If you're out on a shoot in a situation with no access to a power outlet, you've got a handful of options to get you through. First I guess is to stick with available light, which I tend to do a lot, however you're at the whim of the sun. Second is to use speedlights, which are surprisingly capable as people like David Hobby have shown with his Strobist zeitgeist. They do have limits on their power however which makes shooting them into a 4 foot octabox less practical. So what do you do if you need a big powerful light in the middle of nowhere? Well on really big shoots you could use a generator, but the cool way to do it is with battery powered studio strobes.
I've owned and used a Profoto AcuteB pack and head for a couple of years now. The light out of it is typical Profoto beautiful and smooth, and it's simple well as relatively compact to boot. The problem is that I don't use it very often and I think the lead acid battery is dying on me. Honestly, I get maybe 100 pops at half power (on a 600ws light) before it starts complaining by slowing down recycle times and beeping to tell me I'm going too fast.
Well last night I went to shoot a ukulele player I know up on a midtown roof at sunset. I needed to balance the light from the remaining sun on the buildings behind him with a big soft light source on Paul. Normally this would be a job for the Acute, but Dan came along with me and instead brought a 1600ws White Lightning head and his recently aquired Paul Buff Vagabond Mini battery. And I'll get right to the point, this little thing blew me away.
I shot over 300 shots with the light around half power into a big octabox about 8ft away from the subject and the little thing didn't even flinch. In fact when we were all done it was still somewhere between 50%-75% charged. And it's only $240. Granted, you still need to buy a light to use it with, but even with that taken into account it's still less than a third of what you'd pay for the Profoto which in my experience can't hold a candle to the versatility of the Vagabond.
Is the light from the White Lightning strobe quite as nice as the Profoto head? Maybe not exactly as nice, but still pretty great, and the Vagabond has two outlets so you can plug in two lights to one battery where the AcuteB can only power one head. They even say you could use a power strip and go up to 4 lights which is just insane from something the size of a brick that weighs 3.5 pounds.
I'm honestly considering selling the Acute and buying one of these. It was really that great. The only downside I see is that you're now carrying a battery pack and the monolight vs a pack and lightweight head. But that's a bit of a 6 of one kind of thing. And your clients may not be quite as impressed as if it said Profoto or Broncolor on the side, but the results should make up for it and your wallet will thank you.
By the way, I have no affiliation with the Buff people, I just think this product is amazing. Though if they sent me one as a thank you, I might just keep it.