US Patent 11540429 Battery charger

A battery charger includes a housing having support structure for simultaneously supporting at least two batteries of different types for charging including a first battery of a first type and a second batter of a second type. The battery charger further includes charger electronics supported by the housing and operable to output charging current to charge the first battery and charging current to charge the second battery. A fan is operable to cause air flow through the housing. A fan speed of the fan is adjustable based on a temperature of the battery charger (i) while at least one of the at least two batteries is coupled to the battery charger for charging and (ii) while no batteries are coupled to the battery charger for charging.