Hellroaring Technologies’ BIC-75150A battery isolator/combiner (BIC) is designed to protect sensitive police electronics from low-voltage dropouts during engine starts and to protect the start battery from being drained by auxiliary battery electronics such as radios and video equipment. Constructed with solid state components and completely sealed, the BIC-75150A installs with a single positive wire from the alternator to the auxiliary battery. The BIC is waterproof and not susceptible to the vibration that police cars generally encounter.