How Do I Charge a Leisure Battery When Driving?

Charging while driving simply means charging your leisure battery whenever the engine is running — whether you’re on the road or idling. As long as the alternator is producing power, that energy can be used to recharge your leisure battery.

To do this safely and effectively, you need a dedicated device to manage the power coming from your vehicle’s electrical system. There are two main ways to achieve this:

• DC-DC Charger (Battery-to-Battery):

  The modern, all-in-one solution. A DC-DC charger regulates and boosts the alternator’s output, delivering a controlled, multi-stage charge tailored to your battery type, whether that’s Lead-acid, AGM, Gel, or Lithium.

  It works with both older and modern vehicles, including those with smart alternators and stop-start systems, making it the most versatile and future-proof option.

   

• Split Charge Relay:

  A simpler, more traditional method that links the starter and leisure batteries together when the engine is running, allowing power to pass between them.

  Because it doesn’t regulate or boost voltage, it’s best suited to older vehicles (typically pre-2015) with traditional alternators and standard wet lead-acid leisure batteries. It’s less effective with modern charging systems and not suitable for Lithium batteries.