How do you guys do it? I carry my provari around as a back up to my mech and check that way but its always a hassle unscrewing and screwing top/bottom caps. im also limited to checking 18650/18490 sized batteries. my fav size is 18350 but i have no way of checking w/o a multimeter. i could carry that too but thats a bit big. are there any portable options for a battery-life meter?