long-term storage (months)

hieronymous said:

....At purchase (7/14) my Leaf had been in storage+transit for 26 months. AHr was 63.5 and SOH 96%. No significant evidence of age-related degradation there.......

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Just curious, what was the mileage on your Leaf when you purchased it and what was it's SOC? Now I know the dealer may have charged it before your test drive in which case you'd have no idea what it sat at for most of those 26 months, but it would be very interesting to know.
My '13 Leaf had also sat unsold for a bit over a year, it only had 30 miles on it and I have no idea what the SOC had been, the dealer was just taking it off the EVSE before my test drive. It's currently in the upper 80's for SOH and I generally stop charging at 80% although due to my driving needs I need to charge it to near 100% maybe once/week(or less).

jjeff said:

hieronymous said:

....At purchase (7/14) my Leaf had been in storage+transit for 26 months. AHr was 63.5 and SOH 96%. No significant evidence of age-related degradation there.......

Click to expand...

Just curious, what was the mileage on your Leaf when you purchased it and what was it's SOC? Now I know the dealer may have charged it before your test drive in which case you'd have no idea what it sat at for most of those 26 months, but it would be very interesting to know.
My '13 Leaf had also sat unsold for a bit over a year, it only had 30 miles on it and I have no idea what the SOC had been, the dealer was just taking it off the EVSE before my test drive. It's currently in the upper 80's for SOC and I generally stop charging at 80% although due to my driving needs I need to charge it to near 100% maybe once/week(or less).

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Almost identical, 33 miles, dealer charged to 80%, plus transported from Australia so charged there to be driven to the port and on board. From the Oz Leaf forum, however, some sales from the stockpile to local buyers had virtually nil loss with SOH at 98%, which supports my belief in li-ion battery stability over long periods of storage.

Can anyone point me to info about the maximum storage temperature allowed/advised to avoid battery degradation? We have 8 Leafs in stock that we'll be reselling but they are going to sit for a little while (perhaps a month or two). Luckily we have a climate controlled warehouse, but it is very expensive to cool the large space. Outside temps this week are hitting 107F.

We obviously have LeafSpy and I'm about to go over to the warehouse and check battery temps on the cars which have not been driven since they rolled off a car hauler. The cars are all 2013 and 2014's with 12 bars and miles ranging from 16-39K. We purposely bought 12 bar cars because we'd have a tough time selling one with less than 11 bars to a customer (having lived thru the pain of 9 bars in our personal 2013 Leaf).

Note that our storage facility is in the Central Valley of California where temperatures exceed 100F+ in the summer. Our customers are 80 miles to the west in the SF Bay Area where the temps are a beautiful and Leaf friendly 70-85F in the summer.

Again, my primary question is what is the optimal range for Leaf storage so we can try to stay at or near the top end of that range without spending hundreds of dollars on cooling the warehouse.

Unfortunately, the "optimum" storage temperature is probably much too low for you (in the 40-50 F range). However, storage below 90 F is probably sufficient, 80 F will certainly be better especially if stored more than a few months. Try to keep the traction battery charged to 3-4 bars out of the twelve. Bottom line, sell them as quick as possible or store them below 80 F. Also, if possible, put the 12 V batteries on a tender. I just got back from a long vacation and had mine just that way. Summer sucks on battery degradation.

We can handle storing at 90F which is much cooler than outside where temp in the sun is exceeding 120F. Also we're avoiding driving them, which is too bad since I am personally a huge fan of the Leaf. Had one on lease for 3 years. Still miss that car.

I took one out for a short drive just now. The battery temp rose to 94F. The bars on LeafSpy turned yellow then orange. The battery temp bars remained at 6.

Is the battery experiencing higher levels of degradation when operated above 90F for extended periods of time? If so why is the battery temp gauge reading 6 bars which implies everything is good.

Guess we'll do our reconditioning work (test drives for certification, tire changes, etc) in the very early mornings when it's cool.

I know this is a stupid suggestion, but if you have the repair facilities that can remove battery packs, those would be all that you'd need to keep cold...

Dropping the battery pack out if he car would be kinda crazy. We're not a Nissan dealer and wouldn't attempt any mechanical or electrical work on these cars. They are all under factory warranty which we'd probably void if we did. None of our service partners will work on them either.

Regardless the 8 cars we have now need only minor cosmetic reconditioning then hopefully they will all be sold to buyers in cooler parts of Northern CA soon.

Motarra said:

... Is the battery experiencing higher levels of degradation when operated above 90F for extended periods of time? If so why is the battery temp gauge reading 6 bars which implies everything is good.
...

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The temperature bars are a broad general guide.
Six bars does not mean everything is good.

But they are kind of exponential.
So five is very good.
Six is much worse, guessing twice the capacity loss rate of six.
And seven is getting really bad.
Again probably twice what six is.

But Nissan has not provided any details on capacity loss rates.
What I stated is a guess based on my capacity loss over five plus years.
Have lost four bars.
My guess is that 80%+ of that occurred with battery over 90F.
And half of that may have been over 100F.

What you need to worry abut is the average temp inside the warehouse over a given day and week, not the outside high temp. The battery packs are massive, and heat and cool slowly when not in use. If you can keep the *average* temp inside the warehouse to 80F or lower, that should be fine.