Li-ion batteries have almost zero memory effect. They do lose about 2% of charge per month. Hence my comment about a top-up charge every 6 months so that the tool is ready for use at all times.
Remember that these newer impact wrenched have Li-ion batteries.
Nicads and Nimh, yes that would have been the case but even then my comment about longevity of quality batteries applies.
I tend to check capacity by fully charging and then controlled discharging until depleted whilst measuring discharge current or voltage.
