I have 6 LG HB6 30amp batteries, married in 3 pairs, (1a,1b, 2a, 2b, 3a, 3b), they get charged together, and used together in their pairs only. Run them only in my Sig150 and my IPV3, no other devices, if I had mech dual battery, Sig150tc or Snow Wolf I'd run them in those as I am not breaking the pairs up. I've got Sony VTC4s, Samsung 25r, and several others that are used in my tube mods and other single battery mods. My HB6's only get used 1a with 1b, 2a with 2b, and 3a with 3b. Bought them all together, charge them in pairs together (1a in slot 1 and 2a in slot 3 or 1a slot 1, 2a in slot 2, 1b in slot 3, 2b in slot 3 of my Nitcore i4 battery charger, my Efest LUC4 charger, they get charged in slot 2 and 3 to keep their charging balanced, next recharge they go into the charger like 1b slot 1 and 1a in slot 3 on the Nitcore, and rotae their positions in your mod each time you use, 1a in slot 1, 1b in slot 2, next time in the mod, 1b in slot 1 and 1a in slot 2) these help keep the batteries balanced as much as possible. Married batteries become unbalanced, the stronger battery pulls more load to make up for the weaker battery, and they need the same amount of charge and discharge cycles, use one in another mod, disrupts this balance and leads to potential problems later.