jmurtagh13
Active member
SageBrush said:
I know the type is small and hard to read, but it's down to 103.43, not 101.43. Still not great. 99% of the time i only change to 70% but it is Atlanta and it is hot here.
The 40KWH Battery Topic
- Thread starter LeftieBiker
- Start date
Help Support My Nissan Leaf Forum:
I know the type is small and hard to read, but it's down to 103.43, not 101.43. Still not great. 99% of the time i only change to 70% but it is Atlanta and it is hot here.
Jollermd
Member
SageBrush said:
I may be playing devils advocate here:
However this statement above concerns me. I have always run my battery as low as possible (not enough charge for the next day) and then charged, with the assumption it was good for the battery to have less but deeper charges. fallacy?
And I want to thank you for all your comments.
Nick
Sagebrush lives in the mountains of Colorado, IIRC, and his climate is generally favorable for keeping the car at 80% charge. I wouldn't suggest doing it under all circumstances, though.
goldbrick
Well-known member
Jollermd said:
I don't know of any professional Li battery engineers here on the forum but from what I've read, the things that age a battery are (in no particular order) time, heat, very low and very high % SOC. I don't think there would be much difference between charging from 20% to 80% half as often as charging from 35% to 65% but that is just my guess. I've heard that keeping the battery close to 50% SOC is ideal but I think the real damage occurs at the extremes and there probably isn't much difference in aging when the car sits at 40% vs 60%.
One thing to keep in mind is that charging generates heat. It may be the case that several small charges will heat the battery less than one longer charge. Otherwise, I'd just try to avoid high SOC in combination with high temperature. Also, high charge currents (eg CHAdeMO) at low temperatures are supposed to be damaging so it's probably best to avoid those as well. All just IMHO.
Your charging behavior from a low-ish SoC is fine. Our LEAF does not live at 80% or anywhere near because it is a 24 kWh model with limited range. SoC mostly ranges from 80 <-> 40 with a focus on minimizing the time at 80% in hot weather. I don't care if the SoC is 80% if it is 30- F ambient, and I like the idea of not charging the car when the battery is cold to minimize battery plating.Jollermd said:
By the way, my *Tesla* charging routine is similar to yours. It is done that way for calibration reasons, not degradation reasons.
DaveinOlyWA
Well-known member
Jollermd said:
As EVs grow in popularity, more and more versions of batteries with somewhat different properties, emerge with Lithium being one of the few common characteristics but thru it all it has been proven over and over that more frequent, shallower cycling, is the best for longevity.
Now we have to take that tidbit and make it work in a car. Its easy to do it on a cellphone, not so much on a car. So you want enough to cover your needs which may include any or all of the following;
Basic commute
weather adjustment
common detours
anti stress range
Either way; if you drive every day whether it be a little or a lot but don't charge every day then you are overcharging. Living in the middle implies being super low is just as bad as being super high on the SOC scale but not sure I am accepting that.
So yeah, charging to 60% SOC and running it down to 40% and recharging WILL make your pack last the longest but can your sanity last that long?
But if you are like most of us; your car has more range than you normally use.goldbrick
Well-known member
There is also the issue of 'bang for the buck' to consider. If I can get 95% of the life out of the battery for 25% of the stress level on how/when to charge that seems like a good bargain.
Everyone's situation is different but I like my Leaf a lot more now that I just accept that battery degradation (aging) is a fact of life and not stress out on it too much. I'm still careful to avoid the really dumb things (eg, 100% SOC all day in the hot summer sun) but otherwise I'm just driving it and charging it when needed. From 20ish % to 80ish% most of the time but sometimes less, sometimes more since it's too hard to get it exact all the time.
Everyone's situation is different but I like my Leaf a lot more now that I just accept that battery degradation (aging) is a fact of life and not stress out on it too much. I'm still careful to avoid the really dumb things (eg, 100% SOC all day in the hot summer sun) but otherwise I'm just driving it and charging it when needed. From 20ish % to 80ish% most of the time but sometimes less, sometimes more since it's too hard to get it exact all the time.
GaleHawkins
Well-known member
Our 2016 Leaf SL got a new 40 kWh February 2020. SOH was 99.87 at install. Rate degradation was .01+% daily for first 6 months and had slowed to about .01% every 3 days and was down to 96.07% when it was totaled 15 days ago due to a teenager running a red light.
2 hours ago ran SLP again SOC and SOH readings were unchanged to my surprise. About a week ago I drove it about one 1/10th of a mile and backed it onto our tilt trailer and brought it home.
This Wednesday we plan to clean out a bay to get it into the shop so we can strip the front cap and all parts forward of the motor.
I ran SLP a second time to double check the readings but I could tell by the low battery temperature it was today's reading.
We have not yet bought the parts car.
2 hours ago ran SLP again SOC and SOH readings were unchanged to my surprise. About a week ago I drove it about one 1/10th of a mile and backed it onto our tilt trailer and brought it home.
This Wednesday we plan to clean out a bay to get it into the shop so we can strip the front cap and all parts forward of the motor.
I ran SLP a second time to double check the readings but I could tell by the low battery temperature it was today's reading.
We have not yet bought the parts car.
I just moved several posts here from a duplicate topic.
danrjones
Well-known member
I'm approaching my next 3 month "update". Current stats are:
SOH: 90.05
AMPHr: 103.95
Hx: 104.00
Per my previous posts, my Hx continue to decline. It peaked at 109.17 in June.
And (likely) due to the temp now being cool, the daily adjustment have basically stopped.
I have been at 90.05 SOH since early November.
SOH: 90.05
AMPHr: 103.95
Hx: 104.00
Per my previous posts, my Hx continue to decline. It peaked at 109.17 in June.
And (likely) due to the temp now being cool, the daily adjustment have basically stopped.
I have been at 90.05 SOH since early November.
DougWantsALeaf
Well-known member
Dan
How many miles total and since last update? Many dc charges?
How many miles total and since last update? Many dc charges?
DaveinOlyWA
Well-known member
danrjones said:
I am tracking the relationship of Hx to rate of degradation. I hadn't noticed the temperature relationship. I got mine in November so could be the "new pack" factor but my Hx rose thru out the entire Winter. In Summer it fluctuated a bit seemingly rising on DC charge sessions more often than not. It has been on the decline for two months now and I am expecting a zero adjustment or maybe even a small bump up...
danrjones
Well-known member
DougWantsALeaf said:
I did two very small quick chargers to test a new fast charger in Inyokern but really they aren't much other than adding to the QC total.
Leafspy shows just over 7830 miles and 9 QC and 380 L1/L2s.
I never put a lot of miles on it, its an around town vehicle.
As to temp relationship, I personally believe the "daily" SOH adjustments are related to temperature. During our summer I will see 0.01 every day chipped away, sometimes 0.02. During the winter it all but stops. Not absolute proof of a relationship but it seems likely to me.
Maybe some form of automated SOH adjustment based on temp, and then the 3 month adjustment fixes that daily estimated range loss by either taking or giving SOH back. Remember, this is just a guess.
The Gen I Leaf does the same thing - it shuts down battery health readings in Winter. I suspect that it's because the BMS can't accurately report this information when the pack is cold.
DaveinOlyWA
Well-known member
danrjones said:
Agreed with "SOH" and temperature and also the reason I am tracking Hx. First Winter, SOH slows to reduction every 3-4 days but Hx is high; over 120. Jan adjustment is big, 1.5%. Then right towards end of quarter before April adjustment, Hx starts to fall and SOH reduction changes to every 4-8 days, April adjustment; just under 1% drop. Hx continues slow decline to just under 117 and July adjustment goes up 1.12%
Now daily adjustments are holding steady anon my work week (4 days) short commute 27 miles RT verses longer day off travel when I would see a drop almost always .02% although I had a handful of times I traveled over 80 miles (under 100) with no change and this pattern runs until I trade up in Nov with Oct adjustment of zero. In fact, my estimated Oct adjustment window saw a streak of 10 days with no change.
Strangely, the last 3 weeks before trading, my Hx starts wandering up again. Was in high 114's and gets to low 117's by trade date but daily changes holding at slightly longer intervals (5-8 days) than first winter.
So I feel that Hx is telling us something but still unsure of what it is.
danrjones
Well-known member
The only evidence I have in regards to HX, and its very anecdotal, is that it relates to SOC
When I charged to higher SOC hx seemed to start going up. I used to routinely charge to 80 to 85% plus occasionally 100%, but early last summer changed that to about 70% with no 100% charges. Since then my hx has been going down.
When I charged to higher SOC hx seemed to start going up. I used to routinely charge to 80 to 85% plus occasionally 100%, but early last summer changed that to about 70% with no 100% charges. Since then my hx has been going down.
danrjones
Well-known member
Per my last, the more I look through my data, the more HX seems connected to my SOC.
As an example, over the weekend my SOC was sitting right at 70% Saturday through this morning. No Change in HX.
Looking through data, my HX seems to go up whenever i have charged above about 78%. It REALLY went up anytime I charged above 90% or to 100%. Letting the battery sit at high SOC seems to be the worst, and HX would continue to rise for some time after that event.
Letting your car sit at SOC between about 40% and 70% seems to be the ticket for HX dropping.
Anecdotal evidence but it is what I see looking through my data.
My last big rise in HX was Feb to April of this year, where my HX went from 106 to over 109.
What was i doing during this time? I was hiking close to home, which meant I could use my Leaf.
But I was having to charge it to 90 to 100% to make the trips.
Come may it gets too hot, and I was hiking further away, using my other vehicles.
At that point I started only charging to ~70% for work and around town driving.
But I don't charge every night, I let it drop to around 30% (about every 3-4 days).
So the battery gets a good amount of time right in the middle of the pack for SOC.
As an example, over the weekend my SOC was sitting right at 70% Saturday through this morning. No Change in HX.
Looking through data, my HX seems to go up whenever i have charged above about 78%. It REALLY went up anytime I charged above 90% or to 100%. Letting the battery sit at high SOC seems to be the worst, and HX would continue to rise for some time after that event.
Letting your car sit at SOC between about 40% and 70% seems to be the ticket for HX dropping.
Anecdotal evidence but it is what I see looking through my data.
My last big rise in HX was Feb to April of this year, where my HX went from 106 to over 109.
What was i doing during this time? I was hiking close to home, which meant I could use my Leaf.
But I was having to charge it to 90 to 100% to make the trips.
Come may it gets too hot, and I was hiking further away, using my other vehicles.
At that point I started only charging to ~70% for work and around town driving.
But I don't charge every night, I let it drop to around 30% (about every 3-4 days).
So the battery gets a good amount of time right in the middle of the pack for SOC.
DougWantsALeaf
Well-known member
Here are my Leaf stats for my 2 Leafs. Both 62s, but I can't figure the Hx.
https://docs.google.com/spreadsheets/d/1mjGg2SdFQzo3_GzA6YY_Ob1MrfkX9hidN2caTR92xAA/edit?usp=drivesdk
https://docs.google.com/spreadsheets/d/1mjGg2SdFQzo3_GzA6YY_Ob1MrfkX9hidN2caTR92xAA/edit?usp=drivesdk
Similar threads
Latest posts
-
-
-
-
-
The battery replacement/buyback thread.
- Latest: wrldsgrtstmiracle
-
-