Our new state-of-the-art, fully automatic dual battery controller is suitable for any vehicle with an auxiliary battery. Smaller and lighter than other standard battery isolators, the Battery Doctor® 100 and 150 Ampere Battery Isolator employs electronic switching control technology. Our high-performance electronic isolator allows you to charge two batteries from a single alternator, and keeps the starting battery isolated from the second battery. Also, with a single push of the override/reset button, you can change the batteries to parallel mode for jump starting.