WE CLAIM:
1. A charging station (14) for charging an electrically powered
vehicle (12) comprising one or more energy storage devices (16) and a vehicle
control circuit (20) having a pilot diode (22), the charging station (14) comprising:
a power source (36) useable to provide recharging power to the one or more energy storage devices (16) on the electrically powered vehicle (12); and a charging device (38) configured to control energy transfer from the power source (36) to the electrically powered vehicle (12), the charging device (38) configured to:
provide a control pilot signal to a vehicle control circuit (20) of the electrically powered vehicle (12), with the control pilot signal being received by the vehicle control circuit (20) upon connection of the electrically powered vehicle (12) to the charging station (14);
measure a voltage level of the control pilot signal upon connection of the electrically powered vehicle (12) to the charging station (14);
perform a selected pre-charge testing routine based on the measured voltage level of the control pilot signal; and
enable charging of the electrically powered vehicle (12) from the power source (36) upon compliance with the selected pre-charge testing routine that was performed.
2. The charging station (14) as claimed in claim 1 wherein the
charging device (38) is further configured to:
determine a charging state associated with the electrically powered vehicle (12) based on the measured voltage level of the control pilot signal;
perform a first pre-charge testing routine if the voltage level of the control pilot signal is at a first voltage level or a second pre-charge testing routine if the voltage level of the control pilot signal is at a second voltage level; and

enable charging of the electrically powered vehicle (12) from the power source (36) upon completion of and compliance with the one of the first pre-charge testing routine or the second pre-charge testing routine that was performed.
3. The charging station (14) as claimed in claim 2 wherein the first voltage level is approximately 9V, with the approximately 9V voltage level of the control pilot signal indicating that a switch (28) is present in the vehicle control circuit (20) and is open.
4. The charging station (14) as claimed in claim 3 wherein the first pre-charge testing routine comprises a pilot sequencing test following a state A --> state B --> state C sequence, with the voltage level of the control pilot signal varying between each state.
5. The charging station (14) as claimed in claim 4 wherein, in performing the pilot sequencing test, the charging device (38) is configured to:
oscillate the control pilot signal provided to the vehicle control circuit (20), with the oscillating control pilot signal causing the switch (28) in the vehicle control circuit (20) to close;
measure the voltage level of the control pilot signal upon closing of the switch (28) in the vehicle control circuit (20);
cause contactors (51) in the charging device (38) to close if the voltage level of the control pilot signal is at a third level, so as to enable charging of the electrically powered vehicle (12) from the power source (36);
otherwise declare a fault condition and disable charging of the electrically powered vehicle (12) from the power source (36).
6. The charging station (14) as claimed in claim 5 wherein the third
voltage level is either approximately 3V or approximately 6V.

7. The charging station (14) as claimed in claim 2 wherein the second voltage level is approximately 3V or approximately 6V, with the approximately 3V or 6V voltage level of the control pilot signal indicating that the vehicle control circuit (20) comprises a simplified vehicle control circuit (20) that lacks a switch therein.
8. The charging station (14) as claimed in claim 7 wherein the second pre-charge testing routine comprises a pilot diode (22) test following a state A --> state C sequence, with the voltage level of the control pilot signal varying between each state.
9. The charging station (14) as claimed in claim 8 wherein, in performing the pilot diode (22) test, the charging device (38) is configured to:
provide a control pilot signal to the vehicle control circuit (20) having a voltage of -12V;
measure the voltage level of the control pilot signal responsive to the providing thereof to the vehicle control circuit (20);
oscillate the control pilot signal provided to the vehicle control circuit (20) and cause contactors (51) in the charging device (38) to close if the voltage level of the control pilot signal remains at approximately -12V;
otherwise declare a fault condition and disable charging of the electrically powered vehicle (12) from the power source (36).
10. The charging station (14) as claimed in claim 9 wherein the charging device (38) is configured to oscillate the control pilot signal at a duty cycle equivalent to a 16A charging level.
11. The charging station (14) as claimed in claim 2 wherein the charging device (38) is configured to declare a fault condition and disable charging of the electrically powered vehicle (12) from the power source (36) if the voltage level of the control pilot signal is not at either of the first voltage level or

the second voltage level upon connection of the electrically powered vehicle (12) to the charging station (14).
12. The charging station (14) as claimed in claim 1 wherein the
charging device (38) comprises:
a state drive circuit (46) configured to generate the control pilot signal;
a detection circuit (48) configured to measure the voltage level of the control pilot signal responsive to the providing thereof to the vehicle control circuit (20); and
a processor (44) programmed to provide commands to the state drive circuit (46) to control generation of the control pilot signal and enable and disable charging of the electrically powered vehicle (12) from the power source (36).
13. A method of pre-charge testing for authorizing use of an electric
vehicle charging station (14), the method performed by a charging device (38) of
the electric vehicle charging station (14) and comprising:
providing a control pilot signal to a load (12) upon detecting connection thereof to the electric vehicle charging station (14);
determining a state of a load charging cycle based on the control pilot signal, the load charging cycle comprising at least a State A, a State B, and a State C each defined by a different control pilot signal voltage level;
performing a pilot sequencing test if the charging cycle goes from State A to State B upon connection of the load (12) to the electric vehicle charging station (14);
performing a pilot diode (22) test if the charging cycle goes from State A to State C upon connection of the load (12) to the electric vehicle charging station (14); and

enabling charging of the load (12) from the electric vehicle charging station (14) upon completion of and compliance with the one of the pilot sequencing test or the pilot diode (22) test that was performed.
14. The method as claimed in claim 13 wherein the charging cycle is at
State B when the control pilot signal voltage level is at approximately 9V, the 9V
control pilot signal voltage level indicating that the load (12) comprises a vehicle
control circuit (20) including a switch (28) in an open state, so as to provide for
charging of the load (12) at a 16A or greater charging level; and
wherein performing the pilot sequencing test comprises:
oscillating the control pilot signal provided to the vehicle control circuit (20), with the oscillating control pilot signal causing the switch (28) to close;
measuring the control pilot signal voltage level upon closing of the vehicle control circuit switch (28);
causing contactors (51) in the electric vehicle charging station (14) to close if the measured control pilot signal voltage level is at approximately 6V upon closing of the vehicle control circuit switch (28), so as to enable charging of the load (12);
otherwise declaring a fault condition and disabling charging of the load (12) via the electric vehicle charging station (14).
15. The method as claimed in claim 13 wherein the charging cycle is at
State C when the control pilot signal voltage level is at approximately 6V, with
the 6V control pilot signal voltage level indicating that the load (12) comprises a
simplified vehicle control circuit (20) with no switch therein when the load
charging cycle jumps from state A to state C and indicating that the load (12)
comprises a vehicle control circuit (20) including a switch (28) in a closed state
when the load charging cycle goes from state B to state C, so as to provide for
charging of the load (12) at a 16A or greater charging level; and
wherein performing the pilot diode (22) test comprises:

providing a control pilot signal having a voltage of -12V to the load (12);
measuring the control pilot signal voltage level responsive to the providing of the -12V control pilot signal;
oscillating the control pilot signal and causing contactors (51) in the electric vehicle charging station (14) to close if the control pilot signal voltage level remains at approximately -12V;
otherwise declaring a fault condition and disabling charging of the load (12) via the electric vehicle charging station (14).