Additiona l Bat tery T empera ture Sensor s (Part # : 808-0232-01) can be install ed on your XC Seri es or BC S eries ba ttery char ger . Xa ntrex r ecommends that you inst all Batte ry T emperatur e Sensors on all banks to prot ect your batterie s an d to provide optim al cha rging of each ban k. See the la bel on the o utsi de o f t he p a ckag e ...