DaveinOlyWA
Posts: 15148
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Nov 2019
Leaf Number: 319862
Location: Olympia, WA
Contact: Website

Re: Conditioning Your Battery / Keeping as Healthy as Possible

Sat Nov 21, 2020 9:57 am

fromAtoB wrote:
Sat Nov 21, 2020 9:17 am
Hi. I’ve spent about two hours this morning reading about Leaf charging and Li ion batteries. A lot of posts and information out there is years old and technologies improve.

My Leaf Plus manual had no recommendations about SOC range.

We bought our Leaf+ in April or May of 2019 when the 62 KWHr (?) batteries were still new but I’m not clear whether the technology changes much. And the last post in this thread is from May 2019.

So...my understanding is that the common wisdom from informed knowledge is that, as driving needs allow, it is better to keep SOC between roughly 20% and 80% and not fully discharge or charge to 100%.

And .... that applies also to the Leaf Plus 62 KWHr battery...is that right?

Thanks.
Better; yes. Best; no

Technologies improve sure but don't change physics. ATM, technology is only minimizing the damage we cause. EVERY EV manufacturer has custom charge settings some as low as 40% and there is a reason for that.

A few things to consider;
There is no need to fully cycle the pack
There is no need to top end balance the pack
Lead Acid wants to be topped off, NiCad has charge memory issues. Li has none of that.

One thing the Plus provides is more options for battery management. Not all of us can spend 20 seconds wandering out to the garage to start a charge on our car. If you can, then you should charge every day. If you aren't that means you are charging to a higher level than you need needlessly.

If you can't charge at home or work, then you have a challenge as long as you aren't driving 100 miles a day that is "doable" I did it with 24 and 30 kwh packs. (Had charging at home but drove WAY over 100 miles several times a week) so 62 kwh is a breeze.

So, live in the middle. MANY studies show that more frequent shallower charging sessions are better than less frequent deeper charging sessions. So 30-50% if you don't drive much. 20-70% if you do. But its all relative. 20% seems "risky" and I have to laugh at that. Even in winter, that is a 40 mile buffer AFTER pulling into my garage. I spent years pulling into my garage with less than 10 GIDs left (realize the last 4-5 are very hard to access)
2011 SL; 44,598 mi, 87% SOH. 2013 S; 44,840 mi, 91% SOH. 2016 S30; 29,413 mi, 99% SOH. 2018 S; 25,185 mi, SOH 92.23%. 2019 S Plus; 14,342.8 mi, 93.16% SOH
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

LeftieBiker
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Re: Conditioning Your Battery / Keeping as Healthy as Possible

Sat Nov 21, 2020 2:16 pm

To put it more succinctly: 25% is better than 20% as a 'floor' for SOC. 20% gets suggested mainly as a compromise for 24kwh Leaf drivers so they have a decent range available. If you go down to 20% or less, recharge immediately back to 25% or more when the trip ends. That way there is no noticeable damage to the pack.
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.

fromAtoB
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Re: Conditioning Your Battery / Keeping as Healthy as Possible

Sun Nov 22, 2020 7:50 am

Dave and Leftie....this is helpful. Thank you!
2015 Leaf, four year lease then returned.
2019 Leaf Plus, blue.

SageBrush
Posts: 5377
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Delivery Date: 13 Feb 2017
Location: NM

Re: Conditioning Your Battery / Keeping as Healthy as Possible

Sun Nov 22, 2020 12:29 pm

I am not aware of ANY studies that can be used to quantify longevity differences between these cycle schedules
20 - 80
20 - 70
25 - 70
25 - 80
30 - 70
30 - 80

Take dogmatic assertions with a gain of salt unless they have links to source references to back them up.

The best I am aware came from Prof Jeff Dahn, given as an answer to a twitter question asking how to fully optimize battery longevity in a Tesla battery. His answer was to cycle around 50%, meaning
Always at 50% is best; if not then
45 - 55; if not then
40 - 60; if not then
35 - 65, ....
https://insideevs.com/news/334778/tesla ... ife-video/

HOWEVER, Dahn did not quantify how much longevity is lost as the cycling window increases. Mainstream opinion seems to be that cycling out to as far as 20 - 80 has minimal effect, and becomes noticeable with frequent wider swings. Which is fine and dandy so far as it goes, but you HAVE to keep in mind the underlying assumption all else kept equal. Which never is true ! The other key variables are battery temperature and time spent at SoC > ~ 80%. If you do a Dahn best job at cycling and ignore time at high SoC and battery temperature your battery will age poorly.

Nissan has screwed you in two ways:
1. By not having thermal control, your ability to mitigate temperature effects is limited
2. By not giving owners an easy way to charge to less than 100% SoC, most owners do not mitigate that effect.
2013 LEAF 'S' Model with QC & rear-view camera
Bought Jan 2017 from N. California
Two years in Colorado, now in NM
03/18: 58 Ahr, 28k miles
11/18: 56.16 Ahr, 30k miles
09/20: 54.3 Ahr; 38k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

lorenfb
Posts: 2474
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Leaf Number: 416635
Location: SoCal

Re: Conditioning Your Battery / Keeping as Healthy as Possible

Sun Nov 22, 2020 1:04 pm

SageBrush wrote:
Sun Nov 22, 2020 12:29 pm
I am not aware of ANY studies that can be used to quantify longevity differences between these cycle schedules
20 - 80
20 - 70
25 - 70
25 - 80
30 - 70
30 - 80
Check here for insight of what's been discussed prior on MNL; viewtopic.php?f=30&t=23606&p=525629&hil ... le#p525452

The link to the source can be found on MNL.
#1 Leaf SL MY 9/13: 76K miles, 47 Ahrs, 5.0 miles/kWh (average), Hx=70, SOH=73, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 10.3K miles, SOH 109Ahrs/115Ahrs, 5.2 miles/kWh (average), DOD > 20%, temp < 105F

fromAtoB
Posts: 6
Joined: Mon May 27, 2019 9:04 am
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Leaf Number: 311323
Location: Near Seattle

Re: Conditioning Your Battery / Keeping as Healthy as Possible

Mon Nov 23, 2020 7:07 am

SageBrush wrote:
Sun Nov 22, 2020 12:29 pm

Nissan has screwed you in two ways:
1. By not having thermal control, your ability to mitigate temperature effects is limited
2. By not giving owners an easy way to charge to less than 100% SoC, most owners do not mitigate that effect.
The first one I guess you are talking about liquid cooling not air cooling and/or other functions, although I’ve not looked into this so far. Fortunately we live in the Seattle area so our temperatures are moderate.


About this second, yes I seem to be finding that out after sitting, reading, and experimenting in my Leaf for a while last night.

- The Leaf has a timer but it’s simply for start and stop times, is meant for a standard daily cycle, and is based simply on time not charge.
- I downloaded the Nissan Connect app. It gets lots of one star reviews at the App Store and I could not connect to my vehicle in ten minutes of trying. But looking at the demo mode it seems to not support remote stopping of charging.
- The Leaf Spy app hasn’t been updated in two years so I’m hesitant to get it, but the description doesn’t seem to suggest you can start/stop charging with it.

So if I want to charge to some target not 100% then I’ll need to do a little mental math, plug it in, and then remember to walk out to my garage and unplug it at the right time.

Have I got that right?

And now I’m curious, do other EVs allow simple SOC management?
2015 Leaf, four year lease then returned.
2019 Leaf Plus, blue.

SageBrush
Posts: 5377
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Re: Conditioning Your Battery / Keeping as Healthy as Possible

Mon Nov 23, 2020 7:25 am

fromAtoB wrote:
Mon Nov 23, 2020 7:07 am

So if I want to charge to some target not 100% then I’ll need to do a little mental math, plug it in, and then remember to walk out to my garage and unplug it at the right time.

Have I got that right?
Some people talk about doing just that.
Others use an EVSE that has a timer;
Others add a timer to the EVSE (uncommon in the US)
Others set the time to end charging *later* (~ an hour for L2) than their planned departure time. I think this is the most elegant and simple, but people appear to have trouble with the implementation and it requires a reasonably consistent leave time. One way or another, Nissan did not make it straightforward. As I said above, the time spent at high SoC is important. I I think most people agree that it is considerably more important than the absolute SoC per se, so I suggest focusing on that parameter rather than agonizing over the occasional charge using L2 up to 100% SoC.

The forum is chock full of discussion that is LEAF specific
And now I’m curious, do other EVs allow simple SOC management?
Other EVs vary. Tesla is flexible and easy, and I've read that GM is too. I don't know other EVs to say.

---
LEAF has a reasonable reputation in the Seattle/PNW climate. You are fortunate
Last edited by SageBrush on Mon Nov 23, 2020 7:54 am, edited 2 times in total.
2013 LEAF 'S' Model with QC & rear-view camera
Bought Jan 2017 from N. California
Two years in Colorado, now in NM
03/18: 58 Ahr, 28k miles
11/18: 56.16 Ahr, 30k miles
09/20: 54.3 Ahr; 38k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

WetEV
Posts: 4055
Joined: Fri May 04, 2012 8:25 am
Delivery Date: 16 Feb 2014
Location: Near Seattle, WA

Re: Conditioning Your Battery / Keeping as Healthy as Possible

Mon Nov 23, 2020 7:47 am

fromAtoB wrote:
Mon Nov 23, 2020 7:07 am
SageBrush wrote:
Sun Nov 22, 2020 12:29 pm
Nissan has screwed you in two ways:
The first one I guess you are talking about liquid cooling not air cooling and/or other functions, although I’ve not looked into this so far. Fortunately we live in the Seattle area so our temperatures are moderate.
Sage is a Tesla Fanbouy. Expect hate for any other EV.

There are both advantages and disadvantages to liquid cooling. If your car is a daily driver and you live in a moderate or cool place (Seattle is cool), then you will very likely be happy with passive cooling.

Sport driving, long distances with frequent recharging and very hot places you would probably want liquid cooling. Tesla cars only come with liquid cooling, so expect Sage to foam about this.

fromAtoB wrote:
Mon Nov 23, 2020 7:07 am
About this second, yes I seem to be finding that out after sitting, reading, and experimenting in my Leaf for a while last night.

- The Leaf has a timer but it’s simply for start and stop times, is meant for a standard daily cycle, and is based simply on time not charge.
- I downloaded the Nissan Connect app. It gets lots of one star reviews at the App Store and I could not connect to my vehicle in ten minutes of trying. But looking at the demo mode it seems to not support remote stopping of charging.
- The Leaf Spy app hasn’t been updated in two years so I’m hesitant to get it, but the description doesn’t seem to suggest you can start/stop charging with it.
You can start but not stop charging with the Nissan app. LeafSpy is more instrumentation and tweeking.
fromAtoB wrote:
Mon Nov 23, 2020 7:07 am
So if I want to charge to some target not 100% then I’ll need to do a little mental math, plug it in, and then remember to walk out to my garage and unplug it at the right time.

Have I got that right?

And now I’m curious, do other EVs allow simple SOC management?
What fraction of the battery do you use every day? Example: If it was around 15%, you might set the timer to charge overnight by 20%. If above 60%, don't plug in. Should stay mostly between 45% and 80%, and while slightly better results would be possible, is still fairly good. One quick look, no math, plug in or not plug in, done.

About every other EV allows better simple SOC management. The eTron has a charge target from 50% to 100% by 10% steps, and I can set different targets at different locations. At home, is currently set for 70%, away from home is set to 100%. Bolt as well, other than older Bolts that had only "hill top mode" or a 90% limit. Even early Leafs allowed for 80% SOC limit...
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

fromAtoB
Posts: 6
Joined: Mon May 27, 2019 9:04 am
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Leaf Number: 311323
Location: Near Seattle

Re: Conditioning Your Battery / Keeping as Healthy as Possible

Mon Nov 23, 2020 9:33 am

WetEV wrote:
Mon Nov 23, 2020 7:47 am
fromAtoB wrote:
Mon Nov 23, 2020 7:07 am
SageBrush wrote:
Sun Nov 22, 2020 12:29 pm
Nissan has screwed you in two ways:
What fraction of the battery do you use every day? Example: If it was around 15%, you might set the timer to charge overnight by 20%. If above 60%, don't plug in. Should stay mostly between 45% and 80%,

That’s a good idea. That might work for us on weekends.

During weekdays - when the governor here isn’t closing the economy down - we need to make three round trips of about 55 miles each day totaling 165 mi The last one we arrive home nearly 9 pm. The joys of parenthood! That might change next Summer or Fall but such is our sentence for now. For that I love love love the range of our Plus. We couldn’t have done this with our nice 2015 Leaf, and gas would cost us a fortune.

For those busy days, I might try to start the morning at 80%, and then put in one charging session during the day plus one at night.

The easier strategy could be to estimate a timer for 165 miles and then plug it in at 9 pm arrival and then let it go for maybe 6 hours. 165 miles would be about 75% of our vehicles GOM range as we drive. Now I’m not sure whether high SOC or low SOC is more harmful. I could time it to 100% right before we leave and have about 25% left when the day is done, or shoot for 90% and have 15% left when the day is done.
2015 Leaf, four year lease then returned.
2019 Leaf Plus, blue.

WetEV
Posts: 4055
Joined: Fri May 04, 2012 8:25 am
Delivery Date: 16 Feb 2014
Location: Near Seattle, WA

Re: Conditioning Your Battery / Keeping as Healthy as Possible

Mon Nov 23, 2020 11:20 am

fromAtoB wrote:
Mon Nov 23, 2020 9:33 am
That’s a good idea. That might work for us on weekends.

During weekdays - when the governor here isn’t closing the economy down - we need to make three round trips of about 55 miles each day totaling 165 mi The last one we arrive home nearly 9 pm. The joys of parenthood! That might change next Summer or Fall but such is our sentence for now. For that I love love love the range of our Plus. We couldn’t have done this with our nice 2015 Leaf, and gas would cost us a fortune.

For those busy days, I might try to start the morning at 80%, and then put in one charging session during the day plus one at night.

The easier strategy could be to estimate a timer for 165 miles and then plug it in at 9 pm arrival and then let it go for maybe 6 hours. 165 miles would be about 75% of our vehicles GOM range as we drive. Now I’m not sure whether high SOC or low SOC is more harmful. I could time it to 100% right before we leave and have about 25% left when the day is done, or shoot for 90% and have 15% left when the day is done.
High SOC increases calendar loss and cycling loss. Low SOC increases cycling loss.

Don't leave the battery at high SOCs for long periods of time, and make cycles as narrow as possible for best battery life...

So your daily trips are about 25% of the battery. If you only charge overnight, and your schedule is predictable, charge to 100% at departure time. This avoids time at high SOCs as you don't leave the car for long at high SOC, and avoids low SOCs. 100% to 75% is much better for the battery than 80% to 5%. A single charge overnight would likely not work in winter, as efficiency reduces at lower temperatures, more energy is used for climate control, etc.

Depending on the time between trips and where the car is parked, you might plug in multiple times during the day. Hard to analyze.
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

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