Tesla Powerwall backup not working during power cut
- Powerwall 2 and Powerwall 3
- Free remote-first diagnostic · no fix, no fee
- Not affiliated with Tesla
Tell us your Powerwall model, backup reserve setting, which circuits lost power, and whether the battery was fully charged. We review your Gateway configuration and backup status remotely.
Book your free remote diagnosticTesla Powerwall hubIndependent — not affiliated with Tesla Inc.
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.
When my GivEnergy system had an issue, I was completely left without support and had honestly lost all hope. Thankfully, I searched online and found Ron, which completely turned things around. After sending him a message, he responded incredibly fast and called me to assure me that he would get the problem fixed. I really admire his dedicated, supportive nature and his determination to find a solution. With this kind of outstanding attitude and customer service, he has absolutely secured a future customer in me.
Ron want out of is way to help, nothing was to much. He was very thorough in what he did Very knowledgeable I would highly recommend Ron and his company He did a fantastic job for me. if you have any problems, he'll do his best to help you out and resolve your problem. I wouldn't hesitate to recommend them
Ron took me through a diagnostic to confirm my GivEnergy Inverter had a fault. A common one as it turns out with the AC Inverter. As GivEnergy is defunct there is no immediate fix, aside from sourcing 2nd hand replacement. It may be that a fix becomes available over the summer which would make a lot of GivEnergy customers happy (Again)
Contacted Ron with a problem and he sorted it out quickly with no problems at all. Very knowledgeable on anything solar/ batteries. I would recommend him to anyone
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
Contacted Solar Tech Support in desperation. After explaining the issues I had with my system a diagnosis was made and a solution proposed. Fantastic service, even contacted a manufacturer to arrange replacement parts for me. Great communications, explained all they were doing and what I had to do, clearly and precisly. Followed up to confirm all was ok. Excellent service.
After GivEnergy went into liquidation, just my luck, my battery started playing up (internal board crashed). Contacted my installer - not interested! Found Solar tech support on a Google search. Sooo glad I found this company! Ron is extremely helpful and has plenty of experience. He soon confirmed what the fault was, and helped me to get my system up and running again. Now moved my GivEnergy account to Solar tech support, and will definitely use again if I have more issues. Unusual to find such a helpful company in these times, no morons reading scripts, just direct contact with the engineer.
Contacted Solar Tech Support when trying to understand what my Givenergy inverter problem might be and what might be my options. Received good/honest advise which backed up my thoughts.
Ron is a super star. Two months ago my GivEnergy battery failed a firmware upgrade leaving it a brick. My installer couldn't/wouldn't fix it. GivEnergy couldn't/wouldn't fix it. Then they went into administration and all hope was lost. A flurry of emails later and Ron had diagnosed the fault (failed USB flash drive, something I'd suspected) and talked me through resolving it. Two months of nothing resolved in about 3 hours. It's great to work with someone who pays attention to the details, knows that they're doing (not just following a script) and gets stuff sorted without a fuss or up-charging.
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 (their Trustpilot reviews don't lie!). 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.
This company are a rare gem, I had a very unusual problem following a failed firmware upgrade on my GivEnergy kit. I then found out GivEnergy were in administration and had dismissed all their support staff! None of the usual fixes to try and restore my inverter comms would work, and I looked everywhere, forums, GivEnergy youtube support videos - even AI couldn't figure it out. My installer was talking about huge sums for system replacements, and being vague / evasive about if they'd even install replacement GivEnergy inverter. Enter Solar Tech Support, reassuring and knowledgeable from the very start, I've learnt loads about my solar system though the friendly chat while my engineer worked as he diagnosed the problem and figured out a fix procedure that I've not found anywhere else - amazing . If you need solar system repairs - especially if you like me have been left high and dry by GivEnergy, I cannot recommend this company enough. Give them a call.
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!
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.
When my GivEnergy system had an issue, I was completely left without support and had honestly lost all hope. Thankfully, I searched online and found Ron, which completely turned things around. After sending him a message, he responded incredibly fast and called me to assure me that he would get the problem fixed. I really admire his dedicated, supportive nature and his determination to find a solution. With this kind of outstanding attitude and customer service, he has absolutely secured a future customer in me.
Ron want out of is way to help, nothing was to much. He was very thorough in what he did Very knowledgeable I would highly recommend Ron and his company He did a fantastic job for me. if you have any problems, he'll do his best to help you out and resolve your problem. I wouldn't hesitate to recommend them
Ron took me through a diagnostic to confirm my GivEnergy Inverter had a fault. A common one as it turns out with the AC Inverter. As GivEnergy is defunct there is no immediate fix, aside from sourcing 2nd hand replacement. It may be that a fix becomes available over the summer which would make a lot of GivEnergy customers happy (Again)
Contacted Ron with a problem and he sorted it out quickly with no problems at all. Very knowledgeable on anything solar/ batteries. I would recommend him to anyone
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
Contacted Solar Tech Support in desperation. After explaining the issues I had with my system a diagnosis was made and a solution proposed. Fantastic service, even contacted a manufacturer to arrange replacement parts for me. Great communications, explained all they were doing and what I had to do, clearly and precisly. Followed up to confirm all was ok. Excellent service.
After GivEnergy went into liquidation, just my luck, my battery started playing up (internal board crashed). Contacted my installer - not interested! Found Solar tech support on a Google search. Sooo glad I found this company! Ron is extremely helpful and has plenty of experience. He soon confirmed what the fault was, and helped me to get my system up and running again. Now moved my GivEnergy account to Solar tech support, and will definitely use again if I have more issues. Unusual to find such a helpful company in these times, no morons reading scripts, just direct contact with the engineer.
Contacted Solar Tech Support when trying to understand what my Givenergy inverter problem might be and what might be my options. Received good/honest advise which backed up my thoughts.
Ron is a super star. Two months ago my GivEnergy battery failed a firmware upgrade leaving it a brick. My installer couldn't/wouldn't fix it. GivEnergy couldn't/wouldn't fix it. Then they went into administration and all hope was lost. A flurry of emails later and Ron had diagnosed the fault (failed USB flash drive, something I'd suspected) and talked me through resolving it. Two months of nothing resolved in about 3 hours. It's great to work with someone who pays attention to the details, knows that they're doing (not just following a script) and gets stuff sorted without a fuss or up-charging.
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 (their Trustpilot reviews don't lie!). 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.
This company are a rare gem, I had a very unusual problem following a failed firmware upgrade on my GivEnergy kit. I then found out GivEnergy were in administration and had dismissed all their support staff! None of the usual fixes to try and restore my inverter comms would work, and I looked everywhere, forums, GivEnergy youtube support videos - even AI couldn't figure it out. My installer was talking about huge sums for system replacements, and being vague / evasive about if they'd even install replacement GivEnergy inverter. Enter Solar Tech Support, reassuring and knowledgeable from the very start, I've learnt loads about my solar system though the friendly chat while my engineer worked as he diagnosed the problem and figured out a fix procedure that I've not found anywhere else - amazing . If you need solar system repairs - especially if you like me have been left high and dry by GivEnergy, I cannot recommend this company enough. Give them a call.
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!
⚡ Safety Warning
Do not open your inverter or interfere with DC cabling. Solar panels produce live DC voltage whenever exposed to light. Always use your DC isolator switch and contact a qualified solar engineer for hands-on fault diagnosis.
Step-by-step backup fault diagnosis
Work through these steps in order. Step 1 checks the simplest cause — backup reserve too low. Step 2 verifies your circuits are backed-up. Steps 3–6 cover Gateway contactor, Storm Watch, load capacity, and power cycling.
Open the Tesla app → Settings → Power → Backup Reserve. This is the percentage of battery that is kept in reserve for power cuts — the Powerwall will not discharge below this level during normal operation. Minimum recommended is 20%. If the reserve is set too high (e.g. 60%), or the battery is at 65% SOC and the reserve is 60%, the Powerwall will only have 5% usable capacity during a power cut. When the reserve is below 20%, the battery may not store enough energy to sustain critical loads during long outages. Check your current reserve and your home's daily consumption — ensure the reserve leaves enough headroom for backup power.
The Gateway has a contactor that switches your home between grid and battery during an outage. Only circuits wired BEHIND the Gateway breaker receive backup power. Circuits that bypass the Gateway — such as a garage, external building, or a separate immersion heater circuit — will lose power during outages. During a power cut (or a test), walk around and note which lights and sockets work — these are backed-up. Critical appliances like your boiler, heating, fridge, and lights should be on backed-up circuits. If they are not, they will have no power during an outage. Contact your installer to review your wiring diagram and confirm which circuits are protected.
The Gateway's contactor is an electromagnetic switch that isolates your home from the grid and connects the Powerwall when power drops. If it gets stuck or fails, it cannot switch — you will have no power even though the battery is charged. During a power cut, listen for a clicking sound near the Gateway within 1–2 seconds. If you hear a click, the contactor is engaging. If there is no click or a delayed click, the contactor may be faulty. Also check distance between Gateway and Powerwall — if they are more than 30 metres apart or have poor network connectivity, communication latency can prevent reliable switching. The Gateway must detect the grid loss within milliseconds to switch on time.
Storm Watch is available on UK Powerwalls and integrates with the Met Office forecast. When enabled, the Powerwall auto-charges to 100% when severe weather is forecast for your area, bypassing the backup reserve and maximising capacity before storms. Enable it in the Tesla app → Settings → Storm Watch. If disabled and a storm is approaching, the battery may only charge to the backup reserve level (e.g. 20%), not to 100%. When a power cut occurs, the battery will run out of energy faster than expected. Enable Storm Watch before severe weather season to ensure the system pre-charges to full capacity.
Powerwall 2 continuous output: 5kW. Powerwall 3 continuous output: 11.5kW. If your backed-up loads exceed this rating, the Powerwall will overload and shut down, cutting all power. Common high-draw appliances: electric showers (7–10kW), immersion heaters (3kW), kettles (2–3kW), electric cookers (10kW+). During a power cut, if the Powerwall cuts out when you turn on the shower, that confirms an overload. The solution is to reduce simultaneous load during backup, wire high-draw appliances on non-backed-up circuits, or install additional Powerwall units for higher capacity.
Turn off the Gateway circuit breaker, wait 30 seconds, turn it back on. Allow 5 minutes for the system to reconnect. Test backup by briefly switching off the main grid breaker — the Powerwall should power the home within 2 seconds. The Tesla app should show "Your Home Is Backed Up" and display power flow from the battery. If the Powerwall cycles on/off repeatedly during this test, there may be a firmware issue, a load that is too high, or a contactor fault. If it does not switch at all within 5 seconds, the Gateway may have a hardware fault. Contact STS for a remote diagnostic — we review your Tesla app backup status, firmware, and home consumption data.
Tesla Powerwall backup — how islanding works
When a power cut occurs, the Gateway detects the loss and opens its internal contactor within milliseconds, isolating your home from the grid. The Powerwall then forms a microgrid — it powers your backed-up circuits independently, continuing to operate even if the Tesla app is offline or the internet connection drops. This islanding process is what keeps your home functioning during an outage. The Powerwall operates at its continuous rating (5kW for PW2, 11.5kW for PW3) and the backup reserve ensures enough energy is available when the grid fails. If the contactor does not switch within 2 seconds, or if your backup reserve is too low, the backup will fail.
In the UK, Powerwall backup installations must comply with G98/G99 islanding requirements — regulations that govern how battery systems can safely isolate from the grid and operate independently. These standards require the contactor to switch within a strict timeframe, ensure the system can detect a grid fault, and prevent export to the grid during an outage. The Gateway and Powerwall are designed to meet these requirements out of the box, but wiring and configuration matter — if your installation bypasses the Gateway or uses non-standard backup circuits, islanding may fail. STS diagnoses backup faults remotely by reviewing your Tesla app data, backup status, and Gateway firmware to determine if the issue is a settings problem or a hardware fault.
Powerwall backup — common questions
Powerwall backup still not working?
If you have checked the backup reserve, verified your circuits are backed-up, tested the contactor, and the Powerwall still will not provide backup — the issue may be a Gateway hardware fault, a firmware bug, a communication lag, or an overload condition. We review your Tesla app backup status, Gateway firmware, and home consumption data remotely. Independent from Tesla and your installer.
- Not affiliated with Tesla Inc
- Free remote diagnostic · no fix, no fee
- On-site visits available across the UK
Got a solar fault or need a quick answer? Drop us a message — we usually reply within a few minutes. Mon–Fri, 9am–7pm.