- Automatically combines two batteries during charging and isolates them when not in use, ensuring optimal battery maintenance. - The Automatic 12V 140Amp Double Battery Isolator is essential for charging two battery sets. Its voltage-sensitive relays activate at 13.3 volts and deactivate at 12.8 volts, guaranteeing that your primary battery remains charged and ready to start your vehicle. - Featuring an imported power management chip, this power isolator utilizes advanced electronic circuit technology for intelligent automatic management. It is designed to be strong, waterproof, energy-efficient, and provides excellent heat dissipation with low power loss. - Ideal for DC12V two battery sets, this isolator is universally compatible with cars, vehicles, boats, and other dual battery electrical systems. - Use scenarios: 1. Perfect for recreational vehicles (RVs) that require reliable power management for both starting and auxiliary batteries. 2. Suitable for marine applications, ensuring that your boat's starting battery is always charged while powering additional electronics. 3. Great for off-road vehicles, providing peace of mind that your primary battery will be ready for ignition, even when using auxiliary power.