Method and system for battery protection

An electrical combination comprising:

• a battery pack configured to supply power to a cordless power tool having a motor, the battery pack including a plurality of battery cells operable to supply a battery pack discharge current to the motor of the cordless power tool, each of the battery cells being individually tapped and having a battery cell state of charge, the battery pack including a terminal configured to provide a communication path between the battery pack and the cordless power tool;
• a switch operable to be alternately positioned in one of a conducting state and a non-conducting state, the switch further operable to enable the supply of discharge current from the battery pack to the motor when the switch is positioned in the conducting state and operable to interrupt the supply of discharge current from the battery pack to the motor when the switch is positioned in the non-conducting state;
• and
• a controller electrically connected to the switch, operable to monitor the respective battery cell state of charge of each of the battery cells, operable to control operation of the battery pack, and operable to control the positioning of the switch, the controller including a microcontroller;
• wherein the controller modifies operation of the battery pack by causing the switch to move from the conducting state to the non-conducting state to interrupt the supply of discharge current from the battery pack to the motor when the monitored respective battery cell state of charge of one of the battery cells reaches a predetermined threshold.