12V to 24V DC-DC Chargers

12V to 24V DC-DC Battery Chargers for Mixed-Voltage Systems

A 12V to 24V DC-DC charger lets a 12V alternator or start battery charge a 24V house or auxiliary battery bank. The charger steps up the voltage and applies a controlled, multi-stage charge profile. It suits systems where the vehicle or engine runs on 12V but the auxiliary system was built at 24V, for example to reduce current draw for an inverter or other high-load equipment. This range includes the Victron Orion-Tr Smart and Orion XS 1400 series, plus the Enerdrive ePower DC-DC/MPPT charger with combined solar input.

Choosing the Right 12V to 24V DC-DC Charger

Start with the charge current you need. Then decide whether the circuit should be isolated, and whether you want solar charging built into the same unit. The models here cover these options:

• Victron Orion-Tr Smart 12/24-10A Isolated: a compact choice for smaller 24V banks. Galvanic isolation separates the input and output circuits.
• Victron Orion-Tr Smart 12/24-15A Isolated: higher charge current with full isolation. It suits marine and installations sensitive to electrical noise.
• Victron Orion-Tr Smart 12/24-15A Non-isolated: the same 15A output with a shared negative. This is a practical option where isolation is not required.
• Victron Orion XS 1400 DC-DC Smart Battery Charger: a high-output, high-efficiency charger for larger battery banks and faster recharge between stops.
• Enerdrive 24V 30A ePower DC-DC/MPPT Charger: combines DC-DC charging with an MPPT solar regulator, so one unit handles both alternator and solar input.

If you are unsure whether your installation needs galvanic isolation, our guide to isolated vs non-isolated DC-DC chargers and converters explains the differences in grounding, safety and noise.

Why Use a Dedicated DC-DC Charger?

Connecting a 12V alternator straight to a 24V bank is not possible. Simple voltage converters also lack proper charge control. A dedicated DC-DC battery charger supplies a stable output voltage and selectable charge profiles for lithium (LiFePO4), AGM and other chemistries. It also protects both batteries from over-discharge or overcharge. The Victron Smart models offer Bluetooth monitoring and setup through the VictronConnect app, which makes configuration and fault finding easier.

Common Use Cases

Caravan and RV: charge a 24V lithium house bank from a 12V tow vehicle while driving, so a 24V inverter can run higher loads more efficiently.

Marine and boats: keep a 24V house bank charged from a 12V engine alternator. Isolated models are a sound choice for onboard systems.

4WD and camper trailers: top up a 24V auxiliary bank on long touring days. Use the Enerdrive ePower to add roof or portable solar through the same charger.

Off-grid, tiny home and commercial vehicles: charge 24V equipment banks from a 12V service vehicle for tools, lighting and refrigeration.

Need a different voltage combination? Browse the full 24V DC-DC chargers range, or see 24V to 24V DC-DC chargers for vehicles with a 24V start system. Compare the models above by current, isolation and solar capability, then choose the 12V to 24V DC-DC charger that suits your build and keep your 24V bank charged on every trip.