I've had good luck with the blue 3v Tenergy RCR123a's. Been using them for over 6 months in my SB with no problems besides one set of
batteries stopped charging. Make sure to mark the batteries and keep them in pairs. I didn't have good luck with the yellow tenergy lifepo's. The blue ones seem to be more consistant for me.
There are also some AW 3.2v 16340 lifepo's floating around. I haven't tried those yet. They're a safer battery chemistry.
Whatever you do, don't get the ultrafire 16340 3v batteries, they're too big for the SB.