Split Charge Relay Setup
The simplest way to add a house battery to your van. Charges while driving with no solar panels needed.
Try this diagram
Load this example into the interactive editor to explore, customize, and learn.
Open in editorThe split charge setup is the foundation of any van electrical system. Your engine alternator charges a dedicated leisure battery through a DC-DC charger while you drive. The DC-DC charger isolates the house battery from the starter battery, preventing you from accidentally draining your engine battery.
This is the perfect starting point for a van conversion — no solar panels, no complex wiring. Just connect the alternator through a DC-DC charger to your leisure battery, add a fuse for protection, and you have 12V power for USB charging, LED lights, or a small fan. Many van builders start here and add solar later.
Components
| Component | Qty | Key Spec |
|---|---|---|
| Engine Alternator | 1 | 120A |
| DC-DC Charger | 1 | 30A |
| 100Ah Lithium Battery | 1 | 100Ah |
| 40A Main Fuse | 1 | 40A |
| USB Outlets | 1 | 5A |
