Inductive Charging
The inductive charger has no direct electrical connection to the EV.
A weatherproof "paddle" provides power transfer to the vehicle
through the generation of a magnetic field. There is no
metal-to-metal contact between charge paddle and the vehicles internal
charge port. This paddle is inserted in the vehicle charging port
and provides a safe and easy-to-use system for EV charging. Charging is
terminated when the charging paddle is removed. The onboard system
prevents the vehicle from being driven while connected and bi-directional
communication ensures a safe connection.
Inductive charging systems transfer AC power by magnetically coupling a
primary winding on the supply side to a secondary winding on the vehicle
side. Current flows through the primary inductive coil, or paddle,
and the resulting magnetic flux induces an alternating current through the
magnetic field and across the secondary coil, completing the
circuit. The AC current is converted to DC for storage in the
vehicle battery.
Over time, several types of chargers and connectors have evolved and are
referenced as
GenI, GenII, and GenIII (TAL) variations. Of
these the GenI and GenII use the large inductive paddle connector (top
photo at left) and the
GenIII uses a small inductive paddle (bottom photo at left). Manufacturers can provide adapters
to transition from large to small connectors such as that shown at right.
Inductive chargers range in price from $1,500 to $3,500 due to quality,
warranty, and various user options such as programming and voice
feedback. Few vehicles have integrated the charging system
onboard such that only a cable and plug is needed (i.e. the GM EV1 onboard
120VAC extension cord). These UL listed chargers are available from
different manufacturers, in varying sizes, and in wall or pedestal
mounts. At most installations, the public will typically see Delco
Magne-Charge units with the large style paddle shown right.
The GM EV1 was one of the first EVs to utilized the inductive charging
systems and many installations were done utilizing this type of
charger. Today there are several other vehicles such as the Nissan
Hypermini EV and the Toyota RAV4.