MasterVolt Battery Isolators & Voltage Sensitive Relays
MasterVolt Battery Isolators & Voltage Sensitive Relays: Precision Charging for Multi-Bank Systems
When an onboard electrical system demands that two or more battery banks charge simultaneously — and remain isolated during discharge — the quality of the isolator at the heart of that system matters enormously. MasterVolt has built its reputation as a specialist in the management, conversion, and storage of electrical energy, and its approach to battery isolators and voltage sensitive relays reflects that same engineering discipline found throughout its broader power portfolio.
Two Distinct Technologies, One Goal
MasterVolt offers two complementary families of battery isolators, each suited to different system requirements. The BI series relies on conventional diode technology. These units are fully solid-state, meaning there are no moving parts to wear out over time. The housings are constructed from completely corrosion-proof materials with aluminium heat sinks, and the electronic components are encased in synthetic materials for long-term durability — an important trait in the demanding marine and mobile environments where MasterVolt products are commonly deployed.
The diode-based design does introduce a small voltage drop (approximately 0.6 V), but this is easily compensated for when paired with compatible MasterVolt charging equipment: the Mass battery chargers and Alpha Pro charge regulators include automatic voltage drop compensation as a standard feature, making the BI series a natural fit within an integrated MasterVolt system.
For installers who need to eliminate voltage drop entirely — or who are working with alternators whose output voltage cannot be adjusted — MasterVolt's Battery Mate series takes a more sophisticated approach. Rather than diodes, the Battery Mate uses MOSFET transistor technology. Its components actively compensate for voltage variations and ensure charging continues at the correct voltage level even across several battery banks simultaneously. The Battery Mate is compatible with any type of alternator or battery charger, whether in a new build or a retrofit installation.
Flexible Capacity for a Range of Applications
The Battery Mate lineup scales to match the demands of the application. Models 1602 and 1603 are designed for alternators with a maximum charge current of 160 A, while the Battery Mate 2503 handles alternators up to 250 A. An LED display on each unit indicates whether power input is active, providing at-a-glance confidence during operation. Installation is straightforward thanks to DIN rail mounting compatibility, corrosion-proof housings, aluminium heat sinks, and solid bolt connections with nuts and locking rings.
Built for Marine and Mobile Demands
MasterVolt has been an innovation-driven company since its founding in 1991, with product development carried out across three R&D centers. Its electrical solutions are used across demanding markets including marine, mobile, offshore, and industrial applications. The battery isolator range reflects this pedigree: whether you are protecting an engine start battery from being depleted by house loads, or managing a complex multi-bank setup aboard a cruising yacht, MasterVolt engineering provides the reliability these environments require.
Explore the full MasterVolt brand catalog or browse all battery isolators and voltage sensitive relays to find the right solution for your system.