Cell (LiIon) Capacity Measurement Terminal Voltage, under load or open circuit?

[sleemanj]

When measuring a, in this case, lithium-ion cell's capacity by way of discharge, is the terminal voltage (let's say 3v) determined reached under (let us assume a constant current) load, or open circuit?

My assumption would be under load as the practical choice, but the couple of datasheets I've looked at don't really make it clear and open-circuit would make for better marketing numbers...

Opinions?

[sleemanj]

Looking at some discharge charts, I've come to the conclusion that it must be at least charted as under load. 

The reason being that the charts show a lower start voltage for higher currents, so unless they are switching from under load at the start and open circuit at the end, it must be the under load voltage that determines when to finish the test.

[BravoV]

Here, suggesting to download this Sanyo/Panasonic specific document for this particular NCR18650GA cell ->  http://www.hurt.com.pl/prods/bat/_li_ion/ncr18650ga.pdf

It has much detail than ordinary Panasonic single page Li-Ion specification sheet.

Hope this clear things up.