IIRC, the 3600 actually came with a kit to hardwire it to the battery (of course with a snap-off connector) when you are not using the charger. I never hooked mine up, choosing to use the aligator clips instead; however, it was a nice option.
You can see the type of cable I'm talking about on this page (1st and 2nd from the top) -
http://www.ctek.com/EN-US/Accessories.aspx
