12V 140 Amp Dual Battery Smart Isolator by KeyLine - VSR - Voltage Sensitive Relay Specially Designed for ATV, UTV, Boats, RV's, Campers 5th Wheels Off Road Vehicles Rhino Polaris Artic Cat ETC ZERO VOLTAGE DROP: Forget the traditional diode relays and so-called "solid state" devices that can rob you of almost 2 amps of output voltage! The Keyline Dual Battery Isolator is the only unit designed with cutting edge programming to deliver optimum performance - with ZERO sacrifice. This compact battery isolator was built ultra-small (2.6" x 2.6" x 2") to fit almost anywhere! A perfect fit under the hood to get close to your dual batteries. VOLTAGE SENSITIVE RELAY: The KeyLine Automatic 140 Amp Dual Battery Isolator is all you need to charge Two Battery Systems. Voltage Sensitive Relay (VSR) cuts in at 13.3 volts and cuts out at 12.8 volts to ensure your primary battery is always charged and ready to start your vehicle. It's like having two separate power sources for each battery while only having one alternator! CERTIFIED SAFE: Unlike other isolators on the market, the KeyLine Automatic 140 Amp Dual Battery Isolator is IP65 Certified. This International Protection rating means that your KeyLine charger is safe for use even for your off-road needs in dusty, wet and unexpected extreme weather environments. Great for extreme vibration applications as well. EASY-TO-USE: The 140 Amp Dual Battery Smart Isolator comes with mounting plate and hardware. Does not include installation wires. Easy-to-follow directions for the most novice DIYer. What could be easier? **If you need installation wiring, see Dual Battery Kit or ATV/UTV Kit. BUY WITH CONFIDENCE: Every 140 Amp Dual Battery Isolator is backed by an industry leading 12-month warranty. If you are not 100% satisfied with your purchase, simply take advantage of the No Questions Asked, 30-Day Money Back Guarantee!!