ironmanco
Well-known member
LeftieBiker said:
Can someone point me to the exact details of the protocol - I'd consider trying it.
2016-2017 model year 30 kWh bar losers and capacity losses
- Thread starter cwerdna
- Start date
Help Support My Nissan Leaf Forum:
Can someone point me to the exact details of the protocol - I'd consider trying it.
TheLostPetrol
Well-known member
Edit: deleted
TheLostPetrol
Well-known member
LeftieBiker said:
While this tactic reportedly increases the SOH (and AHr) reported by the BMS, I haven't seen any post claim that it increases range. AFAIK, only one poster (a man from Sweden, right?) measured range (i.e. change in SOC for a standard trip) in two LEAFs. He found the aggressively driven one's SOH was 10% too high and the timidly driven one's SOH was 10% too low.
I'm not sure where the info is either. I don't dismiss it, but do take it with a grain of salt.
arnis
Well-known member
Anything that ends up with warranty replacement is faster than rapid.SageBrush said:
It's defective (defective batteries can either die unexpectedly or degrade rapidly).
Except if not used according to requirements (Leaf manual does state cold limit, but not specific hot limit,
therefore, wherever vehicle is sold, any regular temperature upper end in that area is considered acceptable).
Rapid degradation should be one that ends up with less than 80% of capacity in short period of 5 years (normal mileage).
It's very common in many areas to use 20:80 ratio, incl batteries. Nissan's 4th bar is their vague BS warranty limit.
Batteries, that keep at least 80% for 5 years, can be counted in "expected degradation" box. For now.
Batteries, that keep at least 80% for vehicle lifetime (minimum 10, maximum 20 years according to 2013 vehicle lifetime statistics, though no less than 160 000km) can be called lifetime batteries.
As of right now. Most Tesla's appear to have lifetime battery. Leafs have either defective, rapidly degrading or normally degrading batteries.
After Lizard upgrade there was some improvement, but far from normal in terms of worldwide sales.
80% limit is not the end. It's just industry accepted benchmark. To simplify, above that and battery is "used". Below that and battery is degraded (any preposition like: slightly, somewhat, moderately, heavily etc suits here too).
EDIT: warranty is usually about expected range not capacity. Some manufacturers use buffer zones.
It's possible to lose 30% of capacity but only 10% of range compared to new vehicle.
PS: Lifetimes and mileages are suitable for private passenger vehicles. Not commercial, heavy, taxi etc.
Legislators have not yet fully understood pollution of EVs. For example, ICE vehicles can't go worse than their pollution tier/class.
If it does, it doesn't pass MOT (in theory, corruption doesn't count here, either local, or something bigger, VW for example)
If EV can't regen nominally (Leaf khmkhm) it means vehicle efficiency is below expected (friction brakes used, more energy consumed etc). There are no rules. Yet. Vehicle production has a carbon footprint. Replacing batteries again and again makes it bigger. Manufacturers
might be tempted to use cheaper stuff in the name of profits and sacrificing real footprint compared to what's on the paper.
Therefore, in not so far future, when EVs/hybrids are the majority of new vehicles sold, things will be stricter.
PS: There are already hybrids (Civic, Prius) that have failed batteries "fixed". Honda did some "software" tweak that deleted the check-light on the dash so vehicle could pass MOT and warranty terms. But vehicle's fuel efficiency (emission tiers) due to dead battery were wrong. No problems. Yet.
It's just a matter of time. Due to lots of PHEV's coming in near future, I believe the snowball will start rolling from there.
First thousands of complaints from owners who can't get their promised electric range (crucial 80% from promised 20-50km) out of their short electric range PHEV vehicles within warranty period (5-years, 100 000km).
Chevy Volt has all that sorted out. It has massive upper-lower SOC limiters, that, AFAIK, expand during battery degradation to counteract lost range. Excellent example that all that can be sorted out reasonably. Otherwise, manufacturers will be tempted to do what smartphone industry does. My Samsung has charging limit set to 4.4V Excellent data on paper. Lost 30% of capacity within first year. And 20% more during second year. Cars have minimum lifetime of 160 000km or 8 years. Absolute minimum! ICEV, HEV, PHEV, RExEV, EV, whatever. Smartphones have minimum lifetime of 2 years. Even though things are mad in phone and HEV zone I believe it will not continue with real stuff (actual/meaningful EV range).
I'm pretty serious about that - hope it inspires some important people that might not have been informed yet :ugeek:
Yes. I've also done that also many times. Rapid power flow triggers that often. Either long QC charge with warm battery or full speed driving for few minutes (literally, max speed). It's temporary, a week/month. Actual capacity doesn't change. GOM maximum range will. It doesn't matter. Except when you try to sell your vehicle.
Here is another one: If keeping SOC below 80% wouldn't have any benefits at all, Tesla's would not have a slider capable going down to 50%.
DaveinOlyWA
Well-known member
sflores91 said:
YOU are the most important post in this entire thread!!!
too bad it wasn't June though. Probably gonna have to wait 5-6 months to find out if your replacement is any better. You MUST KEEP US UPDATED on your packs health...
DaveinOlyWA
Well-known member
LeftieBiker said:
multiple fast charges yes, but aggressive driving isn't really necessary. I will say that I am a law breaker regularly now that I have 30 kwh but pack manipulation was just as effective on 24 kwh packs when I made it a habit of never exceeding 62 mph.
Another thing that seems plausible is BMS simply losing track of the Health and several relatively deep discharges to at least 25-30% and complete recharges seems to bring numbers up on level 2. Its almost like a reset of sorts. This process takes longer but usually see results in no more than 4 days or so
DaveinOlyWA
Well-known member
SageBrush said:
What is the logic of a 50% recharge for trip planning?
arnis
Well-known member
Tesla's choice is one of the best. Nissan's choice was not.
Even though this slide wasn't exactly about voltage cells kept at, it gives the idea.
https://cdn.shopify.com/s/files/1/0674/3651/files/graph-18-battery-chemistry-comparison.jpg?17426464464965184610
Nissan's official recommendation is 80% anywhere EPA didn't intervene.
Also EPA intervention is questionable (what about Tesla's slider, what EPA did with Model S range? which percent was chosen?)
Leaf literally has a tick box Battery Long Life Mode. There are PEOPLE (at dealers for example)
saying a lot of things. But they are nobody in terms of information value.
But that button was made by people who made the car.
Tesla gives an option to choose whatever between 50% and 90%. Jeff told us (and showed data) to choose the low end. End of story.
Can't extrapolate in any way that this doesn't apply to chemistry that degrades faster.
Liquid cooling loop has little to do with shelf life actually (time when vehicle is not used). Tesla hardly cools the battery.
Chemistry is often between 35-50C. No active cooling.
Conclusion: according to what we know, Leaf is not less sensitive to higher SOC degradation compared to Tesla.
Recommendation to charge closer to 50% was not Tesla specific.
And it was given by a person whose information is more valuable/grounded than our opinions combined.
Tesla's slider clearly states "Daily". SC has nothing to do with daily usage scenario.
Even though this slide wasn't exactly about voltage cells kept at, it gives the idea.
https://cdn.shopify.com/s/files/1/0674/3651/files/graph-18-battery-chemistry-comparison.jpg?17426464464965184610
Nissan's official recommendation is 80% anywhere EPA didn't intervene.
Also EPA intervention is questionable (what about Tesla's slider, what EPA did with Model S range? which percent was chosen?)
Leaf literally has a tick box Battery Long Life Mode. There are PEOPLE (at dealers for example)
saying a lot of things. But they are nobody in terms of information value.
But that button was made by people who made the car.
Tesla gives an option to choose whatever between 50% and 90%. Jeff told us (and showed data) to choose the low end. End of story.
Can't extrapolate in any way that this doesn't apply to chemistry that degrades faster.
Liquid cooling loop has little to do with shelf life actually (time when vehicle is not used). Tesla hardly cools the battery.
Chemistry is often between 35-50C. No active cooling.
Conclusion: according to what we know, Leaf is not less sensitive to higher SOC degradation compared to Tesla.
Recommendation to charge closer to 50% was not Tesla specific.
And it was given by a person whose information is more valuable/grounded than our opinions combined.
Tesla's slider clearly states "Daily". SC has nothing to do with daily usage scenario.
The default recommendation on the Tesla slider for daily charging is ~ 85 -- 90%
Back in the days when Tesla did not have a slider, owners picked 93% for daily charging and 100% for pre-trip.
It's true that the slider also served to circumvent the EPA rules that affected the Monroney range sticker but I'm trying to not add to the confusion here. The routine use of the slider by most owners is during Supercharger hopping to optimize charging times.
As for Jeff Dahn, when asked this year by a Tesla owner what practice would be ideal for battery longevity he responded 70% for daily charging and 100% for trips. 70% SoC in a LEAF is about 4v
https://www.youtube.com/watch?v=H1GffKahtwA
3:16 into the video
Back in the days when Tesla did not have a slider, owners picked 93% for daily charging and 100% for pre-trip.
It's true that the slider also served to circumvent the EPA rules that affected the Monroney range sticker but I'm trying to not add to the confusion here. The routine use of the slider by most owners is during Supercharger hopping to optimize charging times.
As for Jeff Dahn, when asked this year by a Tesla owner what practice would be ideal for battery longevity he responded 70% for daily charging and 100% for trips. 70% SoC in a LEAF is about 4v
https://www.youtube.com/watch?v=H1GffKahtwA
3:16 into the video
LTLFTcomposite
Well-known member
Will be interesting to see if failures with FWD and pop out door handles or whatever will have him tearing his hair out long before the battery gives out, let alone anywhere near 20 years.
arnis said:
Where's the factual basis for concluding this? That recommendation was totally based on the Tesla, i.e. your inferences don't count.
If you have any explicit statements where that recommendation applies to any Li ion EV battery, i.e. specifically to the Leaf,
then please provide it!
Besides, each EV's BMS can be designed/programmed to evaluate 100% SOC at different cell voltage levels based on that battery's
chemistry or any other parameter, thereby indicating 100% SOC but actually only allowing a value less than 100%.
GrowingTuna
New member
- Joined
- May 30, 2017
- Messages
- 3
New poster (hey everyone!), but have been lurking for a while. Been really enjoying this thread, so feel obligated to add my data as additional fodder for research/discussion.
Picked up 2017 30 KWh Leaf on 07/2017. Live in SoCal (LA county). SOH was 100% when picked up. Stayed at 100% for about a month. Currently at 91% SOH, AHr 72.53, after 4 months of driving. Odometer reading at 3600. 80 QC, 99 L1/L2s. Many of those L1/L2s were done at the dealer (See below).
Needless to say, there is some pretty serious degradation already given the date of acquisition and mileage, but looks like this isn't an outlier. As has already been observed, age + mileage seem to be a secondary factor regarding degredation. This is a lease, so I'm not torn up over the fact.
Some interesting tidbits I've picked up thus far that may help the community:
1. The car was sitting on the lot for at least a few months before I leased it. When I picked up the car, it already had ~60 L1/L2 charges, with less than 200 miles on the odometer. I saw the dealer plug in the car after my 2 mile test drive (which started at full battery); I believe they always kept it at 100%. The car was not kept under shade at the dealer. Despite that, the car was at a very healthy 100% SOH and 80.6 AHr When I picked it up.
2. I follow the generally accepted guidelines for battery longevity -- as much as I can in the SoCal climate. Charging to ~80%, keeping battery above 20%, and (trying to) keep the battery as cool as possible. Most of my charging was to regain 25-50% of the battery. For the summer months, temp bars were almost always at 6; during the quick charges (which I kept <10 minutes), bars often hit 7 or 8. A couple of times I hit 9 temp bars, but immediately unplugged. Almost all QCs were done at night, where the car was best able to cool down. I have both a covered and uncovered parking space; I use both about equally. I periodically do L1 charges -- which never raise temp. Most of the charges I do are QC (I live right next to a free QC, so I can't resist!)
3. Battery degradation seemed to correspond to ambient temperature more than how I treated it. Despite periods of heavy QC, the periodic heat waves affected SOH and AHr much more severely. The past few weeks the AHr has remained almost at a standstill (changing by about +/-0.1), which aligns conveniently to the more temperate weather we have been blessed with as of late!
I've had leaf spy pro from the start, but there are a few holes in the data (bluetooth hasn't always been enabled to pick up data). Nonetheless, there are enough data points to garner some value. If anyone would like the leafspy data, please let me know and I'll provide!
Picked up 2017 30 KWh Leaf on 07/2017. Live in SoCal (LA county). SOH was 100% when picked up. Stayed at 100% for about a month. Currently at 91% SOH, AHr 72.53, after 4 months of driving. Odometer reading at 3600. 80 QC, 99 L1/L2s. Many of those L1/L2s were done at the dealer (See below).
Needless to say, there is some pretty serious degradation already given the date of acquisition and mileage, but looks like this isn't an outlier. As has already been observed, age + mileage seem to be a secondary factor regarding degredation. This is a lease, so I'm not torn up over the fact.
Some interesting tidbits I've picked up thus far that may help the community:
1. The car was sitting on the lot for at least a few months before I leased it. When I picked up the car, it already had ~60 L1/L2 charges, with less than 200 miles on the odometer. I saw the dealer plug in the car after my 2 mile test drive (which started at full battery); I believe they always kept it at 100%. The car was not kept under shade at the dealer. Despite that, the car was at a very healthy 100% SOH and 80.6 AHr When I picked it up.
2. I follow the generally accepted guidelines for battery longevity -- as much as I can in the SoCal climate. Charging to ~80%, keeping battery above 20%, and (trying to) keep the battery as cool as possible. Most of my charging was to regain 25-50% of the battery. For the summer months, temp bars were almost always at 6; during the quick charges (which I kept <10 minutes), bars often hit 7 or 8. A couple of times I hit 9 temp bars, but immediately unplugged. Almost all QCs were done at night, where the car was best able to cool down. I have both a covered and uncovered parking space; I use both about equally. I periodically do L1 charges -- which never raise temp. Most of the charges I do are QC (I live right next to a free QC, so I can't resist!)
3. Battery degradation seemed to correspond to ambient temperature more than how I treated it. Despite periods of heavy QC, the periodic heat waves affected SOH and AHr much more severely. The past few weeks the AHr has remained almost at a standstill (changing by about +/-0.1), which aligns conveniently to the more temperate weather we have been blessed with as of late!
I've had leaf spy pro from the start, but there are a few holes in the data (bluetooth hasn't always been enabled to pick up data). Nonetheless, there are enough data points to garner some value. If anyone would like the leafspy data, please let me know and I'll provide!
SageBrush said:
The point is that the actual 100% SOC for the cell used in the Leaf could be at a value of several 100mv higher than the 100% SOC
indicated by the BMS and reported by LeafSpy. So when the BMS has ended charging at the expected 100% SOC, the actual SOC
for the Leaf's type of cell is less than 100% SOC by few 100mv. Which hasn't compromised the Leaf's range as would charging
to just 80% SOC, but reduces the likelihood of causing degradation by actually reaching true 100% SOC. This could easily be
done by using a smart voltage sensing ECU which senses the rate of change of cell voltages as it approaches 100% SOC, and
avoids those higher voltages on subsequent charges, thus avoiding the true 100% SOC.
Bottom line: Without fully characterizing (extensive analysis) the Leaf's cell, suggestions relating to charging are basically speculations.
