Yikes, degradation is looking bad (2018 Leaf)

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DaveinOlyWA said:
NavyCuda said:
DaveinOlyWA said:
Charging to full to balance cells is not needed.

This is bad advice. Balancing of cells is cruical to the long term lifespan of any multicell battery.

This is true and the reason why cells are balancing all the time. The benefit of top end balancing is for maximum range but it heavily outweighed by the risk of greater degradation

Depends on use case. I’m pushing my battery much harder now than I did previously. I used to draw down to ~50% and fully charge on both ends of my trip, balancing twice a day. Now I draw down to 10-25% SOC, L1 to ~85%, draw down to 10-20% again then fully charge when I get home.

As I sit here at the quick charger, I have 98,156km and 12/12bars. 2015 SV I bought new off the lot. ~8weeks until my 2018 arrives!
 
Trying to only charge to 80% everyday, which is a manual process since Nissan didn't include that feature) and then seeing degradation anyhow makes it not worth the effort. I'm just going to charge to 100% and let them deal with the warranty battery swap if it comes to that.
 
tuningin said:
Trying to only charge to 80% everyday, which is a manual process since Nissan didn't include that feature) and then seeing degradation anyhow makes it not worth the effort. I'm just going to charge to 100% and let them deal with the warranty battery swap if it comes to that.

Charging to 80% is only ideal for long term storage. Only charging to 80% and not balancing the cells will negatively effect the lifespan of the battery.
 
NavyCuda said:
tuningin said:
Trying to only charge to 80% everyday, which is a manual process since Nissan didn't include that feature) and then seeing degradation anyhow makes it not worth the effort. I'm just going to charge to 100% and let them deal with the warranty battery swap if it comes to that.

Charging to 80% is only ideal for long term storage. Only charging to 80% and not balancing the cells will negatively effect the lifespan of the battery.

I wouldn't agree that there is a consensus on this. Charging from to 100% heats up the packs. Heat=bad for battery longevity. This is based on whitepaper studies on Lithium Ion batteries. But I'm sure that there are always exceptions and these studies are now a decade old so maybe chemistry has helped.
 
tuningin said:
NavyCuda said:
tuningin said:
Trying to only charge to 80% everyday, which is a manual process since Nissan didn't include that feature) and then seeing degradation anyhow makes it not worth the effort. I'm just going to charge to 100% and let them deal with the warranty battery swap if it comes to that.

Charging to 80% is only ideal for long term storage. Only charging to 80% and not balancing the cells will negatively effect the lifespan of the battery.

I wouldn't agree that there is a consensus on this. Charging from to 100% heats up the packs. Heat=bad for battery longevity. This is based on whitepaper studies on Lithium Ion batteries. But I'm sure that there are always exceptions and these studies are now a decade old so maybe chemistry has helped.

+1 on that. Long term storage recommendation is actually around 40% SOC. Top end balance likely increases range but no more than a few miles at most but the reality is the chemistry Nissan uses is simply not robust enough to handle warmth (not hot...just warm is enough) or high SOC.
 
Why charge to 100% all the time, gambling that it does no harm, if you don't need the range on a daily basis? Sure, occasional charges to 100% make sense, but those don't have to be very frequent and one can choose to do those when it's not hot out and when you know you can drive the car right after it stops charging...

I have my 2013's charge timer set to charge to 100% every Sunday morning, because I know it will be cooler overnight and that my wife will be going to church right after the charging timer ends (so no worries about it sitting idle with a high SOC). Most other nights, I charge to 80%, but I have the override set to charge to 100% for those times when I public charge and want the extra boost.
 
alozzy said:
Why charge to 100% all the time, gambling that it does no harm, if you don't need the range on a daily basis? Sure, occasional charges to 100% make sense, but those don't have to be very frequent and one can choose to do those when it's not hot out and when you know you can drive the car right after it stops charging...

I have my 2013's charge timer set to charge to 100% every Sunday morning, because I know it will be cooler overnight and that my wife will be going to church right after the charging timer ends (so no worries about it sitting idle with a high SOC). Most other nights, I charge to 80%, but I have the override set to charge to 100% for those times when I public charge and want the extra boost.

This may seem strange but I know people who charge to 100% every 3 to 5 days because its easier than setting a timer to charge 2 hours a day...
 
DaveinOlyWA said:
alozzy said:
Why charge to 100% all the time, gambling that it does no harm, if you don't need the range on a daily basis? Sure, occasional charges to 100% make sense, but those don't have to be very frequent and one can choose to do those when it's not hot out and when you know you can drive the car right after it stops charging...

I have my 2013's charge timer set to charge to 100% every Sunday morning, because I know it will be cooler overnight and that my wife will be going to church right after the charging timer ends (so no worries about it sitting idle with a high SOC). Most other nights, I charge to 80%, but I have the override set to charge to 100% for those times when I public charge and want the extra boost.

This may seem strange but I know people who charge to 100% every 3 to 5 days because its easier than setting a timer to charge 2 hours a day...

I use about 55% of the range per day/ per charge. There is a reason I'm already at 4500 miles after a few months of ownership ;)

I charge at work so you can imagine that it becomes a bit bothersome to try to set a timer and then step out of meetings and across our campus. We do use the Juicebox that where I can log in and set a maximum charge amount by kwh, but for some reason after a couple of hours, it begins charging again if I don't unplug.
 
alozzy said:
Why charge to 100% all the time, gambling that it does no harm, if you don't need the range on a daily basis? Sure, occasional charges to 100% make sense, but those don't have to be very frequent and one can choose to do those when it's not hot out and when you know you can drive the car right after it stops charging...

I have my 2013's charge timer set to charge to 100% every Sunday morning, because I know it will be cooler overnight and that my wife will be going to church right after the charging timer ends (so no worries about it sitting idle with a high SOC). Most other nights, I charge to 80%, but I have the override set to charge to 100% for those times when I public charge and want the extra boost.

Not charging to 100% frequently will accelerate degradation. That’s a fact of the nature of batteries in general. 98,000+ km reinforces the fact that the battery likes being balanced on a regular basis. When my Leaf was brand new it would take ~3.5 hours to fully charge with balancing from 40-50%. After about 6 months it dropped to ~2.5 hours. That was getting fully charged twice a day.
 
Each person's use case is a little different, there isn't really a norm. So all I'm really saying is limit the frequency of 100% charges and try not to charge to 100% SOC when it's hot out - both of which will go a long way to keeping the LEAF's battery pack healthy. Of course there will be times when neither is possible but on the flip side, sticking to a routine of 100% SOC charge all the time is almost a guarantee that your battery will suffer from premature degradation.
 
alozzy said:
Each person's use case is a little different, there isn't really a norm. So all I'm really saying is limit the frequency of 100% charges and try not to charge to 100% SOC when it's hot out - both of which will go a long way to keeping the LEAF's battery pack healthy. Of course there will be times when neither is possible but on the flip side, sticking to a routine of 100% SOC charge all the time is almost a guarantee that your battery will suffer from premature degradation.

You are wrong.

I always charge my leaf to 100%. Even after a short run to the garbage dump. That’s almost 3 years of charging to 100% everyday the car gets used.
 
NavyCuda said:
alozzy said:
Each person's use case is a little different, there isn't really a norm. So all I'm really saying is limit the frequency of 100% charges and try not to charge to 100% SOC when it's hot out - both of which will go a long way to keeping the LEAF's battery pack healthy. Of course there will be times when neither is possible but on the flip side, sticking to a routine of 100% SOC charge all the time is almost a guarantee that your battery will suffer from premature degradation.

You are wrong.

I always charge my leaf to 100%. Even after a short run to the garbage dump. That’s almost 3 years of charging to 100% everyday the car gets used.


Ditto. 100% last three years. No leaf spy data but 2015 S 41K and still 12 bars.
 
@NavyCuda Looking at some of your old posts, you live in Canada. That's likely why you've seen little impact with charging to 100% all the time. Also, as I mentioned, charging to 100% when it's not hot out and then driving the LEAF shortly thereafter won't hurt the battery. Heat is the enemy of the battery pack.

@Foschas seems to live in Kingston, MA which isn't a hot climate either.

Someone in Texas or Arizona and charging to 100% SOC all the time will not be so lucky, particularly if they charge when it's hot out or park the car in the heat with a high SOC. No battery chemistry tweaks are going to fix that. Just look at 30 kWh battery pack degradation issues for confirmation of that.

http://batteryuniversity.com/learn/article/bu_808b_what_causes_li_ion_to_die

The manganese-based Li-ion batteries chosen for the Nissan Leaf and other EVs have excellent lab results. What may have been overlooked in the Nissan Leaf test is the damage that is being done when keeping the battery at high voltage and elevated temperature. As the coulombic efficiency tests reveal, these two conditions can cause more damage than cycling

https://www.vehicular.isy.liu.se/Publications/MSc/16_EX_5015_OJ.pdf

The main conclusion that can be drawn regarding degradation is that temperature is the most influencing factor in cycle ageing as well as calendar ageing. The temperature of cells will be dependant on ambient temperature and current. State of charge level will also influence the degradation, but generally to a lesser extent than temperature. It is better to store a lithium-ion battery with a low state of charge rather than a high level. If possible it also good to keep the state of charge low at usage with small deviations. This may not be possible for all applications, especially not for BEVs as it will impede range
 
Foschas said:
Ditto. 100% last three years. No leaf spy data but 2015 S 41K and still 12 bars.
"No leaf spy data" means you don't know how much degradation you have, since 12 bars can still have significant loss.

I usually charge my 4 year old 2013 to 100%, 4 days a week (during the day, in a parking garage). While it is still at 12 bars, it has just about 14% loss.
http://myevstats.com/index.php?sVIN=424487
 
Why are 2015ers chiming in with VERY VERY bad advice? (Maybe a glance at the thread title is in order) Charging to 100% is bad for ALL Lithium chemistries. It has nothing to do with heat. Its all about voltage and the breakdown that occurs with sustaining the voltage on the edge for extended periods of time.

So you got a 2015 W/O LEAF Spy and the only thing you can claim is you haven't lost a bar AKA at least 15+% capacity? That is hardly "good" in any way. I have NEVER lost a bar over 4 different versions of the LEAF driving MUCH farther and guess what? Other than my much maligned 2016 S 30, the packs have exhibited unacceptably high degradation which is why I don't have them anymore. The 2018 is still being evaluated but has the likely potential of having 2015 like degradation and still be acceptable simply because it has a LOT TO LOSE. Your 2015's don't.
 
Perhaps this has been covered but, I notice my 2018 only shows 96% in LeafSpy when it shows 100% on the dash. I would guess that if it is common knowledge that charging to 100% is detrimental to the battery pack, Nissan knows it as well. Therefore, with battery degradation/warranty concerns, Nissan, in order to give the owner the satisfaction/confidence that his/her battery is "FULL", the dash shows 100% when it is actually a few "volts" short. Everyone wins! :lol:

Ed
 
edorfox said:
Perhaps this has been covered but, I notice my 2018 only shows 96% in LeafSpy when it shows 100% on the dash. I would guess that if it is common knowledge that charging to 100% is detrimental to the battery pack, Nissan knows it as well. Therefore, with battery degradation/warranty concerns, Nissan, in order to give the owner the satisfaction/confidence that his/her battery is "FULL", the dash shows 100% when it is actually a few "volts" short. Everyone wins! :lol:

Ed

Unfortunately the previous Leafs also showed a higher than actual SOC, but it wasn't enough of a buffer.
 
DaveinOlyWA said:
Why are 2015ers chiming in with VERY VERY bad advice? (Maybe a glance at the thread title is in order) Charging to 100% is bad for ALL Lithium chemistries. It has nothing to do with heat. Its all about voltage and the breakdown that occurs with sustaining the voltage on the edge for extended periods of time.

So you got a 2015 W/O LEAF Spy and the only thing you can claim is you haven't lost a bar AKA at least 15+% capacity? That is hardly "good" in any way. I have NEVER lost a bar over 4 different versions of the LEAF driving MUCH farther and guess what? Other than my much maligned 2016 S 30, the packs have exhibited unacceptably high degradation which is why I don't have them anymore. The 2018 is still being evaluated but has the likely potential of having 2015 like degradation and still be acceptable simply because it has a LOT TO LOSE. Your 2015's don't.

Wrong.

All battery chemistries, lead acid, nicad, li-ion, li-polymer, etc, benifit from the cells being properly balanced. If anything the hardest things on the batteries are not balancing and not charging frequently enough. Those of you going to extremes to try and save your batteries are reducing their lifespan and then use those bad datapoints to further your erroreous theory.

The only major difference is that li-ion doesn’t need a maintenance charge and prolonged storage at 100% state of charge is not ideal.
 
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