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Discussion Starter · #1 ·
Apologies if this has been covered already, I couldn't see anything on the search...

Just got back from a major service, and there's finally been an update for the 4NR6A BMS, to 4NR6B!

SOH went from ~77% to ~88%

Got my 12th bar back for the time being too.

I can finally stop being jealous of you 4RN4C folks!
 

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Discussion Starter · #3 ·
But has your range increased or just the salability of your car? :devilish:
Give me a chance to test it, I've only just back from the dealers!

To be honest, I was banking on a battery replacement improving the saleability of the car, but that's out the window now, I doubt I'd hit the threshold in time. Still, if it's anything like the 4RN4C update then yes, range should have increased. The GOM estimate, as silly as it is, does seem to have increased proportionally.
 

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Leaf 30kWh, Outlander PHEV
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Give me a chance to test it, I've only just back from the dealers!

To be honest, I was banking on a battery replacement improving the saleability of the car, but that's out the window now, I doubt I'd hit the threshold in time. Still, if it's anything like the 4RN4C update then yes, range should have increased. The GOM estimate, as silly as it is, does seem to have increased proportionally.
You know the approximate daily usage and amount of electricity you add to the car? Do the usual and let us know!!


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Thats great!, just had my 2017 6a serviced a month ago but will contact the dealer, hopefully to not be told they have no record of any update!

Is it right to assume that when people quote soh %, it's based on % of the 27kwh available and not the full 30 kwh?

So 88% means 23.76kwh available? Thanks
 

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Leaf 30kWh, Outlander PHEV
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Thats great!, just had my 2017 6a serviced a month ago but will contact the dealer, hopefully to not be told they have no record of any update!

Is it right to assume that when people quote soh %, it's based on % of the 27kwh available and not the full 30 kwh?

So 88% means 23.76kwh available? Thanks
I believe all LeafSpy data is based on actual capacity so 88% of 30 kWh


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That's useful to know, I'm due a service in the next couple of months and will mention the update.
 

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But has your range increased or just the salability of your car? :devilish:
Don't you mean has Nissan managed to let itself off the hook for a SoH based warranty battery replacement? :p

Funny how when cars start getting down near the battery warranty replacement threshold a firmware update which miraculously improves the SoH is on offer ? ;)
 

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Leaf 30kWh, Outlander PHEV
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Don't you mean has Nissan managed to let itself off the hook for a SoH based warranty battery replacement? :p

Funny how when cars start getting down near the battery warranty replacement threshold a firmware update which miraculously improves the SoH is on offer ? ;)
Is a software update. All they have to do is make sure battery bars don’t drop irrespective of SoH or inflate the numbers


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Discussion Starter · #11 ·
Software updates like this and the 4RN4C update are bit of a double edged sword.

On the one hand, it's a benefit in the short term as it makes the car a bit more practical. Whether it's a correction of a genuine mistake, or just fiddling the upper and lower voltage bounds to squeeze more out of it is irrelevant, the car will go that little bit further than it has in recent months, and that is good. If it was only for the sake of warranty claims, they they would have just changed the boundaries at which the bars drop, and not correct the actual SOH and capacity of the battery. That's not to say it isn't a fiddle on their behalf, but at least there is benefit to me in the process.

In the long term, it's not great, for me at least, because my plan was to drive the car a couple more years and the stick it up for sale as soon as it had a shiny new battery in it, which may not happen now.

Either way, I've got too much other stuff going on in my life at the moment to be able to deal with the hassle of getting a new car, so I will take the short term win as a positive for now.
 

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Leaf 30kWh, Outlander PHEV
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It took 23 months for SoH to revert to pre update SoH in my 4NR4A to 4C

SoH is indicative of available capacity so fiddling with cut off voltage wouldn’t have any impact. It would allow greater cycling

Leaf30 originally had 2 kWh buffer and I think based on the the discharge curve significant amount should be at the top end

One way to make car more usable would be to enable it to charge to 4.2v (iPace did so using updates)

If we take age related degradation at 3% our Leaf has correct age SoH today (86-87%)


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It took 23 months for SoH to revert to pre update SoH in my 4NR4A to 4C

SoH is indicative of available capacity so fiddling with cut off voltage wouldn’t have any impact. It would allow greater cycling
Of course changing the cutoff voltages have an effect on the usable capacity. Lowering the lower cutoff voltage doesn't have as much effect as the upper cutoff though as the voltage slope near discharge is quite steep.
Leaf30 originally had 2 kWh buffer and I think based on the the discharge curve significant amount should be at the top end

One way to make car more usable would be to enable it to charge to 4.2v (iPace did so using updates)
Not only would charging the cells to a higher voltage reduce cycle life considerably, there is a much greater risk of thermal runaway and fire. Just ask Hyundai...

Over charging Lithium Ion cells - even by a seemingly small amount is very risky. Charging to 4.2 volts instead of 4.1 volts is about a 10% over charge.
 

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Of course changing the cutoff voltages have an effect on the usable capacity. Lowering the lower cutoff voltage doesn't have as much effect as the upper cutoff though as the voltage slope near discharge is quite steep.

Not only would charging the cells to a higher voltage reduce cycle life considerably, there is a much greater risk of thermal runaway and fire. Just ask Hyundai...

Over charging Lithium Ion cells - even by a seemingly small amount is very risky. Charging to 4.2 volts instead of 4.1 volts is about a 10% over charge.
4.2v is the upper voltage. Only cells I’ve seen get really hot (no thermal runaway) were old Sanyo cells.
Over charging refers to charging above 4.2v

Other Lithium chemistries like LTO (2.5v) and LiFePO4 (3.2v) have lower voltages

4.1v is chosen to not hit that issue and reducing overall DoD there but doubling the cycling life.


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4.2v is the upper voltage. Only cells I’ve seen get really hot (no thermal runaway) were old Sanyo cells.
Over charging refers to charging above 4.2v

Other Lithium chemistries like LTO (2.5v) and LiFePO4 (3.2v) have lower voltages

4.1v is chosen to not hit that issue and reducing overall DoD there but doubling the cycling life.


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No EV that I'm aware of charges to 4.2 volts. It's not just cycle life, it's also safety in the harsh environment of an EV.
 

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Apologies if this has been covered already, I couldn't see anything on the search...

Just got back from a major service, and there's finally been an update for the 4NR6A BMS, to 4NR6B!

SOH went from ~77% to ~88%

Got my 12th bar back for the time being too.

I can finally stop being jealous of you 4RN4C folks!
Can you remind the year and mileage of your Leaf 30?
I tried to look it up in your history but couldn't find it readily.

I'm asking because I'm looking into adding a Leaf 30 to my fleet of Leaf 24's and want to get a sense of what SOH to expect for what mileage and year.
 

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Leaf 30kWh, Outlander PHEV
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Of course changing the cutoff voltages have an effect on the usable capacity. Lowering the lower cutoff voltage doesn't have as much effect as the upper cutoff though as the voltage slope near discharge is quite steep.

Not only would charging the cells to a higher voltage reduce cycle life considerably, there is a much greater risk of thermal runaway and fire. Just ask Hyundai...

Over charging Lithium Ion cells - even by a seemingly small amount is very risky. Charging to 4.2 volts instead of 4.1 volts is about a 10% over charge.
Tesla charge all the way to 4.2V and so do Jaguar iPace.


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Discussion Starter · #18 ·
Can you remind the year and mileage of your Leaf 30?
I tried to look it up in your history but couldn't find it readily.

I'm asking because I'm looking into adding a Leaf 30 to my fleet of Leaf 24's and want to get a sense of what SOH to expect for what mileage and year.
Apr 2017, 39k on the clock.
 
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