SanCarlosJeff
Posts: 17
Joined: Tue Sep 25, 2018 10:14 am
Delivery Date: 24 Sep 2018
Leaf Number: 302391
Location: Northern CA

Re: Long term EV storage procedure

Wed Apr 15, 2020 8:53 am

The last time I drove my Leaf was March 14. I charged it to 100% that day and then unplugged it. This thread got me to thinking that I should go take a look at the charge level. I was very surprised/impressed to see that the battery charge is now at 99%.
-Jeff
Prius: 2005-2012
Volt: 2012-2018
Leaf:2018-??

User avatar
jlv
Moderator
Posts: 1344
Joined: Thu Apr 24, 2014 6:08 pm
Delivery Date: 30 Apr 2014
Leaf Number: 424487
Location: Massachusetts

Re: Long term EV storage procedure

Wed Apr 15, 2020 10:48 am

jlv wrote:
Thu Apr 09, 2020 12:14 pm
I personally don't know about the trickle charger. I never had 12V battery issues with my LEAF, while other people have reported lots of issues. I had an 2013 SL with the silly PV panel to top off the 12V; I'm not sure if that is why.
I heard from the current owner of my 2013 SL. He told me the 12V was low after the car sat unused (outside) for 3 weeks. But then again, it's still on the original 12V battery, presumably put into service when the car was mfg'd in December 2013.
LEAF '13 SL+Prem (mfg 12/13, leased 4/14, bought 5/17, sold 11/18) 34K mi, AHr 58, SOH 87%
Tesla S 75D (3/17)
Tesla X 100D (12/18)
93K 100% BEV miles since '14
ICE free since '18

cpmiller15
Posts: 4
Joined: Tue Apr 07, 2020 7:04 pm
Delivery Date: 27 Nov 2019

Re: Long term EV storage procedure

Wed Apr 15, 2020 12:05 pm

LeftieBiker wrote:
Tue Apr 14, 2020 12:40 pm
Ok, so:

- leaving the main battery charged at 60-80%
- with the car unplugged and
- with the 12V battery remaining connected

should technically be ok for 3 months during the summer (in Southern California)
Yes. I would suggest, though, that it be left closer to 60% than to 80%. 40-50% would be optimum, if you won't need to take it on a long trip right out of storage.
Thanks for all your help. Feeling much better about storing it now!

User avatar
Stanton
Forum Supporter
Posts: 2200
Joined: Thu Feb 03, 2011 10:56 am
Delivery Date: 01 Sep 2011
Leaf Number: 7458
Location: Plano, TX
Contact: Website Twitter

Re: Long term EV storage procedure

Thu Apr 16, 2020 7:26 am

SanCarlosJeff wrote:
Wed Apr 15, 2020 8:53 am
The last time I drove my Leaf was March 14. I charged it to 100% that day and then unplugged it. This thread got me to thinking that I should go take a look at the charge level. I was very surprised/impressed to see that the battery charge is now at 99%.
That's the point: the longer your battery sits near 100%, the the more its long-term health deteriorates.
Lithium batteries are designed to "hold their charge" (that's why they work so well in our cars), but don't like to be stored at/near 100% (especially in warm environments).
2011 Blue Ocean SV w/floor mats & window tint
12v LiFePO4 battery & FIAMM 74100 horns
Wet Okole seat covers (front)
Tor's low-power heater mod
2013 sun visor
3G modem upgrade
L2 EVSE Upgrade
Battery Pack replaced (Rev E) @51 months and 41k miles

WetEV
Posts: 3748
Joined: Fri May 04, 2012 8:25 am
Delivery Date: 16 Feb 2014
Location: Near Seattle, WA

Re: Long term EV storage procedure

Thu Apr 16, 2020 9:30 am

Stanton wrote:
Thu Apr 16, 2020 7:26 am
SanCarlosJeff wrote:
Wed Apr 15, 2020 8:53 am
The last time I drove my Leaf was March 14. I charged it to 100% that day and then unplugged it. This thread got me to thinking that I should go take a look at the charge level. I was very surprised/impressed to see that the battery charge is now at 99%.
That's the point: the longer your battery sits near 100%, the the more its long-term health deteriorates.
Lithium batteries are designed to "hold their charge" (that's why they work so well in our cars), but don't like to be stored at/near 100% (especially in warm environments).
TLDR: Correct.

This source is behind a paywall. Sorry.
Also is for a different chemistry, one that might had a use for a product I might have designed. Things are strange now. Remember that different chemistries have different properties, but generally similar behavior. These results are not directly usable for a LEAF, or for any other EV. This is not an automotive battery being tested.

http://dx.doi.org/10.1016/j.jpowsour.2013.09.143

The Leaf doesn't allow for an actual 100% charge, but only about 95%. The LEAF SOC gauge reports 100% at about 95% actual capacity, to say this another way.

For the cell tested in the above source, life at storage at 50C at 100% SOC was 107 days to 80% of initial capacity.
Life at 95% true SOC (or LEAF reported 100%) was a bit less than a year. Storage lifetime increased with decreasing SOC, exceeding 4 years at 50C at low SOC. Much longer calendar life at lower temperatures for all SOCs, see Arrhenius. However directly testing them becomes a challenge.

Now how does that apply to the LEAF? This isn't an automotive battery, but the same general principal does apply. Longer life at lower SOC.
Very bad things also happen at low SOC, below about 30%, but not due to calendar losses, but rather due to cycling losses and probable Li plating.

So store the traction battery at about 40% SOC, unless you might need to do a significant drive without charging. Avoid storage above about 70%, if you can help it. Avoid discharge below 30% SOC, if you can help it. 20% SOC isn't so bad, but 10% SOC and 5% are worse.
Last edited by WetEV on Thu Apr 16, 2020 1:27 pm, edited 1 time in total.
WetEV
#49
Most everything around here is wet during the rainy season. And the rainy season is long.
2012 Leaf SL Red (Totaled)
2014 Leaf SL Red
2019 eTron Blue

frontrangeleaf
Posts: 115
Joined: Sat Aug 03, 2019 10:07 am
Delivery Date: 08 Jul 2019
Location: Denver Area

Re: Long term EV storage procedure

Thu Apr 16, 2020 10:38 am

WetEV wrote:
Thu Apr 16, 2020 9:30 am
Stanton wrote:
Thu Apr 16, 2020 7:26 am
SanCarlosJeff wrote:
Wed Apr 15, 2020 8:53 am
The last time I drove my Leaf was March 14. I charged it to 100% that day and then unplugged it. This thread got me to thinking that I should go take a look at the charge level. I was very surprised/impressed to see that the battery charge is now at 99%.
That's the point: the longer your battery sits near 100%, the the more its long-term health deteriorates.
Lithium batteries are designed to "hold their charge" (that's why they work so well in our cars), but don't like to be stored at/near 100% (especially in warm environments).
The Leaf doesn't allow for an actual 100% charge, but only about 95%. The LEAF SOC gauge reports 100% at about 95% actual capacity, to say this another way.

[snip] store the traction battery at about 40% SOC, unless you might need to do a significant drive without charging. Avoid storage above about 70%, if you can help it. Avoid discharge below 30%, if you can help it.
This would seem to imply that unless new battery technologies get markedly better with respect to degradation, we will eventually end up in a world where we drive around with vastly larger batteries than nominally necessary in order to preserve battery life, as costs come down. Batteries with 15-20% reserve would seem to be one solution - that's what you're effectively suggesting isn't it? Drive your car between 30 and 70% charge, i.e. use 40% of available range unless otherwise needed. We've been doing 25-75% more recently, as we've gained experience.

Looking farther forward, manufacturing economies of scale will kick in enough, and we'll just replace a worn out battery every 80k miles or something. It will be interesting to see how things shake out. But for now, it would seem that battery manufacturing capacity is lagging demand.
Empty-nesters - NW Denver-Boulder Area

2019 Leaf SL Plus
2015 Audi Q5 TDI
2007 BMW Z4 3.0Si
2012 VW GTI

WetEV
Posts: 3748
Joined: Fri May 04, 2012 8:25 am
Delivery Date: 16 Feb 2014
Location: Near Seattle, WA

Re: Long term EV storage procedure

Thu Apr 16, 2020 10:09 pm

frontrangeleaf wrote:
Thu Apr 16, 2020 10:38 am
WetEV wrote:
Thu Apr 16, 2020 9:30 am
[snip] store the traction battery at about 40% SOC, unless you might need to do a significant drive without charging. Avoid storage above about 70%, if you can help it. Avoid discharge below 30%, if you can help it.
This would seem to imply that unless new battery technologies get markedly better with respect to degradation, we will eventually end up in a world where we drive around with vastly larger batteries than nominally necessary in order to preserve battery life, as costs come down. Batteries with 15-20% reserve would seem to be one solution - that's what you're effectively suggesting isn't it? Drive your car between 30 and 70% charge, i.e. use 40% of available range unless otherwise needed. We've been doing 25-75% more recently, as we've gained experience.

Looking farther forward, manufacturing economies of scale will kick in enough, and we'll just replace a worn out battery every 80k miles or something. It will be interesting to see how things shake out. But for now, it would seem that battery manufacturing capacity is lagging demand.
Batteries have gotten markedly better, and are likely to continue to become better with respect to degradation.

25% to 75% is better than deeper cycles. Mostly you should be trying to do this or a shallower cycle for the regular driving you do to get better battery life. This was true for the early Li-ion batteries and is still true for current batteries. The shallower the cycle the better in the center of the battery capacity.

Battery manufacturing capacity is and needs to be ramping up to keep up with demand.
WetEV
#49
Most everything around here is wet during the rainy season. And the rainy season is long.
2012 Leaf SL Red (Totaled)
2014 Leaf SL Red
2019 eTron Blue

WetEV
Posts: 3748
Joined: Fri May 04, 2012 8:25 am
Delivery Date: 16 Feb 2014
Location: Near Seattle, WA

Re: Long term EV storage procedure

Tue Apr 21, 2020 6:39 am

jlv wrote:
Wed Apr 08, 2020 9:22 am
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)
WetEV
#49
Most everything around here is wet during the rainy season. And the rainy season is long.
2012 Leaf SL Red (Totaled)
2014 Leaf SL Red
2019 eTron Blue

LeftieBiker
Moderator
Posts: 14896
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 30 Apr 2018
Location: Upstate New York, US

Re: Long term EV storage procedure

Tue Apr 21, 2020 1:33 pm

WetEV wrote:
Tue Apr 21, 2020 6:39 am
jlv wrote:
Wed Apr 08, 2020 9:22 am
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)
This doesn't seem to apply well to the post 3/2013 Leaf packs. The Wolf and Lizard packs have little calendar loss unless charged to near 100%, and the post-Lizard 30 and 40kwh packs seem to have other issues that don't have much if anything to do with storage SOC, again as long as it isn't very high.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

User avatar
jlv
Moderator
Posts: 1344
Joined: Thu Apr 24, 2014 6:08 pm
Delivery Date: 30 Apr 2014
Leaf Number: 424487
Location: Massachusetts

Re: Long term EV storage procedure

Wed Apr 22, 2020 7:45 am

WetEV wrote:
Tue Apr 21, 2020 6:39 am
jlv wrote:
Wed Apr 08, 2020 9:22 am
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.
LEAF '13 SL+Prem (mfg 12/13, leased 4/14, bought 5/17, sold 11/18) 34K mi, AHr 58, SOH 87%
Tesla S 75D (3/17)
Tesla X 100D (12/18)
93K 100% BEV miles since '14
ICE free since '18

Return to “Tips & Tricks”