Mastervolt BI703 BI Series Battery Isolator 70 Amp 3 Battery

Meet the Mastervolt BI703 BI Series Battery Isolator—the smart way to split charge current across multiple batteries with minimal energy loss. This 70 Amp isolator is designed for 3-battery configurations, ensuring reliable, independent charging for 12V or 24V systems.

• Three independent charging paths: 3 outlets provide separate charging for up to three batteries, helping keep banks balanced on 12V or 24V systems.
• High current capability: Max output from a charger 50 A; max output from the alternator 70 A for robust charging performance.
• 12V or 24V system compatibility: Designed for 12V or 24V configurations, with separate charging for each battery.
• Charge Mate: Connects and/or disconnects two batteries for simple configuration control.
• Battery Watch: Monitors battery condition and can function as a main switch when needed.
• Durable, marine-grade construction: Solid-state, corrosion-proof materials and aluminum heat sinks, built to withstand marine and on-board environments with no moving parts to wear.
• Easy installation: Molded diode splitters, end plates with connection lugs, and solid bolt connections with nuts and locking rings.
• Compact size: 8.1 x 5.5 x 3.1 in; weight approx. 2.4 lb (1.1 kg).
• Voltage drop considerations: Diode voltage drop (~0.6 V) can be compensated by adjusting charger or alternator output, or by using Mastervolt Mass chargers or Alpha Pro regulators with automatic voltage drop compensation. Compensation diode: No built-in.

The BI703 ensures efficient, balanced charging for a multi-battery setup, reducing energy waste and extending battery life. With three independent charging paths, banks stay balanced, while Charge Mate and Battery Watch offer simple control and ongoing monitoring. The solid-state, marine-grade construction withstands harsh on-board environments with no moving parts to wear, and the compact footprint makes installation straightforward. For higher-power charging, it supports up to 50 A from a charger and 70 A from the alternator, with practical voltage drop compensation available via compatible Mastervolt or Alpha Pro equipment.