Battery pack and battery charger system

A multi-voltage battery pack for use with tools of different operating voltages, the multi-voltage battery pack comprising:

• a housing comprising a plurality of slots therein,
• a first string of battery cells arranged in electrical series and disposed inside the housing, the first string having a first positive voltage terminal and a first negative voltage terminal,
• a second string of battery cells arranged in electrical series and disposed inside the housing, the second string having a second positive voltage terminal and a second negative voltage terminal, and
• an electrical device interface shaped and configured to interchangeably (1) mechanically and electrically couple with a first battery pack interface of a first power tool that is configured to operate at a first operating voltage, and (2) mechanically and electrically couple with a second battery pack interface of a second power tool that is configured to operate at a second operating voltage,
• wherein the second operating voltage is higher than the first operating voltage,
• wherein, when the electrical device interface of the multi-voltage battery pack is coupled with the first battery pack interface of the first power tool, the first and second positive voltage terminals are electrically connected to each other and the first and second negative voltage terminals are electrically connected to each other such that the first and second strings are electrically connected to each other in a parallel configuration so as to provide the first operating voltage to the first power tool,
• wherein, when the electrical device interface of the multi-voltage battery pack is coupled with the second battery pack interface of the second power tool, the first positive voltage terminal is electrically connected to the second negative voltage terminal such that the first and second strings are electrically connected to each other in a series configuration so as to provide the second operating voltage to the second power tool,
• wherein the electrical device interface of the multi-voltage battery pack comprises a plurality of electrical terminals that are shaped and configured to physically and electrically contact corresponding electrical terminals of the first battery pack interface of the first power tool or corresponding electrical terminals of the second battery pack interface of the second power tool,
• wherein the plurality of electrical terminals of the electrical device interface comprise a first pair of batter power terminals, a signal terminal, and an additional terminal, the first pair of battery power terminals comprising a first positive power terminal electrically connected with the positive voltage terminal of the first string of battery cells and a first negative power terminal electrically connected with the negative voltage terminal of the first string of battery cells,
• wherein the first pair of battery power terminals, the signal terminal, and the additional terminal are accessible via the plurality of slots in the housing, the additional terminal and the signal terminal being vertically spaced, one above the other, and
• wherein the signal terminal is electrically connected with a thermistor in the housing, and the additional terminal is electrically coupled to a monitor circuit in the housing.

A multi-voltage battery pack for use with tools of different operating voltages, the multi-voltage battery pack comprising:

• a housing,
• a first string of battery cells arranged in electrical series and disposed inside the housing, the first string having a first positive voltage terminal and a first negative voltage terminal,
• a second string of battery cells arranged in electrical series and disposed inside the housing, the second string having a second positive voltage terminal and a second negative voltage terminal, and
• an electrical device interface shaped and configured to interchangeably (1) mechanically and electrically couple with a first battery pack interface of a first power tool that is configured to operate at a first operating voltage, and (2) mechanically and electrically couple with a second battery pack interface of a second power tool that is configured to operate at a second operating voltage,
• wherein the second operating voltage is higher than the first operating voltage,
• wherein, when the electrical device interface of the multi-voltage battery pack is coupled with the first battery pack interface of the first power tool, the first and second positive voltage terminals are electrically connected to each other and the first and second negative voltage terminals are electrically connected to each other such that the first and second strings are electrically connected to each other in a parallel configuration so as to provide the first operating voltage to the first power tool,
• wherein, when the electrical device interface of the multi-voltage battery pack is coupled with the second battery pack interface of the second power tool, the first positive voltage terminal is electrically connected to the second negative voltage terminal such that the first and second strings are electrically connected to each other in a series configuration so as to provide the second operating voltage to the second power tool, and
• wherein:
• the battery cells of the first string comprises at least five battery cells connected in series and grouped together at a first portion within the housing such that at least two cells of the first string are arranged in a first row and at least two cells of the first string are arranged in a second row below the first row;
• the battery cells of the second string comprise at least five battery cells connected in series and grouped together at a second portion within the housing which is adjacent to the first portion, wherein at least two cells of the second string are arranged in a first row and at least two cells of the second string are arranged in a second row below the first row;
• the battery cells of the first string and battery cells of the second string each define respective longitudinal axes that are parallel to each other;
• the multi-voltage battery pack has first and second opposing lateral sides;
• each of the battery cells of the first and second strings has positive and negative voltage terminals;
• the positive voltage terminals of at least two of the at least five battery cells of the first string are disposed closer to the first lateral side than the second lateral side of the battery pack;
• the positive voltage terminals of at least two of the at least five battery cells of the second string are disposed closer to the first lateral side than the second lateral side of the battery pack;
• the negative voltage terminals of at least two of the at least five battery cells of the first string are disposed closer to the first lateral side than the second lateral side of the battery pack;
• the negative voltage terminals of at least two of the at least five battery cells of the second string are disposed closer to the first lateral side than the second lateral side of the battery pack;
• the negative voltage terminals of at least two of the at least five battery cells of the first string are disposed closer to the second lateral side than the first lateral side of the battery pack;
• the negative voltage terminals of at least two of the at least five battery cells of the second string are disposed closer to the second lateral side than the first lateral side of the battery pack;
• the positive voltage terminals of at least two of the at least five battery cells of the first string are disposed closer to the second lateral side than the first lateral side of the battery pack;
• and
• the positive voltage terminals of at least two of the at least five battery cells of the second string are disposed closer to the second lateral side than the first lateral side of the battery pack.

A multi-voltage battery pack for use with tools of different operating voltages, the multi-voltage battery pack comprising:

• a housing comprising a plurality of slots therein,
• a first string of battery cells arranged in electrical series and disposed inside the housing, the first string having a first positive voltage terminal and a first negative voltage terminal,
• a second string of battery cells arranged in electrical series and disposed inside the housing, the second string having a second positive voltage terminal and a second negative voltage terminal, and
• an electrical device interface shaped and configured to interchangeably (1) mechanically and electrically couple with a first battery pack interface of a first power tool that is configured to operate at a first operating voltage, and (2) mechanically and electrically couple with a second battery pack interface of a second power tool that is configured to operate at a second operating voltage,
• wherein the second operating voltage is higher than the first operating voltage,
• wherein, when the electrical device interface of the multi-voltage battery pack is coupled with the first battery pack interface of the first power tool, the first and second positive voltage terminals are electrically connected to each other and the first and second negative voltage terminals are electrically connected to each other such that the first and second strings are electrically connected to each other in a parallel configuration so as to provide the first operating voltage to the first power tool,
• wherein, when the electrical device interface of the multi-voltage battery pack is coupled with the second battery pack interface of the second power tool, the first positive voltage terminal is electrically connected to the second negative voltage terminal such that the first and second strings are electrically connected to each other in a series configuration so as to provide the second operating voltage to the second power tool,
• wherein the electrical device interface of the multi-voltage battery pack comprises a plurality of electrical terminals that are shaped and configured to physically and electrically contact corresponding electrical terminals of the first battery pack interface of the first power tool or corresponding electrical terminals of the second battery pack interface of the second power tool,
• wherein the plurality of electrical terminals of the electrical device interface of the multi-voltage battery pack comprise a first pair of battery power terminals, a signal terminal, and an additional terminal, the first pair of battery power terminals comprising a first positive power terminal electrically connected with the positive voltage terminal of the first string of battery cells and a first negative power terminal electrically connected with the negative voltage terminal of the first string of battery cells,
• wherein the first pair of battery power terminals, the signal terminal, and the additional terminal are accessible via the plurality of slots in the housing, the additional terminal and the signal terminal being vertically spaced, one above the other,
• wherein the additional terminal is electrically coupled with a monitor circuit in the housing, and
• wherein each terminal of the first pair of battery power terminals has a greater height than each of the additional terminal and the signal terminal.