I believe that LeafSpy simply reads the 'SOH' value from the CAN bus and reports it. Also, AFAIK, there is no official Nissan documentation available to the general public that defines exactly what SOH means although the overwhelming evidence supports the conclusion that it is the percentage of original battery capacity left.
RustyShackleford wrote: ↑
Fri Aug 16, 2019 11:30 am
Is it necessary to occasionally charge to 100% so it can see how many GIDs the battery can hold ?
Not really. SOH readings vary day to day and probably depend on temperature among other things. SOH will give a good estimate of the battery capacity and that is probably as good a measurement as you're going to get. If you want to do science experiments then charging to 100% to measure capacity might be more accurate but personally I wouldn't bother since charging to 100% often just increases the risk of extra degradation vs using smaller charging cycles.
There are some reports that say SOH goes up after L3 charging sessions. Whether this is an actual improvement in battery health or just an adjustment in the SOH reading is anyone's guess. My guess is that it's the latter.