OK, time for an update. I charged the Vaporshark DNA fully overnight. I don't know how long it took to charge fully, but when I woke up this morning around 8:00am, the charge LED was green indicating it was fully charged. I immediately tested it to see if it would still be able to regulate down to its lowest 7W power setting with the load I have on it (a 2.1 ohm iClear 30S). It was able to do so; the resistance reading never flashed, and increasing the power setting to 7-1/2 watts made a noticeable difference in the vape.
I then proceeded to use it as my primary device all day to get some idea of battery life. It was certainly not the only device I vaped today -- I've got 5 other devices with 5 other flavors of juice on my desk and I like to switch among flavors. However I used the other devices/flavors more sparingly than ever today. I filled iClear 30S not that long after I got up, but after I'd already vaped something close to 1/2 ml on that charge. This afternoon when it got to the 1.5 ml line, I filled it again. Now just a few minutes before 9:00pm, it refused to fire anymore because the battery is too low, and it's just a hair above the 1.5 ml line. So I was able to vape a full 3 ml of juice from this tiny thing on one charge; that's with the power set to 8.0 watts.
IMO, that's darn good for such a diminutive device. Could I use this as my only device, completely untethered, from the time I get up in the morning until I go to bed at night? No, obviously not. Then again, I don't need to either. It is after all, a pass-through. You can vape it while charging it. It doesn't need a separate charger; all it needs is a standard micro USB cable and any source of USB power. That means plugging it occasionally during the day is not difficult at all.
That actually gives me a crazy idea for a modification. There are these wireless charging setups for phones....