12V to 28V 50A Step-Up Converter | Caravan Charging Booster

Get more from your existing caravan charging cable.

Struggling to charge your caravan batteries while driving? Long cable runs and excessive voltage drop can leave your DC-DC charger without the supply it needs to charge effectively.

The Falcon 12V to 28V Step-Up Converter raises the supply voltage before it travels from your tow vehicle to your caravan. Your compatible DC-DC charger then converts that supply into the correct charging voltage for your battery.

Higher voltage means less current through the long cable run. For the same power, a 28V supply carries approximately half the current of a 14V supply, reducing voltage drop and heat lost in the wiring. Actual results depend on the installation and conversion losses.

In suitable installations, this can allow you to retain existing 8 AWG charging cable rather than replace the entire cable run, saving on materials and labour. Cable length, condition, connections and current capacity must still be checked—not every existing installation will be suitable.

Designed for use with compatible 12V DC-DC battery chargers up to 40A output. This converter supplies your charger; it does not replace it.

Specifications

The converter’s 50A output rating is not the battery charging current. The maximum charger size for this application is 40A.

Compatibility and Installation

• Check the exact charger model. A “24V compatible” label or a high solar-input rating alone is not sufficient. The charger’s vehicle input must accept the converter’s output. REDARC BCDC1225D and BCDC1240D models specify a 9–32V input range, but complete system compatibility still needs checking.
• Install at the vehicle end, after suitable supply isolation and before the long cable run. For the proposed VSR installation, this means the load side of the voltage-sensitive relay. The 12V input wiring, relay and protection must handle the higher input current; only the boosted cable run benefits from the lower current.
• Smart-alternator vehicles require additional checks. A conventional VSR may disconnect when alternator voltage falls. This converter cannot maintain charging after its supply has been disconnected; the vehicle may require a different, suitably controlled isolation arrangement.

Important: The boosted feed must be dedicated to compatible equipment. Do not connect the 28V output directly to a 12V battery, fridge or other 12V-only accessories. Existing shared Anderson-plug circuits must be checked before conversion.

Installation and cable suitability should be assessed by a qualified auto electrician.