I believe I’ve asked this question to HKJ, and I think the reply was something like, for a good Li-Ion, the capacity-in and capacity-out (from discharged state, let’s assume something like 2.80v) should be almost equal (I have tested high-resistance old batteries where the capacity-in (charged capacity = Fast test) is notably higher than capacity-out (discharged capacity = NOR test)… the reason being with higher resistance, it needs more charging current to get it to full.

(I’ll have to check again the reason for NiMh charged capacity not exactly a good measure of discharged capacity… but maybe the reason could be that NiMh uses a different charging algorithm, and the charge current may affect when the charging termination occurs, and this will then affect “how much capacity” was charged into the battery. For instance, one could do very low trickle charge on an NiMh, and the voltage may not really increase or signal termination (NiMh battery full) depending on the charging scheme/termination characteristic. Anyway, that’s my limited understanding. Kindly correct my inaccuracies for those more knowledgeable than me…)