Universal battery charger and method

An apparatus for rapidly charging a battery comprising:

• temperature sensing means, coupled to the battery, for sensing and producing a signal responsive to a temperature of the battery;
• signal means, connected to the temperature sensing means, for providing a signal representative of a rate of change of the temperature;
• charge control means, connected to the signal means and including first and second charging circuits, the first charging circuit being adapted to charge the battery at a first rate when the signal from the signal means is below a predetermined amplitude, the second charging circuit being adapted to charge the battery at a second rate when the signal is above the predetermined amplitude,
• wherein:
• a docking station having a docking bed and exposed contacts in the docking bed contains the signal means and the charge control means and
• a docking tray, adapted to releasably engage the docking bed, receives the rechargeable battery, contains the temperature sensing means, and provides electrical connections and electrical circuits from the battery to electrical contactors that engage a plurality of the exposed contacts to connect the first charging circuit to the battery and the second charging circuit to the battery and thereby to determine the first and second charging rates for the battery when the docking tray is engaged with the docking bed of the docking station.

A method of charging a battery with a charger including a main charger body with charging circuitry having elements usable for charging a plurality of batteries of different types and sizes, the method comprising the steps of:

• engaging a docking tray with a docking bed of the main charger body to engage contactors exposed on the tray with contacts exposed on the bed and connected to the circuitry of the main charger body, the tray including charging circuitry complementary to the circuitry of the main charger body and selected to determine charging parameters for charging a battery of a particular type and size;
• connecting the battery to be charged to the charging circuitry of the tray;
• and
• executing an automatic charging process.

A method of rapidly charging a battery comprising the steps of:

• sensing the temperature of the battery and producing from that sensing an electrical signal representative of the rate of change of sensed temperature;
• applying a charging current of a first level to the battery as long as the produced electrical signal remains below a predetermined value and reducing the charging current when the new electrical signal exceeds the predetermined value;
• determining the first level of charging current in dependence upon a charging parameter, the charging parameter being determined by a docking tray having a first array of contacts engageable with a second array of contacts of a charger main body, the charger main body having a docking station including a docking bed with which the docking tray engages and at which the second array of contacts are exposed, engagements of the first and second arrays of contacts occurring when the tray is engaged with the bed;
• and
• engaging the docking tray with the docking bed.