Campervan Split Charge and Lithium Battery Installation
A campervan split charge lets the engine charge the leisure battery as you drive without flattening the starter battery when you stop. Paired with a lithium leisure battery, it gives far more usable power for the weight. We fit DC to DC chargers and LiFePO4 batteries, with the settings and fusing to make them work together.
Older vans used a simple voltage-sensing relay between the batteries. Modern base vehicles often have smart alternators whose voltage drops while driving, which leaves a relay-fed leisure battery undercharged. A DC to DC charger solves that.
We are based at Shoreham Airport and cover the South Coast between Brighton and Southampton.
Choosing a split charge method
A DC to DC charger, such as a Victron Orion-Tr Smart, boosts and regulates the charge to the leisure battery whatever the alternator is doing, and can be set to a lithium profile. It also limits the current drawn, protecting the alternator. A relay can still suit an older van with a conventional alternator and a lead-acid leisure battery, but rarely suits lithium.
- DC to DC charger sized to the alternator and battery
- Engine-running signal wired for smart alternators
- Fuses at both batteries and correctly sized cable
Campervan lithium batteries
LiFePO4 leisure batteries offer much more usable capacity than lead-acid of the same weight and tolerate deep discharge. We supply and fit Fogstar LiFePO4 batteries and can fit a battery you already have. Every charging source, from the DC to DC charger to the solar controller and hook-up charger, is set to the same lithium profile, and a shunt monitor gives you a true state of charge.
Fogstar battery installation · Battery monitor installation
Cold weather and lithium
Lithium batteries must not be charged below freezing unless they have low-temperature protection or heating. If the van is used in winter, battery position and the battery's own protection are part of the plan, so the battery management can stop charging in the cold.
How the job runs
Tell us the van, its year and what is fitted now. We check the alternator type and existing wiring, then give you a written quote. When finished, we explain the settings and readings.
Bringing the whole system together
Cable size between the batteries matters more than people expect. The run from the front of a van to a rear leisure battery is long, and undersized cable costs charging current on every journey. We size it for the charger's output over the full length and fuse it at both ends.
Split charging rarely works in isolation. Most vans also have solar and many have hook-up, so the DC to DC charger, solar controller and mains charger all feed the same leisure battery. When they share settings and a shunt monitor counts what goes in and out, the battery stays healthy and you can see exactly how much power you have before a night off-grid.
Campervan solar panel installation
Frequently asked questions
Do I need a DC to DC charger in my campervan?
If the van has a smart alternator or you have a lithium leisure battery, almost certainly. It regulates charging that a simple relay cannot.
Can I put a lithium battery in my campervan?
Usually, yes, with chargers set for LiFePO4 and suitable protection. We check the existing equipment first.
Will a split charge drain my starter battery?
No. A properly wired split charge only charges the leisure battery when the engine is running.
How much does a split charge installation cost?
It depends on the van, cable runs and charger. We assess first and quote in writing.
Charge as you drive
Send the van make, model and year and what is fitted now, and we will come back with a written quote.