US Patent 6938400 Electric drive mower with trailed auxiliary power source

Provided is an all-electric riding greens mower. The mower includes a frame which is supported for movement upon a plurality of ground engaging wheels and upon which are supported a modularly interchangeable power source and a plurality of reel lawn mowers. An electric motor provides driving torque to enable movement of the mower between and over golf course greens or other surfaces to be mowed, electric motors provide driving torque for each of the reel lawn mowers. The interchangeable power source provides electrical energy for driving the electric motors, including the primary mover and the electrical motors for the reel type lawn mowers. The modularly interchangeable power sources may comprise a bank of batteries, a motor/generator set, a fuel cell, or a combination of these. The power source may be easily exchanged in the field for another, freshly charged power source. Exchange occurs using either a fixed change stand or a mobile change stand. The change stands are configured to facilitate exchange by reducing friction caused by the generally weighty power source. The power source is delivered to the fixed stand on towable trailers.