Blue Sea Systems Add-A-Battery Kit 7650 — 120A Dual Circuit System for Boats

Upgrade how power is managed on your boat with the Blue Sea Systems 7650 Add-A-Battery Kit. Built for vessels with two battery banks, this system combines smart control with rugged hardware to streamline charging, switching, and starting power without the need for external regulators or isolators. The kit centers on an automatic charging relay and a Dual Circuit Plus switch, delivering a cohesive solution for both the starter and house banks.

How it works is straightforward and practical. An automatic charging relay senses when charging voltage is present and connects the banks during engine operation. When charging ends and voltage falls, the system isolates the banks to protect sensitive electronics and help preserve starting power for the moment you need it most. If one bank becomes discharged, an emergency parallel feature allows both batteries to be linked for engine starting, providing a safety net that can be especially valuable on longer trips or in remote locations.

Designed to endure marine conditions, the system uses corrosion resistant tin plated copper studs for reliable conductivity and long service life. With a continuous rating of 120 A, it supports inboards and larger outboards, giving you robust power distribution across your boat’s electrical systems. The result is a streamlined setup where two banks are controlled with a single ON and OFF operation, reducing switching errors and wiring complexity while maintaining essential reserve capacity for critical systems.

Real-world use cases illustrate the versatility of this kit. Weekend anglers can appreciate the simplified control that minimizes cockpit clutter, while coastal cruisers may value automatic charge sharing that helps keep two banks in balance during multi-day trips. The combination of automatic charging, independent bank control, and an emergency link creates a flexible power core that adapts to shifting boat loads and operating conditions without requiring constant manual adjustments.

Core capabilities include a sense-and-link automatic charging relay, a dual circuit plus switch for starter and house banks, an emergency parallel function for engine starting, a single on-off interface for both banks, and marine-rated components designed to resist corrosion in harsh environments. Collectively, these features aim to deliver dependable power management while keeping installation straightforward and maintenance low.

• AUTOMATIC CHARGING RELAY that senses charge voltage and links banks during charging while isolating at rest
• DUAL CIRCUIT PLUS SWITCH that manages starter and house banks independently and protects reserve capacity
• EMERGENCY PARALLEL FUNCTION that can link batteries to enable engine starting if one bank is discharged
• SIMPLE TWO BANK CONTROL with a single ON and OFF operation for everyday use
• MARINE RATED COMPONENTS featuring tin plated copper studs for corrosion resistance and durability

In sum, the Blue Sea Systems 7650 adds a practical, automated power management layer that can simplify wiring, keep critical systems powered, and adapt to sailing or boating routines without overpromising results. Consider it a flexible upgrade option for boaters seeking cleaner power distribution and easier battery management on board.