# Another trouble shunt

**URL:** <https://community.victronenergy.com/t/another-trouble-shunt/41143>\
**Category:** DIY\
**Tags:** expert, marine, smartshunt\
**Created:** [28 July 2025 21:29 UTC](https://community.victronenergy.com/t/another-trouble-shunt/41143 "2025-07-28T21:29:28Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![noestlaurent](https://avatars.discourse-cdn.com/v4/letter/n/8e7dd6/32.png) [@noestlaurent](https://community.victronenergy.com/u/noestlaurent)\
**Post date:** [28 July 2025 21:29 UTC](https://community.victronenergy.com/t/another-trouble-shunt/41143/1 "2025-07-28T21:29:28Z")

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I have a sailboat. 400w solar panel, 55amp alternator, and 200w wind turbine. Victron shunt and MPPT SolarBoost. I bought a shunt to be able to track my consumption. When I’m only on solar, it’s fine, everything seems to be working. By the way, today, I’ve been using the engine for 9 hours, and my batteries have drained, depending on the shunt info. I’m attaching photos of the shunt. My alternator charges at 14.3v. Currently, my MPPT is showing 14.4v (charged) and only supplies the current I’m currently using; it’s no longer charging. My solar panels don’t charge when I start the engine (normal). I don’t know what to do with this system; nothing ever seems to work properly. The attached photos are in real time. The shunt not showing the same nomber vith the mppt

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**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:** [28 July 2025 21:45 UTC](https://community.victronenergy.com/t/another-trouble-shunt/41143/2 "2025-07-28T21:45:50Z")

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This sounds like the shunt is not wired up correctly. On boats and RVs the normal problem with alternator charging is the engine / hull / chassis ground is connected incorrectly. It needs to go to the system side of the shunt not the battery negative. See the image below from the DIY FAQ.

 ![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):
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> 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…

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**Author:** ![noestlaurent](https://avatars.discourse-cdn.com/v4/letter/n/8e7dd6/32.png) [@noestlaurent](https://community.victronenergy.com/u/noestlaurent)\
**Post date:** [28 July 2025 22:12 UTC](https://community.victronenergy.com/t/another-trouble-shunt/41143/3 "2025-07-28T22:12:48Z")

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I have 2 set on battery 26v for house and 1 for starter i use the image showing for connecting my shunt

 ![Screenshot_20250728_181036_Chrome](https://europe1.discourse-cdn.com/victron/original/3X/c/5/c5b62d3ac1d74f3f33178a6296efbe6ab2edbfe3.jpeg)