12V to 12V DC-DC Chargers

12V to 12V DC-DC Battery Chargers for Auxiliary Power

A 12V to 12V DC-DC charger takes power from your vehicle's alternator and start battery and delivers a controlled, multi-stage charge to a separate auxiliary or house battery. It does this while you drive. Compared with a simple isolator, a dedicated battery-to-battery charger lets you match the charge profile to your auxiliary battery chemistry, including lithium (LiFePO4), AGM and flooded lead-acid. This helps your house bank reach a proper state of charge rather than sitting partly charged.

This range covers Victron Orion-Tr Smart and Orion XS models, plus Enerdrive DC-DC/MPPT chargers. Output options run from compact 18A units to high-current 100A chargers for larger battery banks. For 24V and 48V input options, see the full 12V DC-DC chargers range.

How to Choose the Right 12V DC-DC Charger

Start with your battery bank capacity, alternator output and cable run. Then compare the key differences across the range:

• Isolated or non-isolated: The Victron Orion-Tr Smart 12/12-18A and 12/12-30A are available in isolated versions, which galvanically separate the input and output circuits. The 12/12-30A is also offered as a non-isolated model for common-negative installations. Our guide to isolated vs non-isolated DC-DC chargers explains when each type suits your setup.
• Charge current: Choose 18A or 30A for smaller auxiliary batteries. The Victron Orion XS 12/12-50A (EMC improved version) and 70A Orion XS suit larger lithium banks. The Enerdrive 100A DC-DC/MPPT charger is designed for high-capacity systems.
• Combined solar input: The Enerdrive 40A+ ePower and Enerdrive 100A units combine DC-DC and MPPT charging. This means alternator and solar input can be managed by one device.
• 12V and 24V flexibility: The Victron Orion XS 1400 DC-DC Smart Battery Charger suits both 12V and 24V systems. It is a versatile choice for mixed-voltage builds.
• Smart monitoring: The Victron Orion-Tr Smart and Orion XS models allow configuration and monitoring through the VictronConnect app.

Correct cable sizing and fusing are just as important as charger selection. Higher-current models need appropriately rated cabling between the start battery and the charger.

Common Use Cases

Caravans and RVs: Keep a lithium or AGM house battery charged on travel days so fridges, lighting and water pumps are ready when you arrive.

4WD and touring vehicles: Charge a dual battery system in the canopy or tub while driving between remote camps.

Marine and boats: Charge house batteries from the engine alternator while protecting the start battery.

Trucks and commercial vehicles: Power auxiliary equipment on 12V fleets, or step down from a 24V chassis with our 24V to 12V DC-DC chargers.

Off-grid and tiny homes: The Enerdrive DC-DC/MPPT models can also manage solar input for mobile or semi-permanent setups.

Charge Smarter on Every Trip

Whether you need a compact Victron Orion-Tr Smart charger for a single auxiliary battery or a high-output Orion XS or Enerdrive unit for a large lithium bank, there is a 12V DC-DC charger here to suit your build. Compare the models above and choose the output and features that match your system. Your house batteries will then arrive at camp charged and ready.