Choices: External Power Sources
Here's the normal track for most shooters:
You start with AA's, of course. Then you want more total flash capacity, so you buy a Quantum QB1+ battery, because it costs less than the high-voltage stuff.
But since it is only a 6-volt system, so you gain no advantage on recycle time. And you are still carrying around the extra weight.
After a while, you start to resent the fact that you are carrying around the extra weight without the extra recycle speed, so you buy a hi-voltage battery and you wonder why you didn't do that in the first place.
And yes, I know there are some cool other 6-volt systems out there, too. Some garage engineer is always introducing a new 6-volt rechargeable batt. But again, it comes back to this: If you are gonna carry around the weight, you may as well bite the bullet and get the super-fast manual recycle times. They make the flashes far more versatile.
Here's the thing. The plain old AA batts are a really pretty good deal, when it comes down to it. If you work for a paper, they are normal supplies. If not, you can get them for about 20 cents each in bulk at Wal-Mart or Home Depot. They have a bad rap, if you ask me.
The Ni-MH rechargeables are okay, but they run at 1.2 volts each instead of 1.5 for alkalines. So recycle time is further hurt, and the flash thinks the batts have worn out before they actually are.
EDIT: Points taken (from the comments section) on the Ni-MH batts. They seem to be a very good choice if high-speed recycle is not important. And the batteries definitely are environment friendly, which a big plus. They are also easier on the wallet in the long term.
Apparently there is another Nikon batt pack that uses them, too, as per another comment. Although I do not know how it fits so many different SB's, some of which have different Hi-V connectors. More info would be appreciated.
Thanks much for the input, guys. And if you are not reading the comments, you are missing out on lotsa good info...
If I had it to do all over again - and it is a constant lament that I don't - I would have bypassed the heavy-duty 6-volt external packs and just used AA's for most of the time. If you are gonna be shooting a lot, stick another 4-pack of fresh batts in your pocket or waist pack. Easy, lightweight and cheap.
(You wedding guys are a different breed, of course. You need capacity, and lots of it. Quantum QB1+ battery packs may well be the best economical choice for you.)
Even now, most of the time I use AA's. I use hard light more and more these days, so I tend to hang out in the 1/16th to 1/4th power range on manual. But when I light sports - like wrestling, or hoops - I go with two high-voltage packs.
This is one reason I look for strobes that have a jack to accept a high-voltage battery pack. Having the ability to get a one-second recycle at full manual power is a great thing. (Most of the Nikon SB bounce flashes have high-voltage jacks.)
Here is my setup. I have 6 SB-style strobes (kind of like Mrs. Strobist and shoes, I guess) but only two high-voltage packs. The kind I use are ten years old and made by Lumedyne. I absolutely love them. They cost less than the Quantum Turbos. They take the beating of rattling around in my trunk. And they just go and go and go.
The current model, the Lumedyne High Voltage HV UltraCycler, is a little dressier than mine are, but the guts are mostly the same. There is a better "remaining power" meter, too. If the rechargeable batteries ever wear out, Lumedyne will rebuild them for much less than the cost of a new pack. And the batts they use in there are so good there is an 8-year, pro-rated warranty.
You'll need to get a cord to fit your flash. The connections are the same as the Quantum Turbo cords, so you can search both areas for the cord to fit your flash. But this is money well-spent that will will benefit you for years and years to come.
Much like the Pocket Wizards, you'll eventually want one of these. Hopefully, it'll be before you spend an equal amount of money going through 6-volt systems and accessories. You are probably only going to need one, even if you use multi-light setups. One light is usually doing your heavy lifting, set on full or half power for bouncing into an umbrella or ceiling. So you stick the Lumy on that flash and use AA's on the lower powered one(s).
The only exception is cross lighting basketball from the up in the stands. You'll need two batts (and Pocket Wizards) to do that effectively. Yeah, I know it is expensive. But that same setup will serve you well through all of your cool, lit environmental portraits, too.
And for you Canon shooters (who shoot with those neutered, PC-less Canon strobes) it's payback time. You have a great option. The CP-E3 compact battery pack uses AA's, Ni-Cad's, Ni-MH's, whatever. It is small and light and even comes with a cord to fit your flash for about $135. Full-manual recycle times are less than 2 seconds. Make sure it is compatible with your model. If you are going to use Canon strobes, I'd grab one (or two) of those and some Ni-MH AA's while you are there (or grab them from Wal-Mart.)
Nikon makes a similar setup. But it only fits a few of their flashes. If you shoot with SB-800's or SB-80DX's, you are in luck.