Split charge relays are a cornerstone of electrical system design in campervans and motorhomes, ensuring that multiple batteries are charged efficiently while preventing drainage of the vehicle's starter battery. This technology allows for the separation and management of different battery banks, typically one for starting the engine and another (or more) for powering appliances and amenities within the living space. This article explores the functionality, benefits, and key considerations of using split charge relays in campervans and motorhomes.

What is a Split Charge Relay?

A split charge relay is an electrical device that automatically manages the charging process between a vehicle's starter battery and its leisure battery (or batteries). When the engine is running, and the starter battery is fully charged, the relay activates to allow charging of the leisure battery from the alternator. This ensures that the leisure battery is charged without compromising the starter battery's ability to start the engine.

Benefits of Split Charge Relays

Optimized Battery Management: The primary advantage of a split charge relay is its ability to ensure that the leisure battery is charged while the engine is running, without risking the depletion of the starter battery. This setup is crucial for campervans and motorhomes, where electrical demands for living comforts can be significant.

Simple and Efficient: Split charge relays are favored for their simplicity and efficiency. They are easy to install and operate automatically once set up, requiring minimal maintenance or manual intervention.

Cost-Effective: Compared to more complex battery charging systems, split charge relays offer a cost-effective solution for managing dual battery systems in vehicles.

Safety: By isolating the starter battery when the engine is off, split charge relays prevent accidental battery drainage, ensuring the vehicle can always be started. This adds an important safety layer, especially in remote locations.