I have to have 2 batteries and 2 toppers with me almost every time I leave the home or office. Ego batteries, with random clearos - T3's, ProTanks, EVODs.
My PLAN is, one of these months if I get a bonus, to see if a ProVari Mini is compact enough for my suit pocket - otherwise when I get it, that'll stay home like my VAMO and SVD.