The battery packs are interconnected via soldered strips and covered with a PVC wrapping.  Two wire leads extend out of the pack.  As an option to the battery packs you can select to get connectors for the batteries.  The connectors are sometimes referred to as dean connectors.  They can be soldered/crimped onto the wire ends and offer a great way of disconnecting the batteries for charging, etc. 

Of course we sell transformers to charge your batteries along with a automotic battery tenders that will monitor your batteries charging progress and stop charging when the battery reaches peak voltage.  For chargers and transformers follow this link.