>>>I take no responsibility for you "bricking" your car for your not wiring things properly. <<<
Designing an EVSE, or charger as some say, is a great learning experience as well as having control of the form factor make it well worth the time and trouble to make one.
>>>READ THE ENTIRE INSTRUCTABLE BEFORE YOU TRY TO BUILD THIS!!!<<<
I also assume that you know how to work safely, and how to wire things in reference to a schematic.
Step 1: Tools and Supplies
J1772 EVSE control board - Open EVSE project (should be in Google Code, and they have great diagrams for EVSEs.)
J1772 Plug & Cord assembly - TucsonEV
Contactor/Relay/SSR - Electrical Supply
Box - Home Depot
12v PSU - Electronics Shop
Strain Relief for J1772 cable assembly - Electrical Supply
CR Magnetics 8420-1000-G - DigiKey
Heat-shrink tubing - Electronics Shop
Micro Torch/Heat Gun
Step 2: A little Background
SAE J1772 is a North American standard for electrical connectors for electric vehicles maintained by the Society of Automotive Engineers and has the formal title "SAE Surface Vehicle Recommended Practice J1772, SAE Electric Vehicle Conductive Charge Coupler”. It covers the general physical, electrical, communication protocol, and performance requirements for the electric vehicle conductive charge system and coupler. The intent is to define a common electric vehicle conductive charging system architecture including operational requirements and the functional and dimensional requirements for the vehicle inlet and mating connector.