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Re: The 62kWh Battery Topic

Posted: Sat Nov 21, 2020 4:28 pm
by LeftieBiker
I think that if the imbalance is modest, then top balancing by charging to 100% is beneficial. If you have big differences in cell voltages then it may not matter, as the leaf BMS can't handle large balancing loads. We got well-balanced packs in both our new leafs, so the plan is to charge to 100% occasionally, before use.

Re: The 62kWh Battery Topic

Posted: Sat Nov 21, 2020 10:11 pm
by DaveinOlyWA
DougWantsALeaf wrote:
Sat Nov 21, 2020 4:05 pm
Question for the board.


Do you think there is is value is occationally charging the car to 100%? I see often in the Tesla forums that it helps to align the bms to know the top of the pack. Do we think the same holds for the Leaf?

S+ owners, do you think the S+ has any better air cooling than the SV/SL+ as there is less equipment in the front of the car? (Different than the lessor heating as the car takes less power to propel the car)
1) No. Pack balance happens all the time and I have never seen anyone able to bring any cell back in line with any method of charging. Another point is there have been random failed cells and most charged to full on a regular basis so it didn't help them. I do believe that balancing only alleviates small differences in the quality of the cell. Big differences will simply fail eventually.

2) The front of the LEAF has liquid cooling with a radiator and the whole 9 yards but it only cools the motor inverter. The battery being in the back wouldn't get any benefit of air flow.

Re: The 62kWh Battery Topic

Posted: Sun Nov 22, 2020 3:05 pm
by SageBrush
DaveinOlyWA wrote:
Sat Nov 21, 2020 10:11 pm

1) No. Pack balance happens all the time and I have never seen anyone able to bring any cell back in line with any method of charging. Another point is there have been random failed cells and most charged to full on a regular basis so it didn't help them. I do believe that balancing only alleviates small differences in the quality of the cell. Big differences will simply fail eventually.
The Tesla behavior is meant to correct or prevent calibration drift and artefactual drop in battery capacity. It has nothing to do with rejuvenating cells.

No one knows how Nissan calibrates the SoC meter for the LEAF, so it is unknown if the Tesla method is helpful. It would not hurt.

Re: The 62kWh Battery Topic

Posted: Sun Nov 22, 2020 3:36 pm
by DougWantsALeaf
That is what I am thinking, do 1 100% charge a quarter for good measure.

I am very curious to see what my (2019) S+ does next month at its next quarterly. Its still sitting at 97.97% SoH which i imagine can't last.

Re: The 62kWh Battery Topic

Posted: Sun Nov 22, 2020 7:56 pm
by DaveinOlyWA
DougWantsALeaf wrote:
Sun Nov 22, 2020 3:36 pm
That is what I am thinking, do 1 100% charge a quarter for good measure.

I am very curious to see what my (2019) S+ does next month at its next quarterly. Its still sitting at 97.97% SoH which i imagine can't last.
What happens when you do 2-3 full charges in a week? Does the capacity rise on each charge implying top end balance? As far as Tesla requiring a full charge to recalibrate its system?? Interesting... A better question is would I care about a few miles of range loss from not doing full charges regularly and my answer is "I am sorry but I didn't notice anything missing" :lol:

Re: The 62kWh Battery Topic

Posted: Sun Nov 22, 2020 10:28 pm
by GerryAZ
DaveinOlyWA wrote:
Sun Nov 22, 2020 7:56 pm
DougWantsALeaf wrote:
Sun Nov 22, 2020 3:36 pm
That is what I am thinking, do 1 100% charge a quarter for good measure.

I am very curious to see what my (2019) S+ does next month at its next quarterly. Its still sitting at 97.97% SoH which i imagine can't last.
What happens when you do 2-3 full charges in a week? Does the capacity rise on each charge implying top end balance? As far as Tesla requiring a full charge to recalibrate its system?? Interesting... A better question is would I care about a few miles of range loss from not doing full charges regularly and my answer is "I am sorry but I didn't notice anything missing" :lol:
I suspect deep discharge and full charge once in a while does allow the BMS system to get a better estimate of actual battery capacity. Whether that is good or bad can be argued. You may not have noticed my post on 11/12 a couple pages back in this thread that shows my battery statistics after my latest full discharge/charge test. As of now, my car has 22,863 miles and Leaf Spy statistics are: AHr=166.03, SOH=94.12%, and Hx=101.33%. As you know, I typically charge fully and deeply discharge each charge cycle.

Re: The 62kWh Battery Topic

Posted: Mon Nov 23, 2020 7:37 am
by DaveinOlyWA
GerryAZ wrote:
Sun Nov 22, 2020 10:28 pm
DaveinOlyWA wrote:
Sun Nov 22, 2020 7:56 pm
DougWantsALeaf wrote:
Sun Nov 22, 2020 3:36 pm
That is what I am thinking, do 1 100% charge a quarter for good measure.

I am very curious to see what my (2019) S+ does next month at its next quarterly. Its still sitting at 97.97% SoH which i imagine can't last.
What happens when you do 2-3 full charges in a week? Does the capacity rise on each charge implying top end balance? As far as Tesla requiring a full charge to recalibrate its system?? Interesting... A better question is would I care about a few miles of range loss from not doing full charges regularly and my answer is "I am sorry but I didn't notice anything missing" :lol:
I suspect deep discharge and full charge once in a while does allow the BMS system to get a better estimate of actual battery capacity. Whether that is good or bad can be argued. You may not have noticed my post on 11/12 a couple pages back in this thread that shows my battery statistics after my latest full discharge/charge test. As of now, my car has 22,863 miles and Leaf Spy statistics are: AHr=166.03, SOH=94.12%, and Hx=101.33%. As you know, I typically charge fully and deeply discharge each charge cycle.
Which implies that our large early degradation is a false reading? Because there is no evidence that deep cycling is beneficial, is there? If there is, I haven't seen it. Either way, I will be doing some longer distance trips when this CV thing blows over. I should see a dramatic change if this is the case. I expect to see I might see a bit of a change but probably no more than 1% like my 2018. I am a rarity in the "never charge past 75%" arena. Most people charge like you do.

Re: The 62kWh Battery Topic

Posted: Mon Nov 23, 2020 11:55 am
by DougWantsALeaf
Gerry

Your stats are particularly positive given that Arizona went through 3 solid weeks of over 110F weather this year.

Re: The 62kWh Battery Topic

Posted: Mon Nov 30, 2020 7:13 pm
by DougWantsALeaf
Anyone see this and know where we can find a 300 amp Chademo? It looks like 100kW is very possible.

https://electricrevs.com/2019/01/14/nis ... but-where/

Re: The 62kWh Battery Topic

Posted: Tue Dec 01, 2020 6:44 am
by DaveinOlyWA
DougWantsALeaf wrote:
Mon Nov 30, 2020 7:13 pm
Anyone see this and know where we can find a 300 amp Chademo? It looks like 100kW is very possible.

https://electricrevs.com/2019/01/14/nis ... but-where/
Someone mentioned a new install advertised at 100 KW in PA I believe. Not sure of the particulars since its location means I won't likely be using it any time soon.