Battery pack
An electrical combination. The electrical combination comprises a battery pack configured to be interfaced with a hand held power tool, a control component, and a semiconducting switch. The transfer of power from the battery pack to the hand held power tool is controlled by the control component and the switch based on one of a battery pack state of charge and a respective state of charge of one of a plurality of battery cells. A discharge current of the battery pack is regulated based on the switch being controlled into one of a first state and a second state by the control component to selectively enable the transfer power from the plurality of battery cells to the hand held power tool.
1. An electrical combination comprising:
a battery pack configured to be interfaced with a hand held power tool, the battery pack including
a battery pack housing connectable to and supportable by the hand held power tool,
a plurality of terminals configured to be interfaced with corresponding terminals of the hand held power tool, and
a plurality of battery cells arranged within and supported by the housing, each of the plurality of battery cells being rechargeable and having a lithium-based chemistry, each of the plurality of battery cells having a respective state of charge, the battery pack having a battery pack state of charge, power being transferable from the plurality of battery cells to the hand held power tool when the battery pack is connected to the hand held power tool;
a control component; and
a semiconducting switch electrically connected to at least one of the plurality of terminals;
wherein the transfer of power from the battery pack to the hand held power tool is controlled by the control component and the switch based on one of the battery pack state of charge and the respective state of charge of one of the plurality of battery cells; and
wherein a discharge current of the battery pack is regulated based on the switch being controlled into one of a first state and a second state by the control component to selectively enable the transfer of power from the plurality of battery cells to the hand held power tool.
2. The combination of claim 1 , wherein the control component includes a microprocessor.
3. The combination of claim 2 , wherein the microprocessor is within the battery pack housing.
4. The combination of claim 1 , wherein the switch includes a field-effect transistor (“FET”).
5. The combination of claim 4 , wherein the FET is within the battery pack housing.
6. The combination of claim 1 , wherein the control component and the switch are within the battery pack housing.
7. The combination of claim 1 , further comprising a heat sink in a heat transfer relationship with the switch.
8. The combination of claim 1 , wherein the first state of the switch interrupts a discharge current from the plurality of battery cells to the hand held power tool.
9. The combination of claim 1 , further comprising the hand held power tool.
10. The combination of claim 9 , wherein the control component includes a microprocessor.
11. The combination of claim 10 , wherein the hand held power tool includes a power tool housing, and wherein the microprocessor is within the power tool housing.
12. The combination of claim 9 , wherein the switch includes a field-effect transistor (“FET”).
13. The combination of claim 12 , wherein the hand held power tool includes a power tool housing, and wherein the FET is within the power tool housing.
14. The combination of claim 9 , wherein the hand held power tool includes a power tool housing, and wherein the control component and the switch are within the power tool housing.
15. The combination of claim 9 , wherein the hand held power tool includes one of a circular saw and a driver drill.
16. The combination of claim 1 , wherein the lithium-based chemistry includes manganese.
17. The combination of claim 1 , further comprising a locking assembly operable to lock the battery pack to the hand held power tool, the locking assembly including an actuator.
18. The combination of claim 1 , wherein the plurality of battery cells are electrically connected in a partial parallel and partial series arrangement.
19. The combination of claim 1 , wherein the battery pack state of charge is a voltage.
20. The combination of claim 1 , wherein the respective state of charge of one of the plurality of battery cells is a voltage.
21. The combination of claim 1 , wherein the control component is operable to prevent the battery pack from entering an over-discharged state based on a predetermined threshold for one of the battery pack state of charge and the respective state of charge of one of the plurality of battery cells.
22. The combination of claim 21 , wherein the battery pack state of charge is a voltage.
23. The combination of claim 21 , wherein the respective state of charge of one of the plurality of battery cells is a voltage.
24. The combination of claim 1 , further comprising a fuel gauge including a plurality of light-emitting diodes, the fuel gauge being operable to display a representation of the battery pack state of charge.