What does error W31 mean on a DEYE inverter?

W31 means: Battery Communication Warning. The BMS connection is unstable, or the BMS data is abnormal.

Is error W31 a fault or a warning?

W31 is a warning: the red LED flashes and the unit keeps running. Fix the underlying condition before it escalates.

How do I clear or fix error W31?

1. Check whether the BMS connection is stable.

W31

DEYE inverter error W31

Battery Communication Warning

Warning — the red LED flashes and the inverter keeps running. Deal with it before it escalates.

SUN SG01HP3/SG02HP3 Hybrid

InverterWarning

Also applies to:SUN-5K-SG01HP3-EU-AM2SUN-6K-SG01HP3-EU-AM2SUN-8K-SG01HP3-EU-AM2SUN-10K-SG01HP3-EU-AM2SUN-12K-SG01HP3-EU-AM2SUN-15K-SG01HP3-EU-AM2SUN-20K-SG01HP3-EU-AM2SUN-25K-SG01HP3-EU-AM2+9

What it means

Battery Communication Warning — Battery_comm_warn - abnormal communication between the inverter and the battery.

Cause: The BMS connection is unstable, or the BMS data is abnormal.

How to fix it

Check whether the BMS connection is stable
Check whether the BMS data is abnormal.

Source: sun-12k-sg01hp3-eu-am2-manual.pdf, p.48 · sun-29.9-30-35-40-50k-sg01hp3-eu-bm3-4-20260224-en-manual.pdf, p.49 · sun-60-70-75-80k-sg02hp3-eu-em6-20260224-en-manual.pdf, p.49

Frequently asked questions

What does error W31 mean on a DEYE inverter?: W31 means: Battery Communication Warning. The BMS connection is unstable, or the BMS data is abnormal.
Is error W31 a fault or a warning?: W31 is a warning: the red LED flashes and the unit keeps running. Fix the underlying condition before it escalates.
How do I clear or fix error W31?: 1. Check whether the BMS connection is stable.

Related error codes

Other codes on the SUN SG01HP3/SG02HP3 Hybrid

All SUN SG01HP3/SG02HP3 Hybrid codes

Prefer the full written guide? Read the complete DEYE inverter error-code guide

Compiled from official DEYE user manuals. Always consult your device manual and a qualified technician before performing repairs.