Long term EV storage procedure

[WetEV]

I'd leave the battery with more SOC than that; more like 60-80% (as stated above).

Li-ion battery calendar loss is dependant on SOC. The higher the SOC, the faster the loss. Yes, even down to 10%, the lowest tested.

M. Ecker et al. / Journal of Power Sources 248 (2014)

If you leave the car at 80% SOC, it isn't going to reach 10% SOC faster then if you initially left the car at 60% SOC.

???
Unless there is substantial vampire loss due to very low temperatures, a LEAF doesn't lose SOC very fast. SOH is lost faster at high SOC.

So only looking at calendar life, lower SOC is better, all the way down to 10%.

There isn't much reason to leave at 80%, again unless the temperature is low enough for the battery heater to activate. And if it is that cold, you might just want to leave at 100%, as calendar loss is very slow at subfreezing temperatures.

[Stanton]

There isn't much reason to leave at 80%, again unless the temperature is low enough for the battery heater to activate. And if it is that cold, you might just want to leave at 100%, as calendar loss is very slow at subfreezing temperatures.

I can't believe I'm reading this...on this site...from an experienced member...after all we know.
Never, ever, ever leave an EV charged to 100% more than a day or so...no matter what the temperature.
I still can't believe Nissan never re-instated the 80% charge option post MY2012 (I use it all the time).

[WetEV]

There isn't much reason to leave at 80%, again unless the temperature is low enough for the battery heater to activate. And if it is that cold, you might just want to leave at 100%, as calendar loss is very slow at subfreezing temperatures.

I can't believe I'm reading this...on this site...from an experienced member...after all we know.
Never, ever, ever leave an EV charged to 100% more than a day or so...no matter what the temperature.
I still can't believe Nissan never re-instated the 80% charge option post MY2012 (I use it all the time).

If the temperature is low enough for the battery heater to activate the EV will not be at 100% for long. If you want the car drive-able when you return, perhaps you might want more charge in the battery.

"100%" on the dash is more like 95% actual. 95% actual is about 3 times less calendar loss than 100% actual. 40% is about half the calendar loss of 95% actual. The LEAF, other than some early prototypes, will not allow charging to 100% actual.

At 0C, the loss will be roughly 1/4 the rate of at 20C. So keeping the charge level higher has an effect, but it is smaller because the temperature is lower. Keeping the battery at 95% actual at 0C is better than keeping the battery at 40% at 20C.

BTW, removing the charge option is close to top of my list of criticisms of the newer LEAFs. The etron allows any 10% from 50% to 100%. As my driving is close to home, I'm now using 60% charge limit and plugging in at 50% on the etron. My son with an essential job is driving the LEAF, and charges to 100% before departure, and comes home with 20% on the worst days in winter (wind, snow inland and cold), and over 50% on nice summer days.

[gncndad]

Sticking my nose where it doesn't belong, because my OCD issues, finally, are not with my cars!! HAHA!!

Dallas/Fort Worth region. I have charged to 100% virtually every single day that I've owned my 2015 LeafS, now at 37k miles, 11 bars on the GOM. Most days, it is driven to 45% capacity, rarely below 30%. We like 100% charge to allow us a spontaneous lengthy errand w/o range anxiety. Lifetime average 4.1 m/kWh, GOM shows 80-83m every single start-up.

It infrequently sits at 100% w/o being driven, with the exception of my FIRST year, when I left it plugged in for 5 straight weeks (July, garaged, no A/C...HOT!) .

I did lose my OEM battery after 4 years.

EDIT: I lost my OEM 12V battery after 4 years!!!!! I'm still on my OEM Lizard battery, with 11 bars.

...just muddying the water here with my single data point!

[Stanton]

It infrequently sits at 100% w/o being driven, with the exception of my FIRST year, when I left it plugged in for 5 straight weeks (July, garaged, no A/C...HOT!) .

I did lose my OEM battery after 4 years.

...just muddying the water here with my single data point!

In this case, your single data point is important: you lost a Lizard battery in 4 years (probably in large part to that 5 weeks it sat @100% in the Texas summer) where my (replacement) Lizard battery is now beyond 4 years @2BL (I lost my original battery after 4 years in Texas).

[arnis]

Never, ever, ever leave an EV charged to 100% more than a day or so...no matter what the temperature.

"no matter what the temperature" is not well defined by somebody who lives in TX.
If you have no experience with sub-zero Fahrenheit temperatures and batteries,
please don't say "no matter what temperature". Nothing really happens at -15*C with Li-ion,
no matter what temperature and what voltage. Calendar life...stops.

Also please keep the topic clean of endless fight over literally stupid never-ending topic
"Long term EV storage procedure" is not about that one thing that has overtaken 10+% of this forum.

Long term is about weeks and months... not days. Battery heater plays no role here.

[gncndad]

OOOPS!!!! Major typo in my post.

I lost my OEM 12V battery after 4 years, NOT THE LIZARD BATTERY. I'm still on my OEM Lizard battery.

Sorry for the confusion....

[Agamemnon]

My story - I bought a 2012 Nissan Leaf SL in 2017 with a replaced main traction battery (24kW) - I presume a Lizard kind - in Los Angeles.

Original 12V battery was getting drained if the car was sitting unused for more than 3 days, since I have replaced it with a newer one it can sit for a 5 days but beyond that I am risking on finding a dead car. Now I use C-tec battery charger when I have to leave the car unused for more than a week. I thought solar panel would trickle charge the 12V battery, but it doesn't seem to help much (if any).

When I bough my Leaf, SOH was 120%, after 3 years of use it is now down to 82%. I am thinking on sending this vehicle to my family summer house in Central Europe, where it would be stored in a shed when not used over winter(s). I do go and spend time over there every 1-2 years in summer when I plan on using the vehicle.

Would charging traction battery to 60% and disconnecting 12V battery is a best strategy or it would be better to have it on a 12V battery tender and connected? There will be no one interacting with the car while I am not there. Easiest would be not to have a charger for 12V battery as if there is some electrical issue and the charger is reset/turned off it might be years before I could get to the car.

Suggestions welcome.

[LeftieBiker]

How cold does it get where the car would be stored? Because if the pack temp (not the air temp) drops into the mid to high single digits Fahrenheit, the battery warmer will run and consume the charge eventually. Disconnecting the 12 volt battery should prevent that, but then the battery could possibly be damaged...

[arnis]

Li-ion battery will not be damaged if temperature drops to extreme cold.
Battery will not be able to discharge at extremely low temperatures, making vehicle undriveable until temperature rises above -15*C.
This is why some smaller devices stop working (phone, flashlight ....) that have Li-ion battery. And are totally fine later on.

Traction battery should be left to around 30-50% and 12V battery should be a) charged and b) disconnected from vehicle.

12V battery should be recharged after 6 months if stored for longer.
Leaf should be stored at temperatures not higher than 20*C.