I used rectangular, sealed, rechargeable batteries like used for back up power for alarm systems. It's about the size of a pack of cigarettes, costs $10 or $12 each. Two of those batteries would get my SB25 through a wedding. I used larger versions on off-camera strobes -- one battery for each was more than enough for a wedding.
Battery power is cheap and easy to DIY and have it look professional. The issue is how much faster your strobe is going to recycle, how much less time is required between flashes. You could over heat you lights/strobes.
Batteries are chemistry -- chemically, they produce 1.5vdc. Depending on the chemistry (battery technology) they will be a fraction of a volt above of below that. So a 6v battery is really four 1.5v cells in series. A 12v battery is 8 cells in series. Batteries are sealed in a plastic box so you can't see the individual cells inside. But 6vdc is 6vdc, regardless of where it comes from.
Here's a battery like I used to recycle my strobes, selling for $20 at Battery Mart:
It's about the size of pack of cigs, others are bigger, lots of sizes (A/Hrs).