Redundant battery protection system and method

Abstract

An enhanced battery pack having an enhanced protection system addresses a potential weakness of the conventional protection system of a conventional battery pack. The enhanced protection system includes both the convention protection circuit and a redundant protection circuit. The redundant protection circuit is either a duplicate copy of the conventional protection circuit or is at least a functional equivalent of the conventional protection circuit. The components of the redundant protection circuit are electrically coupled into the enhanced battery pack in a parallel fashion with the corresponding components of the conventional protection circuit. Consequently, if one or more components of the conventional protection circuit fail due to defective conditions of the one or more components of the conventional protection circuit, the redundant protection circuit will still be operable to allow the enhanced battery pack to function while the enhanced protection system continues to protect the enhanced battery pack.

1 . A battery pack comprising:
 a first external terminal;   a second external terminal;   a first battery cell electrically coupled with the first external terminal and the second external terminal;   a first electrical switch electrically coupled in series with the first battery cell and the first external terminal;   a first protection circuit electrically coupled to the first battery cell and electrically coupled to the first electrical switch, the first protection circuit having a first state when a first electrical condition of the first battery cell exists and having an absence of the first state when the first condition does not exist, the first electrical switch configured to be in an electrically open circuit state to prevent electrical current from flowing through the first electrical switch when the first state of the first protection circuit exists and to be in an electrically closed circuit state to allow electrical current to flow through the first electrical switch when the first state of the first protection circuit is absent;   a second electrical switch electrically coupled in series with the first battery cell and the first external terminal, the second electrical switch electrically coupled in parallel with the first electrical switch; and   a second protection circuit electrically coupled to the first battery cell and electrically coupled to the second electrical switch, the second protection circuit having a first state when the first electrical condition of the first battery cell exists and having an absence of the first state when the first condition does not exist, the second electrical switch configured to be in an electrically open circuit state to prevent electrical current from flowing through the second electrical switch when the first state of the second protection circuit exists and to be in an electrically closed circuit state to allow electrical current to flow through the second electrical switch when the first state of the second protection circuit is absent.   
   
   
       2 - 16 . (canceled)