Battery charger and method of charging a battery

An electric-vehicle charger comprising:

• a card reader configured to enable the charger;
• a variable-frequency generator configured to input electrical power and output a first alternating current of a controllable frequency;
• a digital controller configured to control said variable-frequency generator, the control including at least control of to frequency of said first alternating current;
• a first transformer configured to change the voltage of said first alternating current to a second alternating current;
• a rectifier configured to convert the second alternating current to a direct-current output;
• a multi-pin connector configured to connect to an electric vehicle and deliver the direct-current output to the vehicle.

A vehicle comprising:

• a variable alternating-current power supply configured to input electrical power and output a first alternating current of a controllable power level;
• a digital controller configured to control said power supply, the control including at least control of the power level of the first alternating current;
• a foil-type first transformer configured to change the voltage of the first alternating current to a second alternating current;
• a rectifier configured to convert the second alternating current to a direct current and
• at least one battery configured to store the direct-current output.

A method of charging at least one battery comprising at least the steps of:

• measuring the substantially open-circuit voltage of the at least one battery;
• using the substantially open-circuit voltage, selecting a first powers level for charging the at least one battery;
• starting to charge the at least one battery at the first power level;
• measuring the charging voltage and the charging current;
• increasing the charging power level until at least one of a current lid and a voltage lid is exceeded, the voltage lid being based on the open-circuit voltage;
• and
• charging until a current threshold is reached.

A method of charging at least one battery comprising in the following order the steps of:

• starting to charge the at least one battery at a first power level;
• measuring a charging voltage and a charging current;
• increasing a charging power level and a frequency until at least one of a current lid and a voltage lid is exceeded;
• and
• charging substantially at the voltage lid.