Robotics startup Revoy has created a device to allow any truck to go electric for part of its journey. The San Francisco-based company has built a detachable unit with an electric motor and batteries that sits between the truck’s tractor and trailer. ImageRevoy has built a detachable unit with an electric motor and batteries that sits between the truck’s tractor and trailer. With the new funding, Revoy is planning to assemble a less expensive second-generation electric dolly with a smaller battery offering the same range. Similarly, when the driver applies the brake, the electric dolly starts using the reversing of the electric motor to charge the battery.