Battery pack including plural electrochemical cells encapsulated by encapsulant and method of manufacture

Abstract

Embodiments of encapsulated battery packs, control circuitry, and their methods of manufacture are described. In one such embodiment, a battery pack includes a plurality of electrochemical pouch cells and an elastomeric encapsulant that forms at least one external surface of the battery pack. In another embodiment, a battery pack includes a plurality of electrochemical pouch cells with a portion of an encapsulant disposed between the electrochemical pouch cells and the outer housing. In yet another embodiment, a method of controlling an operation of a system includes using a current threshold of one or more electrochemical cells determined at least in part on at least one of a temperature and a state of charge of the one or more electrochemical cells.

What is claimed is: 
     
         1 . A battery pack, comprising:
 a plurality of electrochemical cells;   a battery monitoring unit (BMU) in electrical communication with the electrochemical cells; and   a flash memory external to the BMU, the flash memory being configured to load updates into the flash memory with interrupting re-flashing of the BMU, thereby improving security of bootloading.   
     
     
         2 . The battery pack of  claim 1 , wherein the BMU is configured to re-flash using the updates loaded into the flash memory. 
     
     
         3 . The battery pack of  claim 1 , wherein the flash memory is a 128k byte memory device. 
     
     
         4 . The battery pack of  claim 1 , wherein the updates are firmware updates. 
     
     
         5 . A battery system, comprising:
 a battery system controller;   at least one battery pack including:
 one or more electrochemical cells; 
 one or more voltage sensors associated with the one or more electrochemical cells; and 
   at least one battery monitoring unit (BMU) including:
 a secondary overvoltage protection circuit; and 
 an interlock MOSFET in electrical communication with the secondary overvoltage protection circuit, wherein the secondary overvoltage protection circuit is configured to respond to the one or more voltage sensors sensing an overvoltage condition in the one or more electrochemical cells by causing the interlock MOSFET to change state. 
   
     
     
         6 . The battery system of  claim 5 , wherein the battery system controller is configured to determine a current threshold of the one or more electrochemical cells based at least in part on at least one of a temperature and a state of charge of the one or more electrochemical cells, and wherein the at least one controller controls an operation of the system using the current threshold. 
     
     
         7 . The battery system of  claim 6 , wherein the battery system controller determines at least two of a discharging current threshold, a regenerative charging current threshold, and a continuous charging current threshold. 
     
     
         8 . The battery system of  claim 5 , wherein the battery system controller is in electrical communication with the interlock MOSFET, the battery system controller being configured to detect the change in state of the interlock MOSFET and respond by inhibiting further charging of the at least one battery pack. 
     
     
         9 . The battery system of  claim 8 , wherein the battery system controller is configured to respond to the detected change of state of the interlock MOSFET by discharging the battery pack. 
     
     
         10 . The battery system of  claim 5 , wherein the interlock MOSFET is part of a system interlock daisy-chain. 
     
     
         11 . The battery system of  claim 5 , wherein the one or more sensors sense an overvoltage condition in the one or more electrochemical cells when a voltage of a cell exceeds a predetermined threshold voltage. 
     
     
         12 . A battery system, comprising:
 a plurality of electrochemical cells;   a battery monitoring unit (BMU) in electrical communication with the electrochemical cells, the BMU including a plurality of input ports in electrical communication with a first set of electrochemical cells of the plurality of electrochemical cells to monitor voltages of the first set of electrochemical cells and at least one auxiliary input channel in electrical communication with at least one electrochemical cell of a second set of electrochemical cells of the plurality of electrochemical cells to monitor a voltage of the at least one electrochemical cell of the second set; and   at least one secondary circuit in electrical communication with the at least one auxiliary input channel and the at least one electrochemical cell of the second set.   
     
     
         13 . The battery system of  claim 12 ; wherein the at least one secondary circuit includes an N-Channel MOSFET to inhibit current leakage during a sleep mode of the BMU. 
     
     
         14 . The battery system of  claim 12 , wherein the at least one secondary circuit includes a voltage divider circuit to reduce a sensed voltage of the at least one electrochemical cell of the second set for input to the at least one auxiliary input channel. 
     
     
         15 . The battery system of  claim 12 , wherein the second set of electrochemical cells includes a plurality of electrochemical cells. 
     
     
         16 . A battery system, comprising:
 a plurality of electrochemical cells;   a battery monitoring unit (BMU) in electrical communication with the electrochemical cells; and   a standby power supply switch-over circuit in electrical communication with the battery monitoring unit, the switch-over circuit including a normally closed relay configured to respond to standby signal from the BMU by sourcing a voltage to bias a standby circuit of the BMU and to respond to an active signal from the BMU by opening to remove the voltage from the standby circuit.   
     
     
         17 . The battery system of  claim 16 , wherein the switch-over circuit further includes an opto diode in electrical communication with the BMU, and wherein a current flow through the opto diode in response to the active signal causes the normally closed relay to open. 
     
     
         18 . The battery system of  claim 16 , wherein the standby signal is a first voltage and the active signal is a second voltage that is greater than the first voltage. 
     
     
         19 . The battery system of  claim 16 , wherein the standby signal indicates that the BMU is operating in a sleep mode and the active signal indicates that the BMU is operating in an active mode.