The 40KWH Battery Topic

[Astral]

I am not talking about 30-80%, never mentioned that? 30-70% on longer trips with qc charges is logical to me but I need to test it. If I go up to 80% as you say on the first QC then I will introduce additional heat into the battery which will never leave during the duration of the trip. I "think" it might be better to stop at 70% and not introduce the extra heat so on the next QC you would have a better starting point.

I am not sure if anybody tested this already, someone with more experience would be great to comment. I don't do many such trips, that is why I chose the Leaf as 95% of my driving is in town or between neighboring towns, So I don't have a big opportunity to do such tests.

 

[Oostenrijker]

30% - 70% means you only using 40% of the capacity, it will limit your range greatly. If you lucky you can do 100km with this, but I would drive down to 20% or even 10% before using QC again.

And then I would do until 80/90% the first quick charge, and the other sessions only until 65% SoC.

 

[Astral]

Look here: https://www.youtube.com/watch?v=zf-9nfX-mXs&t=730s
listen 45sec from 6min to 6:45

30-70 will not limit my range, it will make me stop more times but in the end could be faster and better
if chargers are available (and they are on the route i am planning) then why not?

In the end you will take overall less time to charge if rapidgate does not hit early on from first QC already.

 

[Oostenrijker]

I saw that video: it's very debatable, what's the best for the battery pack? But what about your time? If you only charge from 30% to 70% then you have to QC more frequently.

But if you leave with 100% SoC, drive 175km until you reach 10% SoC: charge until 80% or even 90% SoC? That's what I did during my trip to Austria.

Although my first QC was an free IKEA QC, limited to 20kW. By the time I was back from the restaurant, my car was almost already around 95% SoC. Reaching 10% isn't an goal for me, but when needed I would try to use as much capacity as possible.

Going to 10% from 100% actually means, using about 80% of the available battery capacity. Because about 10% is hidden, that's why with an Leaf it's totally fine to go down to --% and 100% is actually about 97% SoC.

My experience is: the more QC sessions you need, the longer your journey going take. So I would try to limit them, and instead of doing more QC sessions. I would just drive the battery more empty, and charge until 65% if Rapid gate is really bad.

You could also do like me: use some of those slow, free CHAdeMO chargers. And then go to the restaurant, after you back the car would be nicely charged.

( Going to all these QC chargers, means you need to detour slightly? Connect the cable everytime, start te charging etc. That takes time as well, and the Leaf battery ain't going cool much down from doing 30% to 70% SoC ).

It will cool down, over the night. Not between the Charging, and driving. Then it cools only slightly, and it hot climates it will overheat easily.

https://www.mynissanleaf.com/viewtopic.php?p=632921#p632921

This was my roadtrip: I roughly described, how it went.

 

[Astral]

I don't have any possibility of IKEA or any other such QC limited to 18-20kw. Only standard 50kw QC. No detour, motorway, very quick to stop. Also by not going too deep I have some reserve if I come across a charger that does not work or is occupied. For my trip to be enjoyable I need to have free chargers and also working ones. If I arrive with 30% battery, it is highly likely I will make it to the next one if needed, if I arrive with 10% and there is some problem then that would be really bad.

I don't know yet but I think anyway it is not possible to aim for 30-70 directly, always it will be 22% or 32%, depending where the charger is. But not going too deep on the battery I think is crucial to not allow heat to build up. Plus driving slow.

As Bjorn says, in the Leaf you have to drive slower to arrive faster...

 

[Oostenrijker]

As Bjorn says, in the Leaf you have to drive slower to arrive faster...

That's what I said as well: look at the range, my Leaf is currently showing.



You said you wanted to do 500km in two days? If the right conditions are met, I can do more than 230km and still having more than 30% SoC left. The Netherlands is flat like a dubbeltje, so ideal conditions if staying behind a truck who is doing 85km/h approximately.

And if it's about 20 degree, then it's still doable driving without airco. So if you drive slow, then with an Leaf: you actually win time. A fast charge, always makes you lose more time. Then the time you use more, by driving slower.

 

[Astral]

No, 574km in one trip. Elevation 100m to 1100m and everything in between, not flat

The car says aircon is only like -7km difference on a 200km stretch, Should not impact much, but yes, probably without aircon.

 

[LeftieBiker]

This is from a couple of weeks ago, when I ran LeafSpy on both cars. Sorry about not posting the screenshot, I'm a bit busy tonight.

AHr: 105.73

SOH: 91.59

370.91V

Hx: 105.28

ODO: 2560

1QC & 95 L1/L2s.

 

[hornstudio]

We had 4 weak cell pairs and Nissan replaced them.

SOC percentage is still jumping around below about 30%.

We drove 8 Miles at 50mph and guessometer dropped to 15%.

We parked the car and SOC jumped to 22%.

So capacity is always there but the gauge goes mad.

Hx is 46% only.

Any idea?

 

[Learjet]

We had 4 weak cell pairs and Nissan replaced them.

SOC percentage is still jumping around below about 30%.

We drove 8 Miles at 50mph and guessometer dropped to 15%.

We parked the car and SOC jumped to 22%.

So capacity is always there but the gauge goes mad.

Hx is 46% only.

Any idea?

Something is not right...had that problem before my weak cells were replaced...haven't seen that after the replacement.

 

[Stanton]

We had 4 weak cell pairs and Nissan replaced them.

SOC percentage is still jumping around below about 30%.

We need a LeafSpy voltage graph at that SoC.
If they didn't properly balance the cells (relative to the rest of the pack), then you will still have erratic behavior. I know, because I did this myself (replaced a weak cell/module); it's not easy to balance an individual cell/module, and even trained techs don't know the "tricks" involved.

 

[hornstudio]

At least 80mV difference at these 4 new cell pairs compared to the rest at about 30% SOC.

We have a 2nd car with 40kWh that balanced its replaced cells after 10000 miles.

Dealers should adjust voltage of new cells to other cells before they install - the just dont do it.

 

[Oostenrijker]

At least 80mV difference at these 4 new cell pairs compared to the rest at about 30% SOC.

We have a 2nd car with 40kWh that balanced its replaced cells after 10000 miles.

Dealers should adjust voltage of new cells to other cells before they install - the just dont do it.

Didn't know it can take that long? In that case, won't weak cells eventually be balanced out as well? I took a look at mine weak cells, and after a few times charging to 100% they definitely got less worse.

First I had 14 weak cell's according to Leafspy, but last time I looked: it only showed 4 weak cells, and also when I was doing an third party battery diagnostic test. It only showed 61mV difference at 14.5% Leafspy SoC.

If I hear your story: replacing those weak cells, doesn't necessarily solve things? I really hate these kind of cases. Often it feels like, once they repair something? They mess up other things?

My dealership couldn't even replace a windshield good the first time, and the second time it was way better. But still I had to wipe away some finger marks, on the inside of the new windshield. But I decided to cut them some slack.... but I can't imagine, they know how to replace battery cells properly...

 

[hornstudio]

I could post so many interesting screen shots of at least 50 Nissans I had between my fingers but its not convenient to do. That IS a problem.

 

[Stanton]

Dealers should adjust voltage of new cells to other cells before they install - the just don't do it.

This is exactly the problem: it takes time (and a bit of planning) to balance cells outside the pack (with a cell-based LiOn charger) with cells inside the pack (via the J1772 port). Most techs just don't care to take the time.
A tip for those who plan on doing it (I replaced a weak cell/module in my pack): it's best to insert the new module at a voltage level slightly above the rest of the pack. That way the same cell/module doesn't continue to limit/reduce your low-end SoC, and your overall capacity will tend to rise (albeit very slightly) as that "new" module ages/degrades. It has taken mine almost a year to knock ~20mV off of the voltage delta (I still don't quite get to ~400V for a full pack).

 

[LeafyMaple]

Hi, group. I'm first time poster. Got our 2019 Leaf several weeks ago with 11,500 miles on it. I'm seeing erratic SOC indications below 74%.
It is a Nissan certified pre-owned vehicle and I have an appointment with the dealership. Hoping they can resolve the issue.

Thanks for all of the fantastic information sharing here!

 

[ebeighe]

I am (in theory) waiting for a replacement pack for a degraded 30kwh pack in a 2017.

My service advisor claims she's seen "at least two" re-manufactured (or possible said re-cycled, or re-furbished?) replacement packs.

Has there been any confirmed reports of such (from Nissan, not after-marked)?

 

[LeftieBiker]

I can't think of any. Keep in mind that Nissan dealership people have been known to say some crazy, and sometimes demonstrably untrue, things to Leaf drivers. I was recently told by a Nissan EV helpline person that Nissan had ended all telematics services for all '21 and newer Leafs, effective last June...

 

[LeafyMaple]

Newbie, here wondering if someone seasoned would be willing to interpret these cell voltage readings from my local Nissan dealer:

CELL VOLTAGE 78, 3921 mV
CELL VOLTAGE 79, 3910 mV
CELL VOLTAGE 80, 3920 mV
CELL VOLTAGE 81, 3908 mV
CELL VOLTAGE 82, 3919 mV
CELL VOLTAGE 83, 3911 mV
CELL VOLTAGE 84, 3920 mV
CELL VOLTAGE 85, 3916 mV
CELL VOLTAGE 86, 3739 mV
CELL VOLTAGE 87, 3910 mV
CELL VOLTAGE 88, 3918 mV

It was briefly explained to me that the 3739 reading indicates a problem in at least one cell?
I have a follow up appointment for them to further investigate and perform the repair. I'm told wait times on this can be unpredictable.
I welcome your insights.

 

[Stanton]

Newbie, here wondering if someone seasoned would be willing to interpret these cell voltage readings from my local Nissan dealer:

CELL VOLTAGE 78, 3921 mV
CELL VOLTAGE 79, 3910 mV
CELL VOLTAGE 80, 3920 mV
CELL VOLTAGE 81, 3908 mV
CELL VOLTAGE 82, 3919 mV
CELL VOLTAGE 83, 3911 mV
CELL VOLTAGE 84, 3920 mV
CELL VOLTAGE 85, 3916 mV
CELL VOLTAGE 86, 3739 mV
CELL VOLTAGE 87, 3910 mV
CELL VOLTAGE 88, 3918 mV

It was briefly explained to me that the 3739 reading indicates a problem in at least one cell?
I have a follow up appointment for them to further investigate and perform the repair. I'm told wait times on this can be unpredictable.
I welcome your insights.

Probably better to have started a separate topic (I'll let the moderator decide), but it looks like you definitely have a weak cell. Would be better to have some context (SoC?) and even a LeafSpy graph, but a 200 mV difference in small sample is not good.
FWIW, "unpredictable" wait times is an understatement. First you have to get Nissan to agree/admit it's bad enough to trigger a warranty replacement...and then you have to wait for them to send the dealer a good module. It's a full day job (if you had to pay for it yourself).