There are a few different ways to power those. Some ways "kinda" work, other work great.
Using one of the little SP battery boxes, with the mics terminated together, will cause clipping at loud shows. Reason is, they are not designed to be ran like that(2 wire), its just that they will handle moderate levels and its cheaper to run them that way vs. running them with phantom power, which a lot of people don't like to do because its more costly. (If you run them with phantom power, they will handle anything you can throw at them without distorting, and they will get a better response). I used to run the 829s with one of their BBs, and was not happy with the results at all (clipping,ect).
its gonna come down to how much money you can spend to put a setup together. Best way is phantom power, I'd recommend, for instance the Denecke over the AT boxes, as it sounds a lot better than they do. In any case, you're gonna need an external power supply (to do it right)