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2011-2012 HV battery reset

Posted: Wed Sep 28, 2016 12:37 pm
by electromotive
Has anyone else noticed the growing number of used LEAFs offered for sale with 10, 11, and 12 capacity bars? This is fraudulent activity and California authorities may want to investigate.
Thank you to anyone that responds with his/her thoughts on this matter.

Re: 2011-2012 HV battery reset

Posted: Wed Sep 28, 2016 3:37 pm
by baustin
It is only fraudulent activity if the BMS is purposely reset to hide the true state of the battery. There are also several software updates applied by Nissan dealers that reset the BMS as part of the update. If the car is showing less than 12 bars, then it is not likely that it has been reset. The AHr reading stays constant, even with a reset, so checking with LeafSpy is the only way to know for sure on a 12 bar car.

Re: 2011-2012 HV battery reset

Posted: Wed Sep 28, 2016 4:19 pm
by AntronX
I am pretty sure Ah gets reset also. Here are screenshots from Leafspy before and after battery reset via special dealer tablet computer (Consult?).

Image

Re: 2011-2012 HV battery reset

Posted: Wed Sep 28, 2016 8:22 pm
by jkline
Just what is fraudulant about selling a used car that shows battery loss?

Re: 2011-2012 HV battery reset

Posted: Wed Sep 28, 2016 9:52 pm
by cwerdna
jkline wrote:Just what is fraudulant about selling a used car that shows battery loss?
Nothing. The fraud is with resetting the BMS so that it looks like it still has all 12 bars or that it has more than it had before the reset.

http://daveinolywa.blogspot.com/2014/11 ... -read.html has pointer to an example of a reset.

It takes awhile before the BMS relearns the battery and the # of capacity bars is accurate again.

Re: 2011-2012 HV battery reset

Posted: Thu Jun 07, 2018 10:15 am
by Umpa
For everyone else - Does resetting the BMS allow the car to drive more miles on a charge given it does not throttle the charging ?

If so then I don't see any harm in owners with paid batteries doing it.

Re: 2011-2012 HV battery reset

Posted: Thu Jun 07, 2018 10:42 am
by davewill
electromotive wrote:Has anyone else noticed the growing number of used LEAFs offered for sale with 10, 11, and 12 capacity bars? This is fraudulent activity and California authorities may want to investigate.
Thank you to anyone that responds with his/her thoughts on this matter.
Big assumption. Cars from some places don't degrade rapidly, and a number of those cars will have had battery replacements, so those cars are probably legitimate. However, I do think that battery status (age, capacity) may ultimately need to be disclosed in a way similar to odometer readings.

Re: 2011-2012 HV battery reset

Posted: Thu Jun 07, 2018 10:44 am
by goldbrick
Umpa wrote:For everyone else - Does resetting the BMS allow the car to drive more miles on a charge given it does not throttle the charging ?

If so then I don't see any harm in owners with paid batteries doing it.
No extra range is gained since the battery only has whatever capacity it has. The charging circuity will still limit the current flow in/out of the battery and the max/min voltage it allows the battery to reach. Resetting the BMS does nothing except corrupt the firmware that calculates and indicates the available battery capacity.

Re: 2011-2012 HV battery reset

Posted: Tue Oct 13, 2020 10:56 am
by Umpa
goldbrick wrote:
Thu Jun 07, 2018 10:44 am
Umpa wrote:For everyone else - Does resetting the BMS allow the car to drive more miles on a charge given it does not throttle the charging ?

If so then I don't see any harm in owners with paid batteries doing it.
No extra range is gained since the battery only has whatever capacity it has. The charging circuity will still limit the current flow in/out of the battery and the max/min voltage it allows the battery to reach. Resetting the BMS does nothing except corrupt the firmware that calculates and indicates the available battery capacity.
Well - here is what actually happens.. There are 3 levels of LBC reset, you can reset the capacity bars - clear the battery degradation and clear the charge counter. You are partly correct as in no extra range is given. I was hoping that regenerative braking would be increased but alas this is also unaffected.

There is no corruption in the firmware at all, the GOM and capacity bars will return to normal in time. Some people have said that the LBC is pessimistic regarding the SOH, thus a reset does work for some, alas I cannot corroborate this as I saw no improvement at all.