garygid wrote:I thought that the 80 Wh was the energy applied to the battery,
and less is actually stored in the battery. Then, less than that is
available, since there are losses when extracting energy from
the battery, just as there are losses when filling the battery?
So, maybe something like 78 is stored and 76 is actually recovered for use?
Just asking TMWK (the man who knows).
The 80 value checks out perfectly against the government battery measurements. At 22.031kWh from the charger to the battery, plus the absolute likely minimum of 0.300kWh to 0.400kWh still in the battery, the total divided by 281 Gid equals 79.47 to 79.83 wattHours each.
Of course, we don't know that the government test actually showed 281 Gid. Just 280 Gid would put the value at 79.75 to 80.11. So, I'm glad we have non-Nissan lab results to back up our data.
The 21.381kWh actually recovered means there is a direct battery energy recovery loss of 21.381 / 22.031, or 97.05% efficient.
If we apply that 97.05% in this example to 80 wattHours, it becomes 77.64 per Gid for "energy from the battery during discharge".
Since they did this all in a lab at room temperature, it's perfect data to apply temperature correction factors to. But, the above example is why I chose 77.5 per Gid as the default. GIDs continue to be the gold standard for determining the only thing the end user cares about; usable capacity for range.
That usable battery capacity, with temperature correction and compensated for UNusable energy will generally align with the dash miles per kWh economy meter to get ultimate range.
The displayed kWh on the LEAF Spy app should reflect this data. Conversely, we get exactly the same ultimate result with continuing to call a Gid = 80 with a 97.05% correction factor.
Now, the app would show a 281 Gid battery at 70F temperature to have:
(((281 - 6 UNusable) * 80) * .9705 energy recovery factor) * 0% temp correction = 21.351kWh usable
Isn't is great how all that works out?
When the car is being driven at 4.1 miles per kWh, the DTE value in the app will show:
4.1 * 21.351 = 87.5 miles, or just about EXACTLY what it will actually do.LEAF battery capacities
Energy from the wall from dead to 100%: 25.414 kWh
Energy from the onboard charger to battery: 22.031 kWh (86.6% charger efficiency)
Energy from the battery during discharge: 21.381 kWh (our generic "21kWh" useable at 70F)http://www1.eere.energy.gov/vehiclesand ... 2012_o.pdfhttp://www1.eere.energy.gov/vehiclesand ... 2012_p.pdf