BE04 on a SolaX Power SolaX X1-Hybrid G4: BMS_LowerVolt - low voltage in battery system
Short answer
On a SolaX Power battery, BE04 means: BMS_LowerVolt - low voltage in battery system. The battery keeps running with some functions stopped.
Reviewed 24 September 2026 · 1 source
What it means
The manual says: BMS_LowerVolt - low voltage in battery system.
Part involved: Battery voltage / state of charge.
Likely causes:
- Battery BMS-reported condition; manual says contact SolaX (via installer).
Is it safe?
| Does the battery stop? | Partly |
|---|---|
| Severity | Warning |
The battery keeps running with some functions stopped.
Resetting itself: usually - clears once the battery recharges from PV or grid.
Manual reset: sometimes (battery activation/force charge).
What you can check
- Read and note the exact code and time from the inverter display or app (screenshot).
- Check the battery is switched on and not paused in the app.
- Check reserve/charge settings in the app; in cold weather charging may pause below 0 C.
- Where the SolaX manual says 'press the ESC key to restart the inverter', a homeowner can do that on the display. Steps that say 'disconnect PV+/PV-/battery' are for the installer only.
What the engineer will check
- Measure battery voltage.
- Force-charge / battery activation per manual.
- Check BMS alarms and cell imbalance.
- Check DC breaker and polarity.
Who to ask for: Battery installer.
Certification: Electrician competent in electrical energy storage (BS 7671 Chapter 57; IET Code of Practice for Electrical Energy Storage Systems), ideally the MCS battery installer (MIS 3012); brand-approved installer to keep warranty.
What you might notice
Sources
- X1-Hybrid-G4 3.0/3.7/5.0/6.0/7.5 kW User Manual Version 3.0 (Version 03, 2024-08-08), doc 320101081103 ↗ · 3.0 · page PDF p.126 · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026