12V to 48V DC-DC Chargers

Charge a 48V Battery Bank from a 12V Source

A 12V to 48V DC-DC charger lets a 12V supply, such as a vehicle starter battery, alternator circuit or 12V house bank, deliver charge into a 48V battery system. This collection features the Victron Orion-Tr 12/48-8A Isolated DC-DC Charger. It is built for mixed-voltage installations where a higher-voltage 48V bank runs inverters and heavy loads while the base vehicle or vessel stays on 12V.

Rather than running a separate charging source for the 48V bank, a 12/48 charger converts the lower supply voltage up to a regulated 48V charging output. This gives you a controlled way to top up the high-voltage bank while driving or while a 12V source is available.

Why Choose an Isolated 12/48 DC-DC Charger

The Orion-Tr 12/48-8A is an isolated unit. The input and output sides are galvanically separated, so the 12V and 48V systems do not share a common negative path. In installations with multiple voltages, this separation helps reduce ground loop issues and keeps the 12V chassis electrical system independent from the 48V bank. For a detailed explanation of when isolation matters, see our guide to isolated vs non-isolated DC-DC chargers and converters.

Key points to consider when selecting a 12V to 48V charger:

• Charge current: The 8A output rating suits supplementary or maintenance charging of a 48V bank, rather than replacing a primary solar or mains charging source.
• Input supply capacity: Stepping up from 12V draws considerably more current on the input side than the charger delivers on the output. Size cabling and fusing to suit.
• Isolation: Isolated operation keeps the 12V and 48V circuits electrically separate. This is often preferred in vehicles, vessels and mixed-voltage systems.
• Battery compatibility: Confirm the charger's output settings suit your 48V battery chemistry before commissioning.
• Proven range: The Victron Orion-Tr series is widely used in mobile and off-grid power systems.

Related 48V Charging Options

If your supply is 24V rather than 12V, browse our 24V to 48V DC-DC chargers. To compare every input voltage option side by side, view the full 48V DC-DC chargers range.

Common Use Cases

• Caravan and RV: Charging a 48V lithium house bank from the tow vehicle's or motorhome's 12V system while travelling.
• 4WD and truck builds: Feeding a 48V auxiliary bank that powers larger inverters, while the vehicle electrics remain on 12V.
• Marine and boats: Linking a 12V engine start system to a 48V house or propulsion bank, with isolation between circuits.
• Off-grid and tiny home: Using an existing 12V source to support a 48V storage system.
• Commercial and industrial: Service vehicles and mobile equipment that combine 12V vehicle electrics with 48V tool or equipment power.

If you are adding a 48V bank to a 12V vehicle or vessel, the Victron Orion-Tr 12/48-8A gives you a dependable, isolated link between the two systems. Order yours today and keep your 48V battery charged from the 12V power you already have.