Recently, the major producers of construction equipment including Caterpillar, Komatsu, and Volvo CE have all started to electrify some of their machines with either hybrid or full electric drivetrains. Autonomous operation is also heavily invested because of the advances of lidar technology and control software.

However, the bottle neck of further electrification is charging process which should be fast, efficient, automatic, and tolerant to the tough working sites. Wireless charging will be an ideal solution to satisfy the requirements because it is static and no conducting surface exposed. To charge fast needs high power between 300 kW to 1 MW for the heavy machines. Charging an autonomous hauler is a frequent action and repeats 60-100 times per day or hundreds of thousands of times in the lifetime of the vehicle.

The wireless charging, based on Inductive Power Transfer (IPT) technology, enables the charging through large air gap between the charging pads and mobile machines. It is possible to realize power transfer without any human involvement and any mechanical movement. The technology is especially suitable for autonomous machines due to the static nature of IPT.  An autonomous hauler will operate day and night. The charging time should be as short as possible. The charging power will be at least 300 kW in order to charge 30-80% of the onboard batteries (about 120 kWh for a hauler with payload of 55 tons) in 10 minutes. If a short charging time (such as 2 minutes) for each duty loop of the operation, the required onboard batteries can be reduced to 20 kWh.

The wireless charging solution can be applied to other construction equipment like electric wheel loaders and electric excavators.