There are different capacities available for charging stations. Obviously the lowest level is a Level 1 which plugs into a standard receptacle and will draw a maximum of 12 amps @ 120V. Well, to be precise the charging station or EVSE tells the car that it's allowed to draw up to 12 amps and the charger built into the car abides by this restriction.
Most commonly available Level 2 charging stations are in the 20-30 amp range. Often they're marketed with the 80% current derating in mind. For example I own a Clipper Creek LCS-25 station, which is designed for a 25 amp breaker (30 in my case) and it tells the car it can draw up to 20 amps. I drive a Chevy Volt which maxes out at 3300 watts, or about 13A @ 240V. Similarly, a Clipper Creek CS-40 is designed for a 40A circuit and will tell the car to draw no more than 32A.
The J1772 charging port on electric cars has a designed current capacity of 80 amps. As such, the largest EVSE available requires a 100A circuit. As of right now the only car that can make use of such a connection is a Tesla with the dual onboard charger option. The only units I'm aware of are the Tesla HPWC and the Clipper Creek CS-100
Beyond that you're looking at a DC Fast Charger, which takes 150amp 120/208 and converts it to 400 VDC and dumps it straight into the car's battery via a dedicated connector. They also cost about $20k and up.
