Do you mean to replace the 9V battery?For the light kit, contact: sales@battenfieldtechnologies.com
the other is USB that is for factory use only.
Oh I see what you may be referring to now. The premium kit comes with a power cord and a remote battery pack. Both are for the lights only. The chrono does not have a connection for external power. There are 2 Connections on it. One for the cable to your phone or iPad and the other is USB that is for factory use only.