and over very long distances most of the time, shooting with 300mm, 400mm, 500mm and even the 600mm. Do you have those lenses to need such extra power for the distances and/or as large as possible DOF?. I don't. I want them for my next African Safari but don't need them for weddings and other normal work. Although I've felt some envy of the photojournalists using an auxiliary battery pack, for a wedding I really don't need it. Fresh lithium batteries can give out some 200 flashes and always carry spares to change them as soon as recycling times get longer than you want.
I own the Quantum Turbo battery pack. I simply adore it. I use it with Lithium batteries-Yes the Nikon flash units still require batteries even with the battery pack... I opt for the lithiums because one time I left alkaline batteries in an SB-24 and they leaked... I was able to get things neutralized ~$20 by a shop and since, have never had that problem. I agree with JRP the lithiums have a long life span compared to alkalines and depending on the range you'll be covering with the flash and how many exposures you'll be making, you might not need the added expense, weight, cord connections and charging time the battery requires-before and after using it. I've simply lost track of how many weddings I can shoot generally exposing anywhere from 540-720+ images per wedding before I have to change the lithiums. I can assure you that over the course of the wedding day, the Quantum Turbo pack has NEVER run out of juice on me. Since I only bought mine 03/2001 and doing a wedding a weekend since, I might not have put the kind of miles on it you intend to. One thing is for sure speaking with other wedding photographers, they do need to be serviced from time to time too, although mine hasn't needed it yet As I originally stated, I adore it. This season I intend on using rechargeable batteries in the flash unit while using the Quantum Turbo and I can let you know how that goes for an entire day of wedding photography shooting. If you're constantly changing batteries because you're running out of juice, try using the Lithiums, if you continue to have to change batteries while in the field, then I'd look into the Quantum Turbo. I've put a strap around mine and carry it over one shoulder. Best of luck on your decision.