The 62kWh Battery Topic

[SageBrush]

Multiple full accelerations this am...but not really cold...no DTC.

What SoC ?
I think I would shoot for 30% - 50% SoC

 

[knightmb]

Multiple full accelerations this am...but not really cold...no DTC.

What SoC ?
I think I would shoot for 30% - 50% SoC

Might have to get more drastic to get a long enough "drain" of power to get that weak Cell to really pass out, like along the lines of running the climate control on 90F, deflate tires down to 30 psi to create as much drag as possible without damaging the tires, have all the windows down to kill the aero effect, maybe tow another Leaf behind it too. :lol:

 

[GerryAZ]

It is time to post results of the latest discharge test for my 2019 SL Plus. Although it lost almost 1 Ahr during the last 90-day adjustment (in January), it still has 92.8% of original battery storage capacity (based upon charging energy from the wall) after 43,401 miles and 2-1/2 years of use. Ahr is still 90.7% of reading after first full charge. Gids are still 93.0% of reading after first full charge. Discharge tests are performed every 3 months by driving the car until battery is deeply discharged and then running HVAC in the driveway until shutdown (main DC contactor opens). The car is then charged fully using AeroVironment 240-volt, 30-ampere L2 EVSE. Charging energy is measured by a revenue accuracy digital meter on the 240-volt input to the EVSE.

 

[GerryAZ]

Here is a cell voltage screenshot just before shutdown on 2/13/2022:

 

[GerryAZ]

Here is a screenshot after charging on 2/13/2022:

 

[GerryAZ]

Here is a cell voltage screenshot at about 30% SOC on 2/16/2022:

 

[LeftieBiker]

That color scheme makes it REALLY hard to see how low #65 is. Amazing how much it recovered. I guess then that at least 300mv at a low SOC is needed to trigger a DTC...

 

[SageBrush]

I guess then that at least 300mv at a low SOC is needed to trigger a DTC...

I would not come to that conclusion, since multiple other cells were also low voltage

 

[GerryAZ]

The lowest cell voltage just before shutdown was 2.451 volts. The pack is well-balanced because I usually discharge deeply and charge fully each charge cycle. The voltages are normally well-balanced until the battery is very deeply discharged (almost down to Turtle). You can see this by looking at the screenshot for about 30% SOC with only 16 mV difference between minimum and maximum. The 9 mV difference at full charge is typical for this car.

 

[goldbrick]

The voltages are normally well-balanced until the battery is very deeply discharged

Is that because the V/Ahr curve is so steep at that voltage? That would make the most sense to me since a small Ahr difference would make a large V difference at that point.

 

[knightmb]

I guess then that at least 300mv at a low SOC is needed to trigger a DTC...

I would not come to that conclusion, since multiple other cells were also low voltage

Unfortunately, all we can do is guess.
My guess would be once the Leaf hits the 0% mark where it blanks out the battery percent, it's not going to DTC on anything since the voltage spread is so random at such a low discharge level, otherwise we all would have probably generated some DTC by now, me especially since I liked to push my Leaf range to the max for testing reasons.

Do we have enough data either here on this forum or other places (like Facebook :roll: ) to extrapolate a range at least of what seems to trigger it? I don't remember reading anything, anywhere about anyone getting a 62 kWh battery replaced under warranty yet. Having a pack with a one-off weak cell can certainly be annoying for the technical owners here.

 

[SageBrush]

Having a pack with a one-off weak cell can certainly be annoying for the technical owners here.

It is a lot more than annoying. At minimum it is a severe manufacturing defect that reduces range; at worst it is a severe safety issue.

 

[DaveinOlyWA]

I guess then that at least 300mv at a low SOC is needed to trigger a DTC...

I would not come to that conclusion, since multiple other cells were also low voltage

Unfortunately, all we can do is guess.
My guess would be once the Leaf hits the 0% mark where it blanks out the battery percent, it's not going to DTC on anything since the voltage spread is so random at such a low discharge level, otherwise we all would have probably generated some DTC by now, me especially since I liked to push my Leaf range to the max for testing reasons.

Do we have enough data either here on this forum or other places (like Facebook :roll: ) to extrapolate a range at least of what seems to trigger it? I don't remember reading anything, anywhere about anyone getting a 62 kWh battery replaced under warranty yet. Having a pack with a one-off weak cell can certainly be annoying for the technical owners here.

There have been a few like maybe 2-3 that had cell failure early. No DTCs iirc, just dash weirdness. One posted a video on FB showing SOC going from 80% SOC to 30% SOC or something along those lines, turtling and then on restart going back to 70ish % all within 15 minutes.

I think LS showed voltage delta around 200 mv but restricted to a handful of cells while the rest of the pack was maybe 25ish?

 

[knightmb]

There have been a few like maybe 2-3 that had cell failure early. No DTCs iirc, just dash weirdness. One posted a video on FB showing SOC going from 80% SOC to 30% SOC or something along those lines, turtling and then on restart going back to 70ish % all within 15 minutes.

I think LS showed voltage delta around 200 mv but restricted to a handful of cells while the rest of the pack was maybe 25ish?

Thanks for looking all that up. I guess I need to buddy up with a certified Leaf tech in my area, should answer a lot of questions.

 

[DaveinOlyWA]

There have been a few like maybe 2-3 that had cell failure early. No DTCs iirc, just dash weirdness. One posted a video on FB showing SOC going from 80% SOC to 30% SOC or something along those lines, turtling and then on restart going back to 70ish % all within 15 minutes.

I think LS showed voltage delta around 200 mv but restricted to a handful of cells while the rest of the pack was maybe 25ish?

Thanks for looking all that up. I guess I need to buddy up with a certified Leaf tech in my area, should answer a lot of questions.

Well had I actually looked it up, I could have provided a link. Its actually something I saw on my frequent Facebook scans. Issue started last Summer, took a few trips to the dealership before they even acknowledged it was an issue which means "No DTC, no problem"

It was only after escalating the issue along with providing the damning video did anyone take notice. He has been enjoying his new pack for a few months now. Although there is only one bad module, they swapped out the entire pack.

 

[DaveinOlyWA]

There have been a few like maybe 2-3 that had cell failure early. No DTCs iirc, just dash weirdness. One posted a video on FB showing SOC going from 80% SOC to 30% SOC or something along those lines, turtling and then on restart going back to 70ish % all within 15 minutes.

I think LS showed voltage delta around 200 mv but restricted to a handful of cells while the rest of the pack was maybe 25ish?

Thanks for looking all that up. I guess I need to buddy up with a certified Leaf tech in my area, should answer a lot of questions.

Well had I actually looked it up, I could have provided a link. Its actually something I saw on my frequent Facebook scans. Issue started last Summer, took a few trips to the dealership before they even acknowledged it was an issue which basically means "No DTC, no problem"

It was only after escalating the issue along with providing the damning video did anyone take notice. He has been enjoying his new pack for a few months now. Although there is only one bad module, they swapped out the entire pack.

 

[Learjet]

update...annual battery health check completed today and no issues noted....even my 3 year old 12 volt tested good :roll:

So I will live with the weak cell, GOM weirdness around 30% mark and reduced range until something changes

 

[user 24513]

update...annual battery health check completed today and no issues noted....even my 3 year old 12 volt tested good

Did you go to the dealer for this check? and was there a cost? Thanks!

 

[Learjet]

update...annual battery health check completed today and no issues noted....even my 3 year old 12 volt tested good

Did you go to the dealer for this check? and was there a cost? Thanks!

Yes dealer with a certified Leaf tech....the only one in Baton Rouge, LA....no cost under warranty for the first three years.

 

[knightmb]

My 2020 Leaf hits the 2 year birthday. I've only owned it for a year now, but put close to +30k miles in one year on it. Still getting 100% of the it's rated range, despite what the battery SOH says. :?