Combined primary and secondary units

A system for performing at least one cleaning or grounds maintenance operation, comprising:

• a primary unit having a power source and having elements configured for performing at least one cleaning or grounds maintenance operation;
• one or more secondary units, connectable to the primary unit, each secondary unit having a power source incorporated therewith, each secondary unit having elements configured for performing at least one cleaning or grounds maintenance operation, the secondary unit power source configured to receive power from or being charged by the primary unit power source;
• the primary unit power source being connectable to the one or more of the secondary unit power sources, for the delivery of power thereto or charging thereof, the primary unit having receiving means for storing one or more of the secondary units therein, the power sources of the secondary units being connectable to the primary unit power source when received therein;
• a primary controller for controlling the operation of the primary unit;
• one or more secondary controllers for controlling the operation of each secondary unit;
• wherein the primary unit power source is selected from the group consisting of a combustion engine, a fuel cell, and one or more batteries, which are capable of powering or charging the one or more secondary units connectable thereto;
• and,
• wherein the primary unit and the one or more secondary units each have a communications module which enable communication by and between each primary unit, each secondary unit, and/or an external device or system.