...If I go to a 30kWh version at https://iaspub.epa.gov/otaqpub/display_ ... 671&flag=1
I see Recharge Event Voltage = 240 and Recharge Event Energy (kiloWatt-hours) = 31.7807
. I assume this means a new 30kWh Leaf when charged to 100% from a low SoC (turtle?) should take about 31.8 kWh. At lower SoH the charge time should reduce so overheads should be a similar ratio so this could be a viable method to check SoH.
Does anyone know the details of these tests and what is the starting SoC?
These test results are submitted by manufacturers, and there seems to be no extrinsic information on test procedures available.
As I posted previously re the "30 kWh" LEAF epa test results above, with my best guess
on available capacity and efficiency:
...Here is my post from several months ago, to which none of the "30 kWh" pack owners ever replied:
If you want to find actual capacity loss on a "30 kWh" LEAF, I'd suggest you test your pack the same way you would for a "24 kWh" pack, albeit with far fewer of the test parameters and variables known, and with only a single (?) "30 kWh" pack having been tested by a high-integrity source.
The EPA test of a 2016 "30 kWh" LEAF (strangely...) shows the same 31.7807 kWh from a 240 volt EVSE required to recharge after both the city (UDDS) and highway cycle tests.
This could correspond to a ~30 kWh (total) pack, that is ~90% accessible, and recharges at ~85% average efficiency over the entire accessible capacity.
Monitor the kWh your pack accepts (and/or the charge time, and voltage) after similar depletion from fully-charged (240 V) pack, after a similar single-event full (to stop) discharge.
Results should be expected to vary a great deal with pack and ambient temperatures, which I don't know for the EPA tests...
In "24 kWh" LEAF pack tests, there is significant variation in charge accepted even for the same pack, in identical tests.
This is evidently due to the LBCs inaccuracy in determining the upper and lower charge limits.
You should expect the same in the larger packs, so do not expect a single test to be determinative...
edatoakrun wrote:What is your source for, and definition of, "charging efficiency of nominally 88% at 230V and 16A."?
The 88% value a guess based on several documents. The one at https://avt.inl.gov/sites/default/files ... 12Leaf.pdf
for the older Leaf is one example...
Have you looked at all the AVTA documentation on 2011-15 LEAFs?https://avt.inl.gov/vehicle-make/nissan
I think you may agree that total (grid-to-road
) efficiency for "24 kWh" LEAFs is usually
significantly lower than 88%.https://avt.inl.gov/sites/default/files ... 12Leaf.pdf
I estimate that my 2011 pack has an efficiency range of about 88% (40 C pack temperature, recharging to "80%") to about 82% (recharging to "100%", at ~0 C), which corresponds pretty well to the multiple AVTA test results, which, IMO, seem to me to generally show about 83% to 85% efficiency for a "100%" recharge at moderate temperatures.
Efficiency certainly should also be expected to decline as a pack degrades, but that does not seem to be significant factor for my pack... yet
One major issue is that "efficiency" is really a misnomer when discussing the ratio of kWh accepted/expended in a BEV like the LEAF with passive thermal management, not utilizing an auxiliary battery pack heating system.
A cold battery has lower "efficiency", because energy is utilized to warm the pack to a (desirable) higher operating temperature range.
A warmer pack has much higher "efficiency", as well as higher capacity.