitations of the leaf's battery technology when I bought the car. But not leaving it at 100%, not living in the southwest, not quick charging, and considering it only lost 8% over 30k miles while running in a hotter climate, I don't think I'm all that naive for being slightly surprised by the sudden drop.

I was strongly considering getting some automatic ventilation for the garage that would kick in in the summer anytime the garage is warmer than the outside to try to help cool it down, that could help. And maybe with a little charge timer trickery I can stay below 80% more consistently when the weather is hot, and only let it reach 100% to balance maybe bi-weekly or monthly, and only do that when we have a few cooler days.

Much more fiddling with that will probably just turn it into a source of stress/irritation which would be sad since I love driving it.

I'll also add that the SoC LEAF battery meters are far from accurate so there very well be less actual degradation than you measured this year. You can either trend for a longer period or do a charge test at a place like Chargepoint that give accurate energy draw from the meter.

LeftieBiker said:

The above post is, shall we say, a little on the gloomy side. If you can find a way to cool the car off at night (like leaving it outdoors on cool nights) you may well get another 5 years before the range drops a huge amount. The formula for long life for a Lizard pack is:

* Don't let the pack stay hot for many hours.

* Don't let it sit for hours in warm weather (or at all, if possible)at 100% indicated charge.

* Do NOT do both of the above life-shortening things at once.

Click to expand...

Doing those things, can we say, although helpful, are wildly optimistic to gain an additional 5 years.

gridstop said:

I bought a 2015 S in January 2018 with these leafspy stats:

Click to expand...

SageBrush said:

I'll also add that the SoC LEAF battery meters are far from accurate so there very well be less actual degradation than you measured this year.

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Although SOH is displayed by LeafSpy to two decimal places, it is accurate to less than +-3% at best. This is the estimated SOH that LeafSpy reads from the BMS or LBC. It is not measured value, but is estimated from other measurements, and can be off for a list of reasons.

So you might have gone from 94% to 81%, but I doubt that.

Or from 88% to 87%. Also doubtful, but because of the shift to L1 charging, perhaps somewhat more likely.

Several things can affect estimated SOH by a few percent. DCQC can raise estimated SOH. L1 charging seems to lower estimated SOH. Driving pattern can also affect the estimated SOH. Real SOH, kWh and Amp Hrs stored (with a carefully controlled recharge test, or a carefully controlled range test) don't seem to be affected, but the reported numbers change. SOH seems higher in colder weather, and lower in warmer weather.

You don't seem to be doing anything badly wrong...

Tesla Trolls will be happy to tell you that a $120k Model S will solve all your problems. Until the battery explodes, that is.

My brother has two Teslas, a model S and a model 3. He says the same thing, get a model 3 for "the same money"! DUH!

But its not really the "same" money. a model three with autopilot and non-black color is what, 38 to 39k? And tax credits and rebates are now a lot lower for it. So out the door MAYBE 30-32k? Plus you have to like the model 3 - the exterior I like, but the interior I do not. YMMV but I actually like having a gauge cluster in front of me, not just a screen in the center of the car. As I said, YMMV.

Now what does a new or used leaf cost? I'm currently looking at 2015 Nissan leafs. carmax is moving one for me to look at, around 9-10k with less than 30k miles. Still has full battery bars though I suspect its probably close to loosing the first one. Still, not a bad price.

But I have also discovered a new leaf in my area, there are 17500 US $ of rebates and discounts, Not including any dealer discount.
So I could plausibly walk out of a dealer, after taxes, for a 2019 SV leaf for 15k. Maybe 17k with tech and Weather Package.
For a new 2019!

I live in a hot area, so I know Nissan's battery won't last, but as far as I can tell there is nothing to keep me a year from now from doing it all over. Yes the Leaf's 1 year trade-in will be crappy, but I would only need to get 15-17k to come out ahead each year.

Anyway, my point is that comparing a car that costs ME 17k to a car that costs ME 30+k is not a real comparison.




If you are curious, these are the incentives where I live:

Fed Tax credit - $7500
State Rebate - $2500
East Kern Air District Rebate - $3000
SCE Rebate - $1000
Nissan SCE Leaf Discount - $3500

gridstop said:

2) Get a proper EVSE even at L1 with charge timer and limit it to 1-1.5 hours each night, and try to hold battery charge around 30-40% range as some have suggested, though I think this is more just tricking the BMS rather than helping protect battery life.

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There may be factors that affect the indicated SOH of the battery but all the credible evidence shows that all else being equal, keeping the battery at a lower charge level reduces the (inevitable) degradation of the battery. This is especially true when the temperatures are higher.

I mostly keep my Leaf between 20% and 80% SOC but this summer I'm planning to try to keep it below 50% SOC as much as possible. My driving is low enough and I have lots of places to charge (for free ! :mrgreen: ) so I'm not worried about getting stuck at turtle somewhere.

danrjones said:

My brother has two Teslas, a model S and a model 3. He says the same thing, get a model 3 for "the same money"! DUH!

But its not really the "same" money. a model three with autopilot and non-black color is what, 38 to 39k? And tax credits and rebates are now a lot lower for it. So out the door MAYBE 30-32k? Plus you have to like the model 3 - the exterior I like, but the interior I do not. YMMV but I actually like having a gauge cluster in front of me, not just a screen in the center of the car. As I said, YMMV.

Now what does a new or used leaf cost? I'm currently looking at 2015 Nissan leafs. carmax is moving one for me to look at, around 9-10k with less than 30k miles. Still has full battery bars though I suspect its probably close to loosing the first one. Still, not a bad price.

But I have also discovered a new leaf in my area, there are 17500 US $ of rebates and discounts, Not including any dealer discount.
So I could plausibly walk out of a dealer, after taxes, for a 2019 SV leaf for 15k. Maybe 17k with tech and Weather Package.
For a new 2019!

I live in a hot area, so I know Nissan's battery won't last, but as far as I can tell there is nothing to keep me a year from now from doing it all over. Yes the Leaf's 1 year trade-in will be crappy, but I would only need to get 15-17k to come out ahead each year.

Anyway, my point is that comparing a car that costs ME 17k to a car that costs ME 30+k is not a real comparison.




If you are curious, these are the incentives where I live:

Fed Tax credit - $7500
State Rebate - $2500
East Kern Air District Rebate - $3000
SCE Rebate - $1000
Nissan SCE Leaf Discount - $3500

Click to expand...

The Leaf sounds like a no brainer if it fits your commuting needs. I would conservatively assume 5% capacity loss per year. If your range needs are met by 70% of the new capacity, then it's a great deal. Even better than the 2015 possibly.

webb14leafs said:

The Leaf sounds like a no brainer if it fits your commuting needs. I would conservatively assume 5% capacity loss per year. If your range needs are met by 70% of the new capacity, then it's a great deal. Even better than the 2015 possibly.

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Perhaps I'm pessimistic, but I'd assume battery loss around 7-10% in a hot area (AZ, etc). I think 5% is quite reasonable in other regions. So I'd want it to handle my commuting with only 50% of its capacity, assuming it's going to last 5-7 years.

Still, I think the OP makes a good case why the Nissan is a better buy than a Tesla, for him, and I wouldn't dispute that, even though the Tesla will likely last longer. Even if the Leaf's value went to 0 (which it won't--even the metal has some value), the Tesla would have to retain 15k value to be a break even (financially speaking). Once you account for interest and growth on the initial 15k difference, the Tesla will never win.

The Tesla will be more fun to drive, although the Leaf is fantastically fun to drive compared to an ICE.

Below is the "degradation" in amp-hours for my 2012 Leaf with a replacement "Lizard" battery in Nov. 2016. Totally different climate, similar usage (light), garage stored, L2 charging only. However, the seasonal ups/downs are so consistent (will have the third "hump" in a couple of months) that indicates (in my case) that the slow average shift in battery temperatures has a significant influence on amp-hr readings.

Since you have only points in time readings - at essentially the same time of the year, the "seasonal" ups and downs are not likely influencing your perceived degradation. However, I would recommend that you do a similar "plot" in the future to understand better how much seasonal variation in your situation exists. It is possible you will see significant "recovery" due to higher average battery temps in the spring/summer/fall. In Houston, we don't have anything but summer except for 3 months of cold,wet winter :mrgreen:



BTW, the amp-hr reading is above 54.5 currently - and we have had a relatively cool spring - so I expect a fairly sharp rise in the next couple of months.

Lothsahn said:

webb14leafs said:

The Leaf sounds like a no brainer if it fits your commuting needs. I would conservatively assume 5% capacity loss per year. If your range needs are met by 70% of the new capacity, then it's a great deal. Even better than the 2015 possibly.

Click to expand...

Perhaps I'm pessimistic, but I'd assume battery loss around 7-10% in a hot area (AZ, etc). I think 5% is quite reasonable in other regions. So I'd want it to handle my commuting with only 50% of its capacity, assuming it's going to last 5-7 years.

Still, I think the OP makes a good case why the Nissan is a better buy than a Tesla, for him, and I wouldn't dispute that, even though the Tesla will likely last longer. Even if the Leaf's value went to 0 (which it won't--even the metal has some value), the Tesla would have to retain 15k value to be a break even (financially speaking). Once you account for interest and growth on the initial 15k difference, the Tesla will never win.

The Tesla will be more fun to drive, although the Leaf is fantastically fun to drive compared to an ICE.

Click to expand...

I live in south florida and mine is right at 5%/year. It seems to be concentrated from May to September though. I lose around 4% during those months, and then only 1% during the cooler months.

It also depends on a lot of variables. Will you park it in the sun all day? Will you charge at night, or during the day (while parked in the sun)? Will you do a lot of fast-charging?

I think there is a lot of info on the boards about how much degradation to expect in Arizona. You might want to wait until there's more data on the newer battery chemistry.

Lothsahn said:

webb14leafs said:

The Leaf sounds like a no brainer if it fits your commuting needs. I would conservatively assume 5% capacity loss per year. If your range needs are met by 70% of the new capacity, then it's a great deal. Even better than the 2015 possibly.

Click to expand...

Perhaps I'm pessimistic, but I'd assume battery loss around 7-10% in a hot area (AZ, etc). I think 5% is quite reasonable in other regions. So I'd want it to handle my commuting with only 50% of its capacity, assuming it's going to last 5-7 years.

Click to expand...

That sounds like ~ $5k depreciation a year to me. I expect my Tesla Model 3 to be half that or less by the time its useful life is over.

SageBrush said:

Lothsahn said:

webb14leafs said:

The Leaf sounds like a no brainer if it fits your commuting needs. I would conservatively assume 5% capacity loss per year. If your range needs are met by 70% of the new capacity, then it's a great deal. Even better than the 2015 possibly.

Click to expand...

Perhaps I'm pessimistic, but I'd assume battery loss around 7-10% in a hot area (AZ, etc). I think 5% is quite reasonable in other regions. So I'd want it to handle my commuting with only 50% of its capacity, assuming it's going to last 5-7 years.

Click to expand...

That sounds like ~ $5k depreciation a year to me. I expect my Tesla Model 3 to be half that or less by the time its useful life is over.

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Not if his purchase price after all incentives is only $17K. Not sure what model he's talking about so that may not be the final amount.

Here in Florida I could buy a new 2018 SV for $27,900. Knock of the tax incentive, 0 percent financing and no delivery fee and I'm looking at less than half the price of a standard range + model 3. I would much rather have the increased range, styling, charging infrastructure, and battery reliability that comes with a Tesla. I'm just not sure that's worth another $20K.

webb14leafs said:

Here in Florida I could buy a new 2018 SV for $27,900. Knock of the tax incentive, 0 percent financing and no delivery fee and I'm looking at less than half the price of a standard range + model 3. I would much rather have the increased range, styling, charging infrastructure, and battery reliability that comes with a Tesla. I'm just not sure that's worth another $20K.

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You say that the LEAF is good for 5 - 7 years, so that implies a break-even of 10 - 14 years for the Tesla.

That matches up pretty well with my prior estimates. As you say though, the Tesla is so much more car that it was an easy choice for me. Specifically, we use the car for trips outside the city, usually about 200 - 250 miles each way. A LEAF would have forced us to either keep another car for long(er) trips or take ICE rentals