# Connecting Orion-TR DC-DC Charger to Cerbo GX **URL:** \ **Category:** DIY\ **Tags:** rv, cerbo\_gx, vrm, diy\ **Created:** [5 December 2024 04:34 UTC](https://community.victronenergy.com/t/connecting-orion-tr-dc-dc-charger-to-cerbo-gx/14234 "2024-12-05T04:34:11Z")\ **Posts on this page:** 1\ **Showing post:** 5
**Author:** ![pwfarnell](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/pwfarnell/32/2341_2.png) [@pwfarnell](https://community.victronenergy.com/u/pwfarnell)\ **Post date:** [17 March 2025 22:22 UTC](https://community.victronenergy.com/t/connecting-orion-tr-dc-dc-charger-to-cerbo-gx/14234/5 "2025-03-17T22:22:15Z")
Hard to follow your diagram. In vehicles the negative connections between the engine batteries and house batteries and the chassis ground are at fault and connected wrong. Look at this sketch, you may not have all the devices shown. ![Why is my shunt misreading](https://europe1.discourse-cdn.com/victron/original/2X/c/cbc19c86c2e30eaaed3c6037e5cc91521b4b59fb.png) > [@Shunt / battery monitor not reading the correct SOC/ Amps, missing solar, decreasing daily or other misreading problems](https://community.victronenergy.com/t/shunt-battery-monitor-not-reading-the-correct-soc-amps-missing-solar-decreasing-daily-or-other-misreading-problems/87): > > This topic covers the SOC / Amps reported by BMV battery monitors, SmartShunts, Lynx BMSs and Lynx Shunts and will just be called shunt below. It is also assumed that the shunt is monitoring the domestic / house / cabin battery bank and not engine start / bow thruster / winch / caravan mover battery banks. The problems may be one or more of the following The SOC decreases daily despite the solar charger or other charger(s) working. The SOC increasing when discharging and falling when charging… --- _[View the full topic](https://community.victronenergy.com/t/connecting-orion-tr-dc-dc-charger-to-cerbo-gx/14234)._