Sigenergy SigenStor Support — Battery Faults, EPS & SigenCloud Issues
One of the newest UK hybrid inverter brands — SigenStor systems combine solar, battery storage, and V2G capability. BMS communication faults, EPS not activating, SigenCloud offline, battery module errors — we diagnose Sigenergy systems at the engineering level. Remote-first. Evidence-led. Independent from Sigenergy and from your installer.
Most solar faults are diagnosed remotely in a single session. Tell us what you're seeing and we'll work it out.
Book a Remote Diagnostic — from £75 → See the Solar Health PlanSafety: do not open inverter or battery enclosures. If you smell burning or see arcing, isolate at the consumer unit and call 999.
Common Sigenergy problems we diagnose
Every fault below has a proven diagnostic path. Click through for the specific page or book a diagnostic if you're unsure.
Modules stuck at low SoC despite solar generation. Working mode misconfiguration, BMS communication fault, or grid code protection blocking charge.
See diagnostic guide →SigenCloud reports a battery module communication fault. Transient dropout from power cycle, firmware mismatch between modules, or hardware fault in BMS.
See diagnostic guide →Battery module not responding to SigenStor inverter. Check SigenCloud alarm log for exact fault code. Power cycle resolves most transient faults.
See diagnostic guide →App or SigenCloud shows no data. Gateway lost internet connection after router change, WiFi password update, or firmware update that broke cloud connectivity.
See diagnostic guide →SigenStor gateway can't find network or stay connected. Requires 2.4GHz — many problems stem from 5GHz-only or band-steering routers.
See setup guide →New phone, lost account access, or firmware update broke app connectivity. We reconfigure app settings and restore portal access.
See diagnostic guide →Backup power not available during power cut. EPS disabled, wiring issue, or SoC below minimum threshold.
Guide →SigenStor disconnecting from grid due to G98/G99 fault. Voltage, frequency, or isolation error.
See diagnostic guide →SigenStor not generating from panels. DC string fault, inverter protection trip, or grid code lock.
Guide →Output lower than expected. Panel soiling, string fault, or firmware misconfiguration.
See diagnostic guide →Sigenergy fault code index
SigenCloud displays fault codes and alarms when system errors occur. Our diagnostic process covers all fault categories and alarm codes across SigenStor models.
What we do for Sigenergy owners
Remote Sigenergy Diagnostic
We review SigenCloud data, app settings, and error history to identify the exact fault without a site visit.
SigenStor System Recovery
SigenCloud access lost, portal locked, or firmware misconfiguration. We recover monitoring and rebuild documentation.
On-Site Sigenergy Repair
BMS cable fault, battery module replacement, inverter repair, EPS wiring validation. Targeted visit — no guesswork on arrival.
SigEnergy datasheets, manuals & warranty PDFs
Download datasheets, installation manuals and warranty documents for SigEnergy hybrid inverters and battery systems. Self-hosted and always current.
SigEnergy fault code index
Seeing an error code on your SigEnergy inverter? Our fault code index explains what each code means, common causes, and safe next steps.
About Sigenergy SigenStor systems
Sigenergy is a relatively new UK market entrant (from 2022 onward) with advanced hybrid inverter and modular battery architecture. The SigenStor inverter series (5–12kW single phase) combines solar MPPT, battery management, and grid connection in one unit. The system pairs with modular SigenStor Energy Storage System (5–30kWh) for scalable capacity. A key differentiator is native V2G (vehicle-to-grid) and V2H (vehicle-to-home) capability built into every system.
The SigenCloud portal and Sigenhome app provide monitoring and configuration. As a newer brand, firmware updates are frequent and can sometimes affect connectivity. Common issues include EPS (Emergency Power Supply) requiring correct wiring and enablement, grid code faults (G98 vs G99), BMS communication faults between battery modules, and SigenCloud connectivity drops after router changes.
If you're searching for Sigenergy battery not charging, SigenStor BMS fault, SigenCloud offline, Sigenergy EPS not working, or Sigenergy V2G issues, STS provides independent diagnostic and repair support across the UK — not affiliated with Sigenergy Ltd or your installer. We diagnose at the engineering level using portal data, app screenshots, and on-site testing where needed.
Compare Sigenergy against other brands: Sigenergy vs GivEnergy, Sigenergy vs AlphaESS, Sigenergy vs Fox ESS, Tesla Powerwall vs Sigenergy.
Sigenergy questions answered
Common causes are incorrect working mode settings in the SigenCloud or Sigenhome app, a BMS communication alarm between battery modules and the inverter, or a grid code fault limiting solar export. Check the SigenCloud alarm log for the specific fault code. If the battery has a BMS communication alarm, a full power cycle (inverter off, battery modules off at the isolator, wait 60 seconds, battery modules on, then inverter) resolves most transient communication faults.
Sigenergy EPS (Emergency Power Supply) requires the backup circuit to be wired to the dedicated EPS output terminal — not the main load output. EPS mode must also be enabled in the SigenStor settings via SigenCloud. If both conditions are met but EPS still didn't activate, check the battery SoC at the time of the outage — if it was below the minimum EPS threshold (typically 10–20%), the system will not engage backup mode to protect the battery.
SigenCloud disconnects when the SigenStor gateway loses its internet connection. This happens after router changes, WiFi password updates, or if the system's WiFi dongle has dropped signal. Check the LED indicators on the SigenStor unit — a solid network LED means connected. Power cycling the inverter (AC isolator off, wait 30 seconds, back on) often restores the cloud connection. If the LED stays unlit, you may need to reconfigure the WiFi settings via the Sigenhome app.
Yes. Sigenergy BMS alarms between modular battery units and the SigenStor inverter are recorded in the SigenCloud event log. We review the alarm history to determine whether the fault is a transient communication dropout (often cleared by power cycle), a firmware version mismatch between modules, or a hardware fault in a specific battery module. Most BMS communication faults on Sigenergy systems are resolved remotely.
V2G (vehicle-to-grid) allows an electric vehicle's battery to send power back to your home or the grid. Sigenergy is one of the few UK hybrid inverters with native V2G capability built in. However, V2G requires a compatible vehicle and charger — not all vehicles support it yet. We provide guidance on V2G configuration and help troubleshoot connection issues between the vehicle, charger, and inverter.
STS supports all major inverter and battery brands — not just Sigenergy. If you have a mixed-brand system or are comparing options, visit the brand hub.
Browse all 19 brands →Ready to fix your Sigenergy system?
Tell us what's happening. We'll review your details and come back with a clear diagnosis path — usually same day.