I have a GivEnergy system consisting of two batteries, two inverters and a controlling EMS (Energy Management System) which has not worked since Nov 2025. After six months I discovered Solar Tech Support, reached out to them and Ron phoned me back – how often do you get that service? Could not be more helpful – worked directly with me over the phone, outside what I would call normal working hours. Lucid explanations and we were able to discuss the issues and history using camera and email history. As this was a very rare setup, Ron was able to access an EMS expert in the field to confirm the solution. One sunny day in, I am now only paying for standing charge and a few pence for spikes in grid consumption while battery catches up with house demand.
Huawei FusionSolar Offline — Smart Dongle Reconnection & Monitoring Fix
- Smart Dongle WLAN-FE (SDongleA-05)
- 2.4GHz WiFi only — 5GHz not supported
- Inverter keeps generating while offline
Smart Dongle LED flashing red, FusionSolar not updating after reconnection, or dongle hardware suspected failed? We diagnose remotely in a single session.
Book your free remote diagnosticBack to Huawei hubIndependent — not affiliated with Huawei Technologies.
What a fantastic service. Had my fault diagnosed within minutes and actually managed to resolve the issue remotely within a few minutes more. This guy is like a “Solar Batman” helping consumers fix their problems using his extensive industry knowledge and expertise. Outstanding service. Thank you so much.
I sent a message on their website regarding a problem I have on my Givenergy system. Although not supplied by Ronald, I thought it was worth an email. Within the hour on a Saturday, he phoned and we discussed the problem. He logged in remotely and gave excellent advice. I'm too far away for his on-site help but he did diagnose the problem and was happy also to chat through my thoughts about an upcoming solar/battery install I'm planning. Great bloke.... if only he was nearer!
Thank you for your diligence. On this occasion the battery was able to be saved but they have given a route to hopefully arrange a repair from the manufacturer.
I can add to the list of customers who had already 'given up' on GivEnergy due to their appalling customer service, and that was before they went into administration. So you can imagine my desperation when, having changed my ISP and my Inverter, predictably, proving to be the only device that didn't connect automatically to my new network, I found zero prospect of any customer support with GivEnergy having called in the administrators just five days earlier! The salvation came from Solar Tech Support. My IT advisor stumbled across their web site and some very helpful tips for beleaguered GivEnergy customers, as well as an offer to provide direct assistance. Nothing ventured, I decided to drop them an E-Mail, with very low expectations based on my experience of GivEnergy customer support. Within an hour Ron had responded with some pin point advice, and after a few exchanges of E-Mails he had nailed the problem, enabling the combined efforts of my IT advisor and solar installer to resolve it and reconnect my Inverter. Thank you Solar Tech Support, and Ron in particular, for coming to the aid of a deserted and despondent GivEnergy customer. Expert, razor sharp advice and first class customer service, even though I wasn't officially a customer.
I've spoken to Ron a couple of times with issues with my Givenergy installation. Such a friendly knowledge guy very highly recommended. Thank you very much for resolving my issues
Your inverter is still generating. FusionSolar going offline means the monitoring link is broken, not the system itself. The SUN2000 inverter and LUNA2000 battery (if fitted) continue operating normally. What you lose is visibility — you cannot see generation data, battery status, or fault alerts until the Smart Dongle reconnects.
6-step FusionSolar reconnection guide
Start with a power cycle (step 3). If that doesn't work, reconnect the WiFi (step 4). If WiFi is unreliable at the inverter location, skip to the Ethernet fallback (step 6).
Confirm the inverter is still generating
Check the LED display on the front of the SUN2000 inverter. If it shows generation figures (watts or kilowatts), the inverter is running normally — the offline issue is purely a monitoring connectivity problem.
Inverter is fine. Problem is the Smart Dongle connection to FusionSolar. Continue to step 2.
Inverter has a separate issue. Check for fault codes and see our AFCI fault or inverter not turning on guides.
Check the Smart Dongle LED indicator
The Smart Dongle (model SDongleA-05, also called the WLAN-FE) is a small module plugged into the USB port on the bottom of the SUN2000 inverter. Check its LED:
If the dongle is not physically present, it may have been removed or never installed. The inverter will generate without a dongle but cannot send data to FusionSolar.
Power cycle the inverter and Smart Dongle
A power cycle clears temporary communication faults and forces the dongle to re-establish its connection. Follow this exact sequence:
Wait 5 minutes, then check FusionSolar. If data reappears, the issue was a temporary communication fault.
Reconnect the Smart Dongle WiFi via the FusionSolar app
You need to be physically near the inverter for this step. The FusionSolar app connects directly to the dongle's local WiFi network to reconfigure it.
The dongle supports 802.11b/g/n on 2.4GHz only (2.412–2.484 GHz). If your router uses a combined 2.4/5GHz network, the dongle may fail to connect. Create a separate 2.4GHz SSID or disable band steering.
Enable the management system connection
After reconnecting WiFi, stay in the Communication configuration screen:
This re-establishes the secure link between the Smart Dongle and the FusionSolar cloud. Wait 5–10 minutes, then check FusionSolar for live data. The dongle LED should turn solid green.
Data from the period the dongle was offline will be missing. If the inverter stored data locally during the outage, some historical data may backfill automatically — but this depends on the inverter model and firmware version.
If WiFi keeps failing — use an Ethernet cable instead
The Smart Dongle WLAN-FE has a 10/100M Ethernet (RJ45) port as well as WiFi. If WiFi is unreliable at the inverter location — common in garages, lofts, or buildings with thick walls — Ethernet provides a permanent, stable alternative.
If running a cable to the router is impractical, a powerline adapter pair (e.g. TP-Link AV600) can bridge the gap using your home's mains wiring.
Why FusionSolar goes offline — and why it matters
Huawei SUN2000 inverters use a Smart Dongle (SDongleA-05 WLAN-FE) to send generation, battery, and fault data to the FusionSolar cloud platform. The dongle connects to your home WiFi on the 2.4GHz band and maintains a persistent encrypted link to Huawei's servers. When you change your broadband provider, get a new router, or update your WiFi password, the stored credentials in the dongle no longer match and the connection drops. This is the single most common reason FusionSolar goes dark.
While the monitoring link is down, the inverter and battery continue operating normally — you do not lose any generation or storage capability. What you lose is visibility: you cannot see how much the system is generating, whether the battery is charging and discharging correctly, or whether any fault conditions have occurred. For homeowners on the Smart Export Guarantee (SEG) or time-of-use tariffs, monitoring data is also useful for verifying that battery dispatch and export schedules are working as configured.
If the steps above do not resolve the issue, the Smart Dongle hardware itself may have failed. Dongle failures are relatively uncommon but do occur, particularly after power surges or firmware update failures. STS can confirm whether the dongle needs replacing based on LED behaviour and FusionSolar account status. Replacement dongles are available from Huawei solar distributors in the UK.
FusionSolar offline — common questions
FusionSolar still offline after trying this guide?
Smart Dongle LED still red, FusionSolar not updating, or dongle hardware suspected failed? We diagnose Huawei monitoring issues remotely using your FusionSolar account data and dongle status. Most issues resolved in a single session.
- No fix, no fee
- Smart Dongle WiFi and Ethernet troubleshooting
- Dongle replacement advice if needed
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