High power battery-powered system

Abstract

An electrical combination, a motorized device system, a motor assembly, a battery pack, and operating methods. The combination may include an electrical device including a device housing, a load supported by the device housing, the load being operable to output at least about 1800 watts (W), and a device terminal electrically connected to the load; a battery pack including a pack housing, battery cells supported by the pack housing, the battery cells being electrically connected and having a nominal voltage of up to about 20 volts, and a pack terminal electrically connectable to the device terminal to transfer current between the battery pack and the electrical device; and a controller operable to control the transfer of current.

What is claimed is: 
     
         1 . A battery pack comprising:
 a housing;   a plurality of cells supported by the housing and having a voltage;   a battery terminal;   an electrical circuit selectively connecting the plurality of cells to the battery terminal to supply a current to an electrical device, the circuit including a resistor in a first electrical path between the plurality of cells and the battery terminal, the resistor having a first resistance, and a switch in a second electrical path between the plurality of cells and the battery terminal, the switch having a second resistance less than the first resistance; and   a controller operable to selectively connect the plurality of cells to the battery terminal across the resistor or through the switch.   
     
     
         2 . The battery pack of  claim 1 , wherein the controller is operable to control the switch to short the resistor. 
     
     
         3 . The battery pack of  claim 2 , wherein the controller is operable to close the switch to short the resistor. 
     
     
         4 . The battery pack of  claim 2 , wherein the controller is operable to control the switch after a condition occurs. 
     
     
         5 . The battery pack of  claim 4 , wherein the controller is operable to control the switch after a time period has elapsed. 
     
     
         6 . The battery pack of  claim 5 , wherein the controller is operable to control the switch after a time period after start-up. 
     
     
         7 . The battery pack of  claim 1 , wherein the switch includes a field effect transistor (FET). 
     
     
         8 . An electrical combination comprising:
 an electrical device including a device housing, a load supported by the device housing, and a device terminal electrically connected to the load;   a battery pack including a pack housing, battery cells supported by the pack housing, the battery cells being electrically connected, and a pack terminal electrically connectable to the device terminal to transfer current between the battery pack and the electrical device; and   an electrical circuit between the battery cells and the load and including
 a discharge switch operable to selectively connect the battery cells to the load, 
 an operation switch operable to output an operation signal, 
 a controller operable to determine a condition of the electrical device or the battery pack, and 
 a logic portion operable to receive a first input from the operation switch and a second input from the controller, the logic portion outputting a control signal to the discharge switch based on the first input and the second input. 
   
     
     
         9 . The combination of  claim 8 , wherein the discharge switch includes an electromechanical relay or a semiconductor based solid state relay. 
     
     
         10 . A battery pack comprising:
 a housing including a support portion connectable to and supportable by an electrical device, the support portion defining a channel operable to receive a projection on the electrical device, the support portion including a plastic material molded to define the channel, and a metal material molded in the plastic material, the metal material defining a C-shaped portion around the channel;   a plurality of battery cells supported by the housing; and   a battery terminal electrically connected to the plurality of battery cells and connectable to a terminal of the electrical device.   
     
     
         11 . The battery pack of  claim 10 , wherein the metal material includes a metal stamping. 
     
     
         12 . The battery pack of  claim 10 , wherein the support portion defines a first channel operable to receive a first projection on the electrical device and a second channel operable to receive a second projection on the electrical device, the plastic material being molded to define the first channel and the second channel, the metal material defining a first C-shaped portion around the first channel and a second C-shaped portion around the second channel. 
     
     
         13 . The battery pack of  claim 12 , wherein the metal material includes a connecting member connected between the first C-shaped portion and the second C-shaped portion. 
     
     
         14 . The battery pack of  claim 13 , further comprising a terminal block including the battery terminal, the battery terminal being engageable from one end of the housing, the first C-shaped portion and the second C-shaped portion being on opposite sides of the terminal block, at least a portion of the connecting member being between the terminal block and the one end. 
     
     
         15 . The battery pack of  claim 14 , wherein the housing has a surface between the terminal block and the one end, the connecting member supporting the surface.