After fitting smartshunt SOC readings do not tally

Pixelplus1812#
Sun, 22 Mar 2026 13:34:55 +0000
DIY

I fitted a smartshunt and synchronised it when the battery showed 100%.

The panel of the Multiplus has a message “low battery”, the battery (Fogstar) says 88% and the GUI shows 100%.

I cannot find a Modbus register that corresponds to either the Multibus or the Fogstar.

The Smartshunt is recognised as a device.

I need a reliable SOC as I am implementing ESS mode 3 using a Shelly EM50. As the EM50 does not work correctly with V3.71 (3.80 should be ok I am told) I have an RPI3 doing the job for now.

Until I have an SOC that corresponds to the battery I cannot proceed.

Any help about SOC gratefully received.

2 posts - 2 participants