No advise, I don't even have one... But it seems two factors. One, it is more than a box. The battery pack also provides its power converter that changes the 8x1.3 = 10 volts to about 325 volts to directly recharge the flash capacitor in a second or so. But two, the Nikon brand price does get your attention (on any item), and the other several models can do the same job for maybe 1/4 the price. It would tempt me. But I really have no issue with just the four Eneloops.