Suggestion regarding batteries. Buy the AW protected batteries as recommended by the designer.
Aside from proper fit and consistent quality, the battery built in low voltage level cutoff circuitry is of added importance both because the BB uses stacked batteries, and the BB doesn't have a low voltage cut off circuit. In AW I trust.
I am impressed with the battery life the BB provides with AW Li ion batteries. I leave the house with a fresh pair, and another pair in my pocket...inside a plastic battery case of course. Extra batteries are about the size, and familiar feel of a Zippo so no hassle there. Two pair and I'm good for a day of chain vaping. After work, I put those sets on the charger, and pop in a fresh pair for the evening.
Oh, and buy at least three sets of batteries. If you have only two pairs, and only one battery fails, or you forget to charge a pair, then your forced to make do with another PV for a while.