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Re: Cell Voltage Loss Inspection test (cell-pair test), P33E6

Posted: Sat Jul 20, 2019 1:10 pm
by SageBrush
Marktm wrote:If I recall, this was when "turtle" was activated. I may have even used the heater until the drive system shutdown. The error code P33E6 was not set.
Your story is probably similar JerrtyAZ then: meets cvli criteria but absent the DTC Nissan is not interested.

In your shoes I would complain of a loss of power and let them figure out why.

Re: Cell Voltage Loss Inspection test (cell-pair test), P33E6

Posted: Sat Jul 20, 2019 5:24 pm
by Marktm
I have thought of taking it to the same dealer that did the replacement and at least get the facts on record. The problem is that LeafSpy has the "facts" and without a DTC, I don't think they will do anything. I've been working with this dealer on some vehicle to grid initiatives and fleet purchases, so they might take it to their EV "experts"? Probably worth a try.

BTW, the "normal" mv range is 20-30 mv when above VLBW, and the range seems about as expected, so I do wonder if the two cells might need better balancing than the management system can normally provide. Above my pay grade, however.

Re: Cell Voltage Loss Inspection test (cell-pair test), P33E6

Posted: Sat Jul 20, 2019 5:41 pm
by SageBrush
The only fact I would relay is that the car goes into turtle mode when it still has charge in the battery.

Re: Cell Voltage Loss Inspection test (cell-pair test), P33E6

Posted: Sat Jul 20, 2019 6:03 pm
by LeftieBiker
Ask them to have a Leaf tech drive it up a steep hill with 10% SOC.

Re: Cell Voltage Loss Inspection test (cell-pair test), P33E6

Posted: Sat Jul 20, 2019 7:27 pm
by SageBrush
LeftieBiker wrote:Ask them to have a Leaf tech drive it up a steep hill with 10% SOC.
Exactly, with the pedal to the floor

Re: Cell Voltage Loss Inspection test (cell-pair test), P33E6

Posted: Sun Jul 21, 2019 6:16 am
by Marktm
Guys, I live in Houston, TX - the only steep hills are freeway overpasses where everyone is going between 75 and 95 mph! OK, I might be exaggerating :mrgreen:

It's very interesting-what you are recommending! So you expect that this might actually help throw the code and/or simply be obvious from the "feel" and/or the power level recorded on LeafSpy or even the GOM - that the power level is restricted by the "bad" cells? I think I see where you are going.

Re: Cell Voltage Loss Inspection test (cell-pair test), P33E6

Posted: Sun Jul 21, 2019 8:22 am
by Lothsahn
Honestly, while the cells are lower, I don't know that I'd call them bad. 5.5% SOC is very very low, so they're probably just the weakest two.

Its very different than when you're at 25 or 50% SOC and you see that difference. If that happens, you have bad cells. Given the li-ion discharge curve, those cells are within 5% capacity difference of the others. Replacing the cells would likely provide you very little difference on range.

I used to get 250-300mv differences in my car all the time at VLBW, but that's because it had 7 bars.

Re: Cell Voltage Loss Inspection test (cell-pair test), P33E6

Posted: Sun Jul 21, 2019 8:43 am
by SageBrush
Lothsahn wrote:5.5% SOC is very very low, so they're probably just the weakest two.
Note that the 5.5% SoC in this pack is a voltage of 334 volts. That is way above turtle.

The manual will have to be checked, but I *think* that the LEAF should have full power from VLBW and above.

As for how to document power loss: it may be as simple as less power rings light up on the display under full acceleration; or it may take a simple comparison of say ... 0-60 mph time.

Re: Cell Voltage Loss Inspection test (cell-pair test), P33E6

Posted: Sun Jul 21, 2019 8:47 am
by SageBrush
Marktm wrote: So you expect that this might actually help throw the code and/or simply be obvious from the "feel" and/or the power level recorded on LeafSpy or even the GOM - that the power level is restricted by the "bad" cells? I think I see where you are going.
Right, and you do not need a hill.

Just document that maximum power is hobbled when it should not be. Hills are recommended because they give you an opportunity to floor the go pedal for a longer time. I imagine that flooring both pedals at the same time is the same test.

Re: Cell Voltage Loss Inspection test (cell-pair test), P33E6

Posted: Sun Jul 21, 2019 10:49 am
by Marktm
Will set up a "test", take data and get back. Fun project for a retired guy! Just hope I don't have to push my leaf for a block to get to the front of my house after I went too far with battery depletion :shock: I was definitely a newbie at that time!

Interesting concept of pushing both "pedals" - it would seem regen and accel at the same time would cancel, or is the CAN system smart enough to only use the disks brakes when accelerating?