Victron 500A smart shunt not holding % charge reading, always returns to 100%

[Graham2]

Hi, new member. I have a 500A smart shunt installed DIY. My % leisure battery charge remaining number does not hold. Connecting with the App next day (for example) I find my 93% has returned to 100%. There has been no charging, don’t have solar, engine not started, starter battery relay open (so starter battery leakage is not charging the leisure battery). With all systems off, the smartshunt App shows 0.0A in either direction. Everything else is OK, could I just have a settings error? I cannot rely on accumulated %, it should be stored in the shunt. Thank You.

[M_Lange (Matthias Lange - DE)]

Most likely you have some wrong settings, check this:

Battery monitor jumping to 100% or reporting a high SOC with low Volts / the BMS shuts down

This topic covers the reported SOC being out of sync with the actual battery voltage or state. It covers 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 and is often linked to mobile applications with small solar systems. The SOC jum…

And the manual:

4. Configuration