Combination lawn mower and trailer

A combination of a lawn mower and a trailer for carrying the lawn mower, (a) the trailer including at least one wheel and a generator electrically coupled to the at least one wheel, wherein when the at least one wheel turns the generator generates electricity and (b) the lawn mower including a motor and a set of wheels, wherein the motor drives the set of wheels, the combination comprising:

• a charging station affixed to the trailer, the charging station including
• a first charging circuit,
• a first battery receptacle coupled to the first charging circuit and configured for receiving a first type of battery pack, and
• a second battery receptacle coupled to the first charging circuit and configured for receiving a second type of battery pack;
• an electrical connector connecting the generator to the first charging circuit of the charging station;
• the lawn mower comprising:
• a first battery pack of the second type of battery pack housed in the lawn mower for providing electricity to the motor,
• a third battery receptacle configured for receiving the first type of battery pack, and
• a second charging circuit coupled to (a) the third battery receptacle and (b) the first battery pack;
• and
• a cable connecting the generator to the second charging circuit of the lawn mower.