The Rencher Industries BreakerBatt uses a standard 2-pin Lemo (0B.302) connector as its power input. Any cable that can provide 10-38V and at least 2.5A can be used to power the BreakerBatt.
Since the BreakerBatt is polarity agnostic, it does not matter which polarity cable you use. Be aware that the Lemo passthrough will pass unchanged polarity through to any daisy-chained device, so make sure your cabling is correct for your other devices.
Media Blackout offers 2-pin Lemo cables here: