Can not get the smartshunt to autosyncronise

Tansel
Sat, 25 Apr 2026 06:34:29 +0000
DIY

Hi there,

First the system summary (on a 38ft boat):

2x225Ah (new) Mastervolt AGM batteries in parallel as service bank

2x340W solar panels in parallel

Victron SmartShunt 500/50

Victron SmartBatterySense

Victron MPPT 100/50 only charging service bank

Three victron items above are networked and communicating properly

Victron phoenix smart 3000VA inverter (switch operated, mostly in off state)

Shunt installation is correct: single cable from battery terminal to shunt

Cables are properly sized: 70mm²

The parameters on devices:

MPPT (made as preset for the batteries)

Absorbtion voltage is 14.25V as Mastervolt specified marked on the batteries and documents

Float voltage is 13.8V as Mastervolt specified marked on the batteries and documents

Temperature compensation is -30mV/°C as Mastervolt specified marked on the batteries and documents

Equalization disabled

Re-bulk voltage offset: 0.40V

Absorbtion duration: Adaptive

Max. absorbtion time: 5hrs

Tail current: 9A

SmartShunt

Battery Capacity: 450Ah

Charged voltage: 13.8V (also tried 13.6V and 14.0V in efforts to get autosync working, but didn’t)

Discharge floor: 50%

Tail current: 2%

Charged detection time: 3m

Peukert exponent: 1.11

Charge efficiency factor: 96%

Current treshold: 0.10A

Time-to-go averaging periond: 3m

Just after install, zero current calibration was done.

The voltage readings from all victron componentes as well as boat’s control panel are consistent all the time. Since I am in the Aegean region, around noon time everyday I get the SOC 100% and float state everyday. My nightly loads are minimal and since batteries are new I read around 12.7-12.8V in the mornings with SOC bwtween 92%-95%.

However, autosync count on shunt is at 0 (zero) for almost 10 days after the installation despite I have observed on shunt screen in app that three conditions for autosync are met several times. (voltage/tailcurrent/time).

Where am I doing wrong?

Thanks in advance for your comments and suggestions.

3 posts - 2 participants