Method and system of charging multi-cell lithium-based batteries

A method of charging a battery using a battery charger, a first battery having a Lithium-based chemistry, the first battery having a first nominal voltage in a first nominal voltage range, a second battery having a Lithium-based chemistry, the second battery having a second nominal voltage in a second nominal voltage range, the second nominal voltage being different than the first nominal voltage, the second nominal voltage range being different than the first nominal voltage range, the battery charger being operable to charge the first battery and the second battery, said method comprising the acts of:

• electrically connecting the battery charger and the first battery;
• charging the first battery via a pulse charge;
• electrically connecting the battery charger and the second battery;
• and
• charging the second battery via a pulse charge.

A battery having a Lithium-based chemistry, the battery having a nominal voltage in a nominal voltage range, the battery comprising:

• a plurality of battery cells, each cell in the plurality having a Lithium-based chemistry;
• a chemistry identification component indicative of the chemistry of the plurality of battery cells;
• and
• an identification component indicative of one of the nominal voltage and the nominal voltage range of the battery;
• wherein the battery is operable with an electrical device, power being transferable between the battery and the electrical device, the chemistry of the battery and the one of the nominal voltage and the nominal voltage range of the battery being identifiable by the electrical device.

An electrical combination comprising:

• a first battery having a first plurality of battery cells, each cell in the first plurality having a Lithium-based chemistry;
• a second battery having a second plurality of battery cells, each cell in the second plurality having one of a Nickel-Cadmium chemistry and a Nickel-Metal-Hydride chemistry;
• and
• a battery charger operable to charge the first battery and the second battery via pulse charging.

An electrical combination comprising:

• a first power tool operating in a first voltage range;
• a first battery having a first plurality of battery cells, each cell in the first plurality having a Lithium-based chemistry, the first battery having a first battery nominal voltage in a first nominal voltage range, the first battery operable to power the first power tool;
• a second power tool operating in a second voltage range, the second voltage range being different than the first voltage range;
• a second battery having a second plurality of battery cells, the total number of cells in the first plurality being different than the total number of cells in the second plurality, each cell in the second plurality having a Lithium-based chemistry, the second battery having a second battery nominal voltage in a second nominal voltage range, the second battery nominal voltage being different than the first battery nominal voltage and being outside of the first nominal voltage range, the second battery being operable to power the second power tool;
• and
• a battery charger operable to charge the first battery and the second battery.

An electrical combination comprising:

• a first battery having a Lithium-based chemistry;
• a second battery having a chemistry other than a Lithium-based chemistry;
• a first power tool operable to be powered by at least one of the first battery and the second battery;
• a second power tool operable to be powered by at least the other of the first battery and the second battery;
• and
• a battery charger operable to charge the first battery and the second battery and having a control circuit, the control circuit operable to provide charging current to both the first battery and the second battery in a pulse mode.