Problem diagnosis · LuxPowerTek

Lux Power Octopus Charging Not Working — TOU Schedule, Clock Offset & Grid Charge Fix

Your Lux Power battery should be charging overnight on the cheap rate, but it's not. The portal shows the schedule is set, the battery has capacity, and the inverter is online — but no grid import happens during the off-peak window. This is almost always a TOU configuration issue, not a hardware fault.

Start diagnosis

LuxPower portal TOU schedule specialist
Octopus Go, Flux, Agile & Intelligent
BST/GMT clock offset resolution

Battery not charging on the cheap rate?

Most LuxPowerTek charging failures are TOU schedule configuration errors. We diagnose and fix them remotely via the LuxPower portal — usually same day.

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Independent — not affiliated with LuxPowerTek.

5.0

13 Trustpilot reviews

Trustpilot Google

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.

Ian · May 2026 Trustpilot

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.

Sree · May 2026 Trustpilot

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

Dennis Brown · May 2026 Trustpilot

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)

Tony Deacon · May 2026 Trustpilot

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

Phill · May 2026 Trustpilot

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

michael fairhurst · May 2026 Trustpilot

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.

Mr Machin · May 2026 Trustpilot

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.

Keith Ballard · Apr 2026 Trustpilot

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.

Hugh Speirs · Apr 2026 Trustpilot

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.

Christopher · Apr 2026 Trustpilot

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.

customer · Apr 2026 Trustpilot

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.

Andy Thomas · Apr 2026 Trustpilot

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!

Philip · Apr 2026 Trustpilot

Ian · May 2026 Trustpilot

Sree · May 2026 Trustpilot

Dennis Brown · May 2026 Trustpilot

Tony Deacon · May 2026 Trustpilot

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

Phill · May 2026 Trustpilot

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

michael fairhurst · May 2026 Trustpilot

Mr Machin · May 2026 Trustpilot

Keith Ballard · Apr 2026 Trustpilot

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.

Hugh Speirs · Apr 2026 Trustpilot

Christopher · Apr 2026 Trustpilot

customer · Apr 2026 Trustpilot

Andy Thomas · Apr 2026 Trustpilot

Philip · Apr 2026 Trustpilot

Cheap rate charging UHome BMS fault Lux Power hub →

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Key point: LuxPowerTek cheap-rate charging relies entirely on the TOU schedule in the LuxPower portal. If the schedule is wrong, the battery will never charge from the grid during off-peak hours — even though the inverter and battery hardware are working perfectly.

Diagnostics

5-step Lux Power charging diagnosis

When a LuxPowerTek battery fails to charge on a cheap-rate tariff, the problem is in the TOU schedule configuration — charge window timing, grid charge enable, clock offset, SoC target, or charge current limit. Work through these steps in order.

Check the TOU charge window in the LuxPower portal

Log into the LuxPower monitoring portal and open the Time of Use schedule. Verify that a charge window exists for the correct cheap-rate period:

Typical UK smart tariff windows

Octopus Go: 00:30–04:30 (4 hours cheap rate)

Octopus Flux: 02:00–05:00 (cheap import window)

Octopus Intelligent: 23:30–05:30 (extended window)

Octopus Agile: Variable — cheapest half-hours change daily

If no charge window exists, the inverter has no instruction to charge from the grid. The most common error is a schedule that was edited but never properly saved.

Confirm grid charge is enabled in the TOU settings

LuxPowerTek inverters have a separate grid charge toggle within the TOU schedule. Even with a correctly timed charge window, if grid charge is disabled the inverter will only charge the battery from solar — no grid import will occur during the cheap-rate window.

This toggle is frequently missed during initial setup or accidentally disabled after a firmware update. In the LuxPower portal, check the TOU settings for each configured time period — grid charge must be explicitly enabled on the period covering your cheap-rate window.

Some LuxPowerTek firmware versions have separate charge and discharge toggles per TOU period. Ensure the charge toggle is on and the source includes grid.

Check the BST/GMT clock offset on the inverter

This is the single most common cause of seasonal charging failures. The LuxPowerTek inverter has its own internal clock that may not follow UK daylight saving time automatically:

What happens in BST (March–October)

If the inverter clock stays on GMT, a charge window set for 00:30 actually fires at 01:30 BST. The cheap-rate period may already be half over — or the battery never reaches full charge before the window closes.

What happens in GMT (October–March)

If someone corrected the clock in summer by adding an hour manually, it will now be one hour ahead in winter — charging starts at 23:30 instead of 00:30, potentially at a higher rate.

Check the inverter time in the LuxPower portal under device settings. If it shows UTC or is one hour out, the clock offset needs correcting.

Verify the SoC target and minimum SoC threshold

The TOU charge window has a target SoC that tells the inverter when to stop charging. If the battery is already at or above this target when the cheap-rate window starts, the inverter will not charge:

• Charge SoC target: Set to 100% for Go and Flux to maximise cheap-rate import

• Minimum SoC threshold: If set too high (e.g. 50%), the battery may not discharge enough during the day to create headroom for overnight charging

• Battery already full: If solar production fully charges the battery during the day and the minimum SoC prevents discharge, the battery arrives at the cheap-rate window already at 100%

For Octopus Go and Flux, the standard configuration is 100% charge target with a 10–20% minimum SoC. Adjust minimum SoC based on your evening consumption needs.

Check the charge current limit and battery BMS status

If the schedule is correct but the battery still doesn't fully charge during the window, the issue may be the charge rate:

• Single UHome module: Maximum charge rate is approximately 1.44kW (30A at 48V) — a 2.4kWh module takes roughly 1.5 hours from empty to full

• Stacked modules: Combined charge rate increases, but the inverter charge current limit must be set to match the stack size

• Charge current too low: If the inverter's grid charge current is limited below the available stack rate, the battery may not reach 100% before the window closes

Also check the UHome BMS communication status in the portal. If the battery has a BMS communication fault, it will reject charge commands regardless of the schedule configuration.

Safety: Do not open the inverter or touch DC cabling. If the BMS is in a fault state, isolate at the DC switch and contact an engineer.

Why Lux Power cheap-rate charging breaks so often

LuxPowerTek systems rely entirely on the LuxPower monitoring portal for TOU schedule management. Unlike some inverters that have on-screen schedule configuration, Lux Power systems are configured remotely — which means the portal must be online and correctly synced for any schedule changes to take effect. If the portal connection drops or the inverter's WiFi logger loses connectivity, schedule updates may not reach the inverter.

The BST/GMT clock offset problem affects Lux Power owners twice a year. We see a spike in charging complaints every March when the clocks go forward and again in October when they go back. The fix is straightforward — correct the clock offset in the portal — but many owners do not realise the inverter clock is independent of their phone or computer time. Combined with the grid charge toggle (which defaults to off on some firmware versions), these two configuration items account for the vast majority of cheap-rate charging failures on LuxPowerTek systems.

Lux Power cheap-rate charging — common questions

Why isn't my Lux Power battery charging on Octopus Go overnight?

The most common causes are: no TOU charge window configured in the LuxPower portal, the grid charge toggle being disabled, or a BST/GMT clock offset causing the window to fire at the wrong time. If the inverter clock is one hour behind during British Summer Time, the charge window misses the cheap-rate period entirely.

What is the BST clock offset issue on LuxPowerTek inverters?

LuxPowerTek inverters do not always follow UK daylight saving time automatically. When the clocks go forward in March, the inverter clock may stay on GMT — meaning a charge window set for 00:30 actually fires at 01:30 BST. This is the single most common seasonal charging failure. Correcting the clock offset in the portal device settings resolves it immediately.

How do I set up Octopus Flux on my Lux Power system?

Octopus Flux has three key windows: cheap import (02:00–05:00), peak export (16:00–19:00), and standard rate outside those times. Configure a charge window for 02:00–05:00 with grid charge enabled and 100% SoC target. Then configure a forced discharge window for 16:00–19:00 to export at the peak rate. The minimum SoC threshold controls how much the battery retains for evening use.

Can you configure my Lux Power system remotely for a smart tariff?

Yes. We configure LuxPowerTek TOU schedules remotely via the LuxPower portal — Octopus Go, Flux, Agile, Intelligent, or any time-of-use tariff. Most configurations are completed in a single remote session from £75 with no site visit required. We verify the clock offset, grid charge toggle, SoC targets, and charge current limits as part of the setup.

What SoC target should I use for overnight charging?

For Octopus Go and Flux, set the charge SoC target to 100% to maximise cheap-rate import. This fills the battery completely during the off-peak window. For Octopus Agile where prices vary by half-hour, you may want to adjust the target based on expected solar generation — but for fixed-window tariffs, 100% is the standard recommendation.

Book

Lux Power battery not charging on the cheap rate?

Tell us your tariff and what the LuxPower portal is showing. We'll review the TOU schedule, clock offset, grid charge settings, and SoC thresholds — and fix it remotely.

Free remote diagnostic · no fix, no fee
TOU schedule configuration included
All UK smart tariffs supported

Call 07944 877 329 Book free diagnostic