DC-DC Charger Not Charging? Step-by-Step Troubleshooter
Find out why your DC-DC charger isn't charging the auxiliary battery while you drive.
This follows the checks in our guide What Size DC-DC Charger Do I Need?. Work through one question at a time. You can go back or start over whenever you like.
Your answers so far
Safety: this troubleshooter is general information. Follow the maker's manuals. Work on 240V AC wiring, including inverter outputs and mains inlets, must be done by a licensed electrician. Have an auto electrician check high-current DC work if you're unsure.
Related guides
What Size DC-DC Charger Do I Need? 20A vs 25A vs 40A
Match your DC-DC charger to your battery size, alternator and cable run, with tips for smart alternators and solar input.
Read guide →
Dual Battery Wiring Diagram for a 4WD
A simple 4WD dual battery layout with a DC-DC charger, fuses and earths: how it works, DC-DC charger or VSR, the parts list and what to get right.
Read guide →