Cheap, but not well built.

I've used a version of this pack before. It worked well for maybe 20 uses, but shorted for no apparent reason after that. While it should have a charge reset function, I don't think mine worked. My opinion on battery packs is to go with the better build quality. Exploding li-pos are no fun. That said, this did the job for a while.

@monks19:

If you need something cheap check out the standard NP-F battery plates.
They accept any NP-F battery (also the cheap OEM NP-F970 ones)
and you can mount them quite easy on rigs too (with a 15mm to 1/4" clamp).

I use that solution now for about two years without any problems.
Though: You only get around 7 to 8V out of them (6.5 up to 8.2V with my batteries to be more precise).
So if you want something over that voltage, you need a DC to DC step up converter.

But most equipment accepts the voltage.
(At least nearly every LED light, DC coupler and monitor I had til now accepted it.)
Btw - I got mine here (in the UK) from:
http://www.cinegearpro.com/sony-np-battery-plate-adapter-kit.html

But just search for "Sony battery plate F970" on Ebay.
There are plenty of international dealers ^^.

Later you can still upgrade to a V-Mount base (a good one costs about 150 bucks).
And you can still use the already existing / at hand NP-F batteries with the dapter Vitaliy linked to.
Though: If you need multiple voltages, the already mentioned V-Mont solution is for sure the better choice.
But keep in mind: You should always use identical batteries on such an adapter.