Long Term Reliability of the 30kWh Battery Pack

coupedncal said:

How do we propose we do this? Use LeafSpy type tool?

I am confused by this apparent fix from Nissan as even the LeafSpy tool was reporting lower values and thereby implying the battery storage capacity was dropping rapidly on these 30 kWh models. Am I correct with this statement? This fix will resolve the dashboard inaccuracies but wasn't LeafSpy tapping the batteries directly and LeafSpy did not use the input from the dash?

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Small point of clarification; The dashboard displays were likely accurate. Well as accurate as you can be when using invalid data I guess. The error is basically at the very foundation of the battery pack itself so EVERYTHING is potentially affected.


LEAF Spy only parrots what it sees on the bus. So any miscalculation would be passed on. The real concern is what other changes will happen with the correct calculations?

Realize it is possible that the BMS allowed the pack to charge to full speed up to 80% SOC (something ONLY the 30 kwh pack does thru out the entire industry) because of bad info it was receiving from the LBC.

So fix the info and now the BMS starts ramping down the charge at 63% SOC like the 40 kwh pack did (24 kwh pack ramped down earlier)


A possibly good analogy (any analogy requires being on the same plane of thought)

You are in Detroit, Michigan and want to navigate to 123 Baker St, Detroit, Michigan.

So you get directions from the NAV but the NAV doesn't realize its in Detroit, Kansas navigating to 123 Baker St, Detroit, Kansas. It only knows you must travel in a specific direction for a specific distance and then turn right...

edatoakrun said:

DaveinOlyWA said:

edatoakrun said:

So, nissan says that after the update, the capacity bar display will now be "accurate".

Forgive me, but has Nissan ever stated what "accurate" capacity each bar represents?

All Nissan was ever willing to say about the "24 kWh" pack capacity, was that four bars lost represented approximately 30% of new capacity.

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The bars will not change. They are simply a representation of the state of the car. They are NOT to be considered as digital representations of anything ...

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Yes, and the same can be said for the grossly inaccurate LBC estimates of battery capacity, which are used to inform the bar displays.

Unfortunately, most "30 kWh" pack LEAF owners seem to have been just as willing to make fools of themselves, as most "24 kWh" pack owners have over the years, when they took LBC data seriously as accurate data on pack capacity.

So, with is campaign, Nissan will now change the LBC readings on "30 kWh" packs, allegedly to make them less inaccurate, just like it claimed it was trying to do for our "24 kWh" LEAFs.

That effort was a failure, as the higher-capacity LBC readings soon drifted back to ~the same level of extreme inaccuracy, as confirmed by recharge and range tests on my LEAF and others' at the time.

But, maybe this time it will be different?

If any of you "30 kWh" pack owners want to find out, I suggest you try to learn what you have neglected to learn to date, how to monitor your pack capacity accurately, using objective methods, and entirely ignoring the garbage data from your LBC, and that you do so before you accept Nissans "corrective" campaign.

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Your strategy is flawed. No matter how you measure the battery capacity, you are limited to Nissan's information as to the state of the battery. Even you run the battery to "turtle" and carefully measure the power used to recharge, you are limited to Nissan's evaluation of both turtle and 100% charged. It doesn't matter if the BMS is giving false information because short of pulling the battery out of the car and bench testing it you are limited to what the BMS says the state of the battery is. If you accept that battery voltage is directly comparable to state of charge then unless the BMS is falsely interpreting the battery voltage these batteries are losing capacity. While I haven't specifically checked for a change in the voltage level at low charge levels (I.E. LBW, VLBW) I also haven't noticed any real variation either. Since I now have a new battery I can't check the voltages at LBW or VLBW on a degraded battery. Perhaps someone else could do it and report their findings.

30kWh at turtle with 8 bars

min/avg/max 3.426/3.456/3.494

before reset AHr=50.51 SOH= 63.55 Hx=60.59%

Temp F = 106.9 106.7 105.3