A DC-DC battery charger is a powerful tool that keeps your leisure battery charged while you drive, ensuring you're ready to relax and enjoy nature once you park for the night.
What Is a DC-DC Battery Charger?
A DC-DC (or battery-to-battery) charger connects your leisure battery (also known as a “House Battery” to your vehicle's alternator via the vehicle’s starter battery. While the alternator recharges the starter battery, the DC-DC charger charges your leisure battery. This is essential since alternators output variable voltages, which can damage sensitive batteries if left unmanaged. Victron DC-DC Chargers work with any battery type including AGM, gel, and lithium.
DC-DC Charger vs. VSR: What's the Difference?
- VSR (Voltage Sensing Relay): A simple and cheap option, suitable for vehicles with lead-acid batteries and no complex alternator systems. VSRs act like switches, splitting the alternator's charge between your starter and leisure batteries when a specific voltage is detected.
- DC-DC Charger: Smarter and more versatile, these chargers are essential if:
- You have a lithium battery
- Your vehicle has a smart alternator (common in modern vehicles). These systems can output varying and extreme voltages, which only DC-DC chargers can regulate effectively.
Isolated vs. Non-Isolated DC-DC Chargers
- Non-Isolated: Shares a common ground with your vehicle's chassis—ideal for most setups.
- Isolated: Has no shared ground and is used in specialized cases, like ex-military vehicles or camper conversions with non-metallic habitation boxes.
But if you’re not sure – you should choose Isolated- these will work in all cases.
Starter Battery Voltage: Know Before You Buy
Check your vehicle's starter battery voltage (usually either 12V or 24V) and leisure battery voltage. Ensure the DC-DC charger you choose matches your battery types and system voltage. For example, you'd need a 12/24 charger for a 12V starter battery and 24V leisure battery system.
LUX Solar's DC-DC Charging Tool helps you select the correct charger and generates appropriate wiring kits to help you set it up quickly and easily.
Choosing the Right Size Charger
Your DC-DC charger’s capacity impacts how quickly your leisure battery will recharge. Consider:
- The desired recharge speed.
- Your battery's charging limits.
Our Victron Orion Smart DC-DC chargers are a popular choice. Easy to install and configure through Bluetooth, they provide efficient charging while being compact and durable.
Victron chargers do not come with cables to connect to your batteries - you can use our DC-DC Charging Tool to create the perfect prewired cable kit for your install.
Ready to Upgrade?
For high-quality, expert-designed systems, use our DC-DC battery charger kits. Each kit includes everything you need—charger, cables, fuses, and a detailed wiring diagram—to make installation seamless.