Frequently Asked Questions
ELIX Wireless Charging systems are designed to produce as much power as a comparable corded charger. The E8K can deliver up to 7.2 kW, similar to the capacity of a Level 2 charger. That means if your vehicle takes 5 hours to charge with a Level 2 charging station then it will take 5 hours to charge with the ELIX E8K.
Other ELIX systems, like the E3K (3.3 kW) and E22K (22 kW) will charge at different rates, depending on the battery size of the vehicle. The E3K is designed for smaller batteries and smaller vehicles, while the E22K is designed for higher charge rates, larger batteries, and larger vehicles. They will still take the same time to charge as a comparable-power plug-in charging system.
Plugging in a vehicle is easy when there is only one vehicle that plugs into one charger (for instance at home) and when the weather is pleasant or you are in your own garage. As EVs gain market share, however, it is not always so simple as “plug in when you get home”. Owners may not have home charging, there may be multiple vehicles competing for the same charging space, the cable charger may not be easily accessible, or the environment may not make it desirable to stand outside to wait for the charging station to process your card. Any EV driver can appreciate how public charging has more potential problems than home charging. Additionally, car-share and EV fleets may find it desirable to eliminate any requirements for their users to interact with charging hardware. Finally, a self-driving car still needs to be charged but it is not capable of using a cable charger.
Plugging in an Autonomous Guided Vehicle, on the other hand, is more than just about thirty seconds to plug in. Firstly, it means someone may need to be paid to manage the charge. Secondly, it means that a vehicle needs to be out of service until it can recharge. Either that is a short time with an expensive and bulky fast charger, or a long time with a cable charger. It may be a complex mechanical alignment system to account for tolerances and maintain a solid connection. Either way, it is time that the vehicle can not be used. With wireless charging, though, vehicles can be designed to quickly regain a small amount of charge every time they reach a place where they stop. If they come to a depot ten times a day, that’s ten chances to recover power. That’s less time at the end of the shift to charge, and it’s more operational uptime for the vehicle.
We see wireless EV charging as much more than just not needing to plug in a cable, it is an enabling technology that makes the process of charging an EV seamless and effortless. It is about providing a way to allow EVs to always charge, even if there is no driver present. It is a part of a larger evolution of transport that could have the potential to reshape our mobility.
ELIX WPT technology is based on Magneto-Dynamic Coupling (MDC) where wireless power is transferred via the coupling between a primary (transmitter) magnet and a secondary (receiver) magnet, when the two magnets are separated by an air gap. The secondary magnet is typically a permanent magnet that moves in response to the changing field produced by the primary magnet. The motion of the secondary magnet induces an electrical current in the nearby receiver windings. This output frequency from the receiver corresponds to the frequency of the coupling magnetic field and is usually in the high 10’s to low 100’s of Hz.
In contrast, inductive and resonant inductive charging are based on two coils separated by an air gap whereby the primary coil (transmitter) directly causes high-frequency electromagnetic induction in the secondary coil (receiver). The high frequency is needed to achieve sufficient coupling in a reasonably-sized device across a reasonable gap. High frequency operation requires more complex control strategies and capacitive components.
Some people may also be concerned about the safety of radiating fields in the 10’s of kHz, although current safety standards do allow for electromagnetic field exposure in both frequency ranges, however in the 100 Hz range of MDC the effect of a specified magnetic field on the body is determined to be less.
The low operating frequency of the ELIX MDC system does not heat nearby objects as much as a high-frequency inductive field will, meaning that there is no risk of fire or damage from foreign objects in the charging region.
Yes, ELIX WPT technology is safe to human exposure as it has a much lower operating frequency than induction charging systems. In the operating region, the electromagnetic field radiation is below the ICNIRP (2010) limits. The ELIX system produces only slightly more magnetic field than a similarly sized electric motor such as you would find in any industrial or residential setting.
The maximum gap depends on the strength of the magnetic coupling between the primary magnetic and secondary magnetic fields. WPT can be achieved with gaps up to 30cm however the optimal gap for MDC in vehicles is between 8-10 cm between the transmitter and receiver cases.
The noise level of the E1K is about 65 dB at 1 meter away from the installed system. The target goal of the E8K is a noise level at or below 65 dB.
The ELIX system is quite robust to any misalignment between the transmitter and receiver. The system works with misalignment in both the X (forward-backward) and Y (left-right) axes, as well as when the receiver is tilted horizontally. The amount of misalignment is different for each of these axes, but in general a up to 10 cm is allowed in the X and Y directions as well as a +/-10 degree tilt.
The Z-gap of the system is designed to be 8-10cm, however this does not affect the ground clearance of the vehicle as the transmitter is designed to be built into a parking block above the pavement.
If the system is misaligned, the total power output of the MDC receiver is reduced and the amount of the reduction is dependent on which axis is misaligned. The total system efficiency does not reduce with misalignment, including increased Z-gap.
The operating temperature depends on the components used. Practical minimum and maximum operating temperatures are -40oC and 80oC with the maximum operating temperature limited by the permanent magnets and cooling available.
ELIX MDC systems are designed with passive cooling in mind and typically do not need to be connected to a cooling loop. The E22K is designed to be liquid cooled but is designed to be connected to the vehicle’s cooling system.
The technology is fully capable of working in outdoor environments in rain and snow as well as in an underwater environment. The MDC system has been tested in cold weather and has been installed on vehicles operating in different day-to-day driving scenarios including emergency response vehicles.
If the WPT receiver is mounted above the ground clearance of most vehicles, the receiver will not pick up any ferromagnetic objects. In most vehicles, the receiver can be mounted inside body panels that will also protect against ferromagnetic objects. As well, the MDC system automatically clears foreign objects during operation.