tkdbrusco said:
This is exactly what I suspected and said earlier. I bet the new lizard pack actually uses smaller cells and both are essentially the same guts.
In the OEM LiIon world (loose cells) the normal developmental path is the same form factor/package size will see incremental improvements in capacity (AH) each year. Same cost, same package.
It's a chemistry/mfg thing... not a packaging thing normally.
This does not mean that there are not occasional packaging breakthroughs, etc. Just that it's very expensive to change packaging, while the "process" part of mfg is often where improvements occur.
So my bet is similar cell size and config in Nissan packs. Just higher capacity. And if used in older leaf's, no consumer visible changes. They just don't degrade as much. And maybe have more hidden reserve.
If they expose the change with a capacity/range increase... then everyone clamors for retrofit/replacement.
I also believe this means assumptions about exposed but undocumented/unsupported engineering data (GID's, etc) may no longer be valid. I already suspect this may be the case based on 3 different 2013 leaf experiences I'm aware of.
Never underestimate the Japanese "Quality Circle" approach for process/product improvement and in year mfg/process changes. My bet is the battery capacity has slowly improved, but we won't see it surface in stated range improvements except as particular refresh periods. (Model year change, etc)
The other thing I've learned from radio engineering for LiIon/Poly cells is that the ever improving energy density may not be apparent if the protection & balancing circuitry does not expose it. Especially when there are capacity (fuel gage/GOM) type calculations. They may still think they have the old capacity. Remember, there is no direct measure of capacity of a cell except to cycle it and *accurately* measure the Voltage/Current from full to discharged. SOC is normally measured by voltage, but the capacity (AH) is derived from there based on assumptions. Yes, they can measure charge/discharge current and associated voltage curves. But most do not bother, and most current measurement approaches just estimate current drain via magnetic field as to put accurate measurement in place wastes energy (shunt based current measurement).
Some devices do not make capacity assumptions, and measure real world usage to develop those assumptions for fuel gauge usage. Others use a stated capacity model, and would never know if higher capacity batteries were installed as they don't even try to measure real world apparent capacity. Most laptop chargers/circuits are like this. My read is that Nissan has a very conservative "stated capacity/drain" approach.
As an aside, my 2015 GOM is nearly always showing 105-106 miles range at full charge. Then drops to what I'd expect once driving. And then is nearly always more conservative in projection than reality. IE: I nearly always arrive at destination with more than it projected. I don't trust any of it until I get more miles, but this is a very different behavior than we saw with the 2013.
Its a win-win!
