DC-DC Charging

DC-DC Battery Chargers: High-Efficiency Charging While You Drive.

Ensure your house batteries are fully charged and ready for adventure by the time you reach your destination. A DC-DC Battery Charger is an essential component for any modern New Zealand caravan or motorhome, acting as a smart bridge between your vehicle's alternator and your secondary battery bank. Unlike traditional solenoid systems, a DC-DC charger provides a tailored, multi-stage charge that ensures your deep cycle batteries—whether AGM, Gel, or Lithium—are topped up to 100% every time you hit the road.

At RV World, we stock the industry's most reliable brands, including Redarc, Enerdrive, CTEK, and BM Pro, with charging outputs ranging from 12A to a massive 120A.

Overcoming Smart Alternators & Voltage Drop

Modern Euro-5 and Euro-6 vehicles are equipped with "Smart Alternators" designed to reduce fuel consumption by lowering voltage once the starting battery is full. This often results in your house batteries receiving little to no charge. A DC-DC charger solves this by boosting the voltage to the correct levels required for deep cycle chemistry. Additionally, it overcomes the issue of voltage drop caused by long cable runs between your vehicle's engine bay and the caravan battery, ensuring consistent power delivery regardless of the distance.

Integrated Solar & Advanced Battery Management

Many of our premium DC-DC units, such as the Redarc BCDC "D" Range and Enerdrive ePower, feature an integrated MPPT Solar Regulator. This allowing you to connect solar panels directly to the charger, which then intelligently prioritises charging from the alternator while driving and switches to solar once you are parked. For those seeking a complete "all-in-one" solution, we also offer advanced Battery Management Systems (BMS) like the Redarc Manager30, which combines AC charging, DC-DC charging, and solar regulation into a single sophisticated unit.

Voltage Sensing Relays (VSR) vs. DC-DC Chargers

While we still stock reliable BEP Voltage Sensing Relays (VSR) for simple, cost-effective dual-battery setups in older vehicles, a dedicated DC-DC charger is highly recommended for any setup utilising Lithium (LiFePO4) batteries. Lithium requires a specific charging profile that only a DC-DC charger can provide safely. Browse our selection today to find the perfect charging solution for your setup and enjoy the peace of mind that comes with a perfectly maintained battery bank.