GaleHawkins
Well-known member
SageBrush said:
By an accident that is often the case after spending 100's of hours studying Leaf battery degradation issues and related factors.
2016-2017 model year 30 kWh bar losers and capacity losses
- Thread starter cwerdna
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By an accident that is often the case after spending 100's of hours studying Leaf battery degradation issues and related factors.
GaleHawkins
Well-known member
SageBrush said:
By an accident that is often the case after spending 100's of hours studying Leaf battery degradation issues and related factors.
GaleHawkins
Well-known member
I have been using Leaf spy Pro for 3 years now.
I am new to MNL site and trying to find my way around. I have a 2017 Leaf with 31,180 mi., 3 years left on my warranty and I lost my second bar at around 29,000. A friend used his LeafSpy to tell me my SOC is 77.2. Most of the technical language is over my head. Could someone suggest some very simple steps I could follow to gain more informaton about the condition of my battery? Thanks
Welcome. I assume that your friend either said or meant "SOH" rather than "SOC," which just means "state of charge." The State of Health correlates pretty much exactly with the remaining battery capacity, so if that number is SOH, then you have 77% of the original capacity remaining. I'm going to link my used Leaf buying guide shortly; pay particular attention to the section on the 30kwh Leafs.
http://www.mynissanleaf.com/viewtopic.php?p=538030
http://www.mynissanleaf.com/viewtopic.php?p=538030
GaleHawkins
Well-known member
SageBrush said:
That's good since I am not trying to convince anyone of anything.
My discovery due to getting our Leaf totalled and a bug getting me down for a long haul that per Spy Leaf Pro data indicates SOH stops while the 12v negative battery is removed in our 2016 Leaf with the 40 kWh battery pack.
My post is geared to the scientific minded Leaf owners that may have LSP and a parked Leaf to see if they can duplicate my accidental and surprising results.
I'm trying to milk 10 years out of this new battery installed by Nissan Feb 2020 hoping by 2030 Tesla will have their $20K EV on the market.
The 2015 Prius C is impressing me more everyday and it will enable in future heat waves to park the Leaf with the negative 12v cutoff switch open.
LeftieBiker said:
I have to correct my information. The '77.2 SOC' is irrelevant. What I want to know is at what point of my SOH rating should I expect to lose my 9th and 8th bar. Sorry for the misinformation. Your info and patience is greatly apprectaied.
No problem. I don't have that info available right now, but I'm sure that someone will post it tonight. As noted in the buying guide, you have to have a software update to be eligible for a free battery, and that will likely bring the missing bars back, at least for a while.
I'm relieved. For a moment there, it sounded like you were saying that disconnecting the 12v retards battery degradation because the SoH stays the same. I should have known that a smart, scientifically minded guy like you would not push such a weak notion without better evidence.GaleHawkins said:
Yes. The update is free. Nissan claims that there is nothing wrong with the 30kwh batteries other than a glitch in the Battery Management System (BMS) that causes it to under-report the capacity, and that the update fixes the issue. Since they have run out of 30kwh batteries and are now installing 40kwh batteries as warranty replacements, I think that that is not quite the whole story. My opinion is that there is a serious issue with many - but not all - of the 30kwh packs, and that they range in quality and longevity from "great" to "lousy."
goldbrick
Well-known member
RandalC said:
The dealer should have and probably did do the BMS firmware update at that time but it's possible is hasn't been done. You can check whether or not the update has been done with LeafSpy. https://www.youtube.com/watch?v=H-Eq93RniJ8
From memory, I think I've heard of several 30kWh batteries losing the 4th bar at around 65% SOH but it seems to vary a bit.
GaleHawkins
Well-known member
SageBrush said:
I not say it "retards" battery SOH decline per LSP. I posted it freezes battery SOH decline per LSP as long as the 12v battery is electrically removed.
Of course a Leaf in daily use can't do this test. Our Leaf SOC was at 88% when totalled in Nov 2019. From test drives, trip to court house and driven to the body shop, etc SOC was down to about 50% when we first charged 18 months later and of course the SOH only declined days the 12v battery was connected. In 18 months total SOH decline dropped from 96.08 to 95.72. when the 12 volt battery is connected it continues to decline at 0.01% daily on average.
Do you still have a Leaf to see if you can freeze your SOH loss by removing your 12v negative battery cable?
GaleHawkins
Well-known member
SageBrush said:
You followed my testing procedure and was able freeze your SOH I Iake it.
Oils4AsphaultOnly
Well-known member
GaleHawkins said:SageBrush said:
You followed my testing procedure and was able freeze your SOH I Iake it.
I think Sagebrush's point was that the SOH value came only from the BMS, and that the margin of error on that value is high enough that you really can't conclude that you've halted SOH degradation by simply disconnecting the 12v battery for a fully disconnected "shelf-storage".
As a data point, while waiting for the 4th bar to drop (mine did it at 65.84% SOH, while others dropped a little earlier than this), I noticed that the SOH value went UP a day later (probably due to weather change?) by about 0.08%. With that kind of error rate, you're going to need to have a ton more data before you can be sure that the degradation had actually dropped.
As a shade-tree electrician (computer engineer by training), I can see the logic that disconnecting the main pack from the 12v battery would remove a parasitic load from the main pack (and thus reduce the charge cycling). But that thinking is incomplete. Even though you've removed the electrical load, the thermal load on the liquid electrolyte is still present, which is why calendar degradation is a thing. You're in KY, so your weather is better for maintaining battery health, but it would NOT work in warmer climates like the southwestern states.
As for the Prius C, it's a non-plug-in hybrid, why forgo putting miles on the Leaf just to preserve its battery for 10 years?
Edit: @ RandalC, mine dropped the 4th bar at 65.84%, I've seen others dropped within 1% of that value. So 66.8% - 64.8%.
GaleHawkins
Well-known member
Oils4AsphaultOnly said:GaleHawkins said:SageBrush said:
You followed my testing procedure and was able freeze your SOH I Iake it.
I think Sagebrush's point was that the SOH value came only from the BMS, and that the margin of error on that value is high enough that you really can't conclude that you've halted SOH degradation by simply disconnecting the 12v battery for a fully disconnected "shelf-storage".
As a data point, while waiting for the 4th bar to drop (mine did it at 65.84% SOH, while others dropped a little earlier than this), I noticed that the SOH value went UP a day later (probably due to weather change?) by about 0.08%. With that kind of error rate, you're going to need to have a ton more data before you can be sure that the degradation had actually dropped.
As a shade-tree electrician (computer engineer by training), I can see the logic that disconnecting the main pack from the 12v battery would remove a parasitic load from the main pack (and thus reduce the charge cycling). But that thinking is incomplete. Even though you've removed the electrical load, the thermal load on the liquid electrolyte is still present, which is why calendar degradation is a thing. You're in KY, so your weather is better for maintaining battery health, but it would NOT work in warmer climates like the southwestern states.
As for the Prius C, it's a non-plug-in hybrid, why forgo putting miles on the Leaf just to preserve its battery for 10 years?
Edit: @ RandalC, mine dropped the 4th bar at 65.84%, I've seen others dropped within 1% of that value. So 66.8% - 64.8%.
I'm not claiming I can stop SOH losses by removing the negative 12v cable.
That is what Leaf Spy Pro is claiming.
At one point there was some LSP users on this site and was hoping there still was someone with a Leaf that sat weeks sometimes that would test an see if LSP would give them the same or different results.
I purchased the Leaf as a EV test bed to help me learn for myself and family about the EVS coming down the pike.
My son thinks a RAV 4 plug in might be a better option than a Model Y hence the Prius C test bed. I am beyond impressed Prius C (Yaris). At 103K miles the drive drive line is awesome I can coach a mile out of it in EV Mode only. 50 miles per gallon is awesome but I still have to stop for gas.
Oils4AsphaultOnly
Well-known member
GaleHawkins said:Oils4AsphaultOnly said:GaleHawkins said:You followed my testing procedure and was able freeze your SOH I Iake it.
I think Sagebrush's point was that the SOH value came only from the BMS, and that the margin of error on that value is high enough that you really can't conclude that you've halted SOH degradation by simply disconnecting the 12v battery for a fully disconnected "shelf-storage".
As a data point, while waiting for the 4th bar to drop (mine did it at 65.84% SOH, while others dropped a little earlier than this), I noticed that the SOH value went UP a day later (probably due to weather change?) by about 0.08%. With that kind of error rate, you're going to need to have a ton more data before you can be sure that the degradation had actually dropped.
As a shade-tree electrician (computer engineer by training), I can see the logic that disconnecting the main pack from the 12v battery would remove a parasitic load from the main pack (and thus reduce the charge cycling). But that thinking is incomplete. Even though you've removed the electrical load, the thermal load on the liquid electrolyte is still present, which is why calendar degradation is a thing. You're in KY, so your weather is better for maintaining battery health, but it would NOT work in warmer climates like the southwestern states.
As for the Prius C, it's a non-plug-in hybrid, why forgo putting miles on the Leaf just to preserve its battery for 10 years?
Edit: @ RandalC, mine dropped the 4th bar at 65.84%, I've seen others dropped within 1% of that value. So 66.8% - 64.8%.
I'm not claiming I can stop SOH losses by removing the negative 12v cable.
That is what Leaf Spy Pro is claiming.
At one point there was some LSP users on this site and was hoping there still was someone with a Leaf that sat weeks sometimes that would test an see if LSP would give them the same or different results.
I purchased the Leaf as a EV test bed to help me learn for myself and family about the EVS coming down the pike.
My son thinks a RAV 4 plug in might be a better option than a Model Y hence the Prius C test bed. I am beyond impressed Prius C (Yaris). At 103K miles the drive drive line is awesome I can coach a mile out of it in EV Mode only. 50 miles per gallon is awesome but I still have to stop for gas.
All my SOH readings are from Leaf Spy Pro. That's why I can tell you that the reading has a margin of error, and the source of that error is the BMS.
I've driven a Prius before, and it just takes too much work for too little gain. The Leaf is a much better commuter vehicle