Just got some extra batteries, do I need to charge before storing or store as is?
My experience, take it with a "grain of sale".
I've bought several 18650 batteries in the past 2 months and some 21700s that came with mods.
Every single one of these batteries showed a 3.5v charge right "out of the box" on my charger. So I am guessing this is what manufacturers charge them to for optimal storage.
You definitely don't want to store them at full charge (from what I've been told).