Balmar Centerfielder II

Synchronised Twin-Engine Alternator Charging for 12V and 24V Marine Systems

Managing power on a vessel with twin propulsion engines often presents a significant electrical challenge: getting two separate charging systems to work together efficiently. The Balmar Centerfielder II (CFII-12/24) is an intelligent charge-balancing module engineered to unify port and starboard alternators, allowing you to safely and rapidly charge a single large house battery bank using the combined output of both engines.

Designed specifically for multihulls, catamarans, and twin-engine powerboats, this system acts as a central coordinator. By constantly monitoring the port and starboard external voltage regulators, the Centerfielder II automatically designates the starboard regulator as the dominant controller when both engines are running. This seamless integration ensures both alternators work in harmony rather than competing against one another.

Eliminate Regulator Conflict and the "Yo-Yo" Effect

When two independent voltage regulators attempt to charge the same battery bank simultaneously, slight variations in voltage sensing often cause one regulator to shut down prematurely while the other takes the full load. As the battery approaches its target voltage, the two systems can repeatedly cycle on and off in conflict. This phenomenon, known as the "yo-yo effect" or alternator chatter, leads to inefficient charging.

The Centerfielder II resolves this issue by unifying the field current when both systems are active. If you choose to shut down one engine while cruising or motor-sailing, the unit automatically isolates the regulators and alternators, allowing the single running engine to manage the charging profile independently without manual intervention.

Key Features and System Capabilities

• Balances Twin-Engine Charging: Combines the output of port and starboard alternators to efficiently charge a single, high-capacity house battery bank.
• Eliminates Alternator Chatter: Unifies field current control to prevent regulators from cycling on and off as batteries near full charge.
• Dual Voltage Compatibility: Fully compatible with both 12V and 24V marine electrical architectures.
• Automatic Single-Engine Isolation: Seamlessly reverts to independent regulator operation when only one propulsion engine is running.
• Complete Installation Kit: Includes upgraded regulator power wires and inline fusing for reliable circuit protection.
• Expandable Charging Options: Can be used with the Balmar Digital Duo Charge to charge a second battery.

Important Compatibility Requirements

The Centerfielder II is designed exclusively for Balmar Max Charge voltage regulators: the MC-614 and MC-618 (12V) and the MC-624 (24V). It cannot be used with internally regulated alternators or the Balmar ARS-5 regulator.

Engineered for Demanding Marine Applications

Relying on uncoordinated charging systems risks undercharged house banks and overstressed engine room components. By installing a dedicated balancing controller, vessel owners can maximise their alternator investment, reduce engine run times, and maintain healthier battery banks over long voyages.

Documents

• Balmar Centerfielder II Installation and Operation Manual (PDF)

Upgrade Your Vessel's Charging Efficiency

Equip your twin-engine catamaran or powerboat with the Balmar Centerfielder II to achieve balanced, reliable alternator performance on the water.