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Fault guide · GivEnergy battery

GivEnergy CAN Communication Fault — Diagnostic Guide

Your GivEnergy inverter has lost communication with the battery over the CAN bus. The system may show STORAGE_WARN_BMS_COM_FAIL or STORAGE_ERROR_BMS_COM_FAIL — or simply show the battery as disconnected. This guide covers every cause in order of likelihood.
  • Covers all GivEnergy hybrid models
  • Remote and on-site causes both covered
  • Many CAN faults recoverable remotely
CAN faults are hard to diagnose without the event log

The exact sequence of events in your inverter's log — what codes appeared, in what order, and when — tells us whether this is a cable fault, firmware issue, or BMS protection event. We can review this remotely.

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Not affiliated with GivEnergy Ltd. Independent diagnosis and repair.

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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

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
WHAT IS CAN?

Controller Area Network

CAN bus is the communication protocol GivEnergy uses between the inverter and battery. It carries state of charge data, charge/discharge commands, temperature readings, and protection signals. Without it, the inverter cannot safely operate the battery.

WHAT BREAKS

The data link, not the battery

A CAN fault doesn't necessarily mean the battery is damaged. It means the communication channel has been interrupted. The battery cells themselves are usually fine — the system just can't talk to them. This distinction matters for whether the fix is remote or on-site.

WHAT YOU SEE

Fault codes in the portal

The portal event log will show STORAGE_WARN_BMS_COM_FAIL (warning level) or STORAGE_ERROR_BMS_COM_FAIL (error level). The battery may show as disconnected in the portal dashboard, with SoC reading zero or N/A.

Do not open the battery or inverter enclosure. The CAN cable connects to the outside of the battery and inverter at an accessible socket — checking that connection is safe. Do not remove any covers or access internal components. If you're unsure what you're looking at, contact a qualified engineer.
Start here
Quick checks

Before anything else — check these

Two checks that take under a minute and eliminate the most common causes immediately.

1
Check the battery is physically switched on

The GivEnergy battery has a power button on the side panel. If this has been accidentally turned off — after a power cut, during a house move, or by a household member — the battery will appear as disconnected and trigger a CAN fault. Press and hold the button until you hear a beep and the LED indicators illuminate.

Also check that the DC MCB isolator (the green or red handled switch between the inverter and battery) is in the UP / ON position. If this is down, no DC power flows between the battery and inverter.
2
Check the CAN/BMS cable connection at both ends

The CAN communication cable runs between a socket on the inverter (underside) and a socket on the battery (typically labelled BMS or CAN). Check that the connector is fully seated at both ends — it should click firmly into place. A partially connected cable is a common cause of intermittent CAN faults, particularly on newer installations where cables may not have been fully seated at commissioning.

Cause 1 — try first
Power cycle

Restart the inverter and battery

Many CAN faults — particularly those triggered by power interruptions, brief grid outages, or software glitches — clear themselves after a controlled restart of both the inverter and battery. This should always be the first active step after the quick checks above.

1
Isolate the DC MCB between battery and inverter

Find the green or red handled MCB switch between the inverter and battery. Move it to the DOWN / OFF position. This isolates DC power between the two units before shutdown.

2
Turn the battery off using the side button

Press and hold the button on the side of the battery until the LEDs go out. The battery is now off. Leave it off for at least 60 seconds — this allows the BMS capacitors to discharge and clears any latched fault states.

3
Turn the inverter off at the AC isolator

The AC isolator is the switch below the inverter on the wall. Turn this off. Wait 60 seconds. Both the inverter and battery are now fully powered down.

4
Power everything back up in reverse order

Turn the AC isolator back on first. The inverter will begin its startup sequence. Then turn the battery on using the side button — wait for the LED indicators to stabilise (typically green). Then move the DC MCB back to the UP / ON position.

After restart: Allow 5–10 minutes for the inverter and battery to re-establish communication. Check the portal event log for whether the BMS_COM_FAIL code has cleared. If the fault reappears within minutes of restarting, there is a persistent underlying cause — continue through this guide.
Cause 2
Physical — requires site visit

CAN cable fault — loose, damaged, or wrong polarity

If the power cycle doesn't resolve the fault, the CAN cable between the inverter and battery is the next suspect. This is a physical cable and physical faults require a site visit to rectify — but a remote diagnostic can confirm the cable is the likely cause first.

Common cable fault types

Partially unseated connector — cable appears connected but isn't clicked fully home. Most common on new installations.
Wrong polarity — CAN cable reversed at one end. Causes immediate and persistent BMS_COM_FAIL from first boot.
Damaged cable — physical damage (crush, sharp bend, rodent). Can cause intermittent faults that are hard to reproduce.
Wrong termination — CAN bus needs correct termination resistors at each end. Missing or incorrect termination causes signal integrity issues, particularly on multi-battery stacks.

Signs pointing to a cable fault

Fault appeared immediately after installation (polarity or termination issue)
Fault is intermittent — clears after restart then returns within hours or days
Fault appeared after physical work near the inverter or battery (cable disturbed)
Multiple batteries in a stack — only one or some are showing comms fault
Power cycle clears the fault temporarily but it always returns
What you can safely check yourself: Visually inspect the CAN cable connector at the outside of the battery and the underside of the inverter. Confirm it is fully seated and the locking clip is engaged. Do not open any covers. If the cable appears connected but the fault persists, the issue is likely inside the connector or the cable itself — a qualified engineer needs to test continuity and check termination.
Cause 3 — common after updates
Common after updates

Firmware mismatch between inverter and battery

The GivEnergy inverter and battery run separate firmware versions that must be compatible with each other. If the inverter firmware is updated but the battery firmware isn't — or vice versa — the CAN protocol version can become incompatible and communication breaks.

How to check firmware versions

Inverter firmware

Go to givenergy.cloud → My Inverter → Software. The current firmware version is shown here. GivEnergy will also show whether an update is available for the inverter.

Battery firmware

Battery firmware version is visible in the portal under My Inverter → Battery details. If the battery firmware shows as outdated or mismatched, it needs updating. Check the GivEnergy knowledge base for the firmware compatibility matrix for your models.

Remote firmware update (inverter)

If the inverter firmware needs updating, this can be done remotely via the portal. Go to My Inverter → Software and click Update if an update is available. The update takes 5–30 minutes — do not turn the system off during this process. If the update appears stuck after an hour, restart the inverter.

Before updating: Check the GivEnergy changelog for known issues with the target firmware version. Some firmware versions have introduced new bugs. Do not update if your system is currently working and you're investigating an unrelated fault — firmware updates can introduce new problems.

Battery firmware update (requires USB — installer task)

Battery firmware updates are done locally via a USB stick inserted into the battery's internal USB port. This requires opening the front cover of the battery, which is an installer task — do not attempt this yourself. Contact GivEnergy support to obtain the correct BMS_ARM.bin file and arrange for an engineer visit if a battery firmware update is required.

Safety: Battery local firmware updates involve isolating the DC MCB and opening the battery enclosure. This is live electrical equipment. Do not attempt this without the correct qualifications. Email GivEnergy support at support@givenergy.co.uk to request the firmware file and guidance.
Cause 4
BMS protection event

BMS protection event — battery locked itself out

The Battery Management System (BMS) can lock the battery into a protection state in response to events like over-voltage, under-voltage, over-temperature, or a short-circuit detection. When locked in a protection state, the BMS stops responding to the inverter's CAN requests — which is reported as a communication fault even though the cable is fine.

What triggers a BMS lockout

Over-discharge — battery depleted below minimum voltage, often after a prolonged grid outage with EPS running
Over-temperature — battery in a confined space with poor ventilation, particularly in summer
Charge voltage spike — inverter sent incorrect charge voltage during a firmware update or configuration change
Cell imbalance — individual cells have diverged significantly, triggering a BMS protection shutdown

Identifying a BMS lockout vs a cable fault

Check the portal event log for protection-related codes appearing immediately before the BMS_COM_FAIL code — over-voltage, under-voltage, or temperature warnings are key indicators
Check the battery LED status light — a red or flashing pattern on the battery itself indicates a BMS fault state, not just a comms issue
Check the battery temperature if accessible — batteries in garages in summer can overheat
Did the fault coincide with a grid outage? EPS running until battery is flat is a common BMS lockout trigger

Recovery from BMS lockout

Some BMS protection events clear themselves after a controlled power cycle (see the power cycle section above). Others — particularly over-discharge events — require the battery to be recovered with a slow charge before the BMS will accept normal operation. Contact GivEnergy support if a power cycle doesn't clear the fault and a BMS protection event is suspected.

See the red light / battery alarm guide →
Cause 5 — last resort
Hardware

Hardware fault — inverter CAN port or battery BMS board

If all the above have been checked and ruled out, the fault may be a hardware failure — either the CAN interface on the inverter, or the BMS board inside the battery. These are warranty-eligible repairs on systems within the manufacturer warranty period.

Inverter CAN port failure

The CAN transceiver on the inverter PCB can fail — particularly after lightning-induced surges or sustained over-voltage events. Signs include persistent BMS_COM_FAIL with a known-good cable, and the fault appearing on a new battery if the battery is swapped as a test.

GivEnergy inverter warranty: typically 5–10 years depending on model. Contact GivEnergy with a written diagnostic report to support a warranty claim.

Battery BMS board failure

The BMS board inside the battery can fail independently of the battery cells. This is a hardware fault inside the enclosure and requires an engineer visit. Do not open the battery yourself. Battery warranty is typically 5–10 years and covers BMS hardware failures.

A remote diagnostic and written engineer report identifying the fault strengthens any GivEnergy warranty claim significantly.

We provide written diagnostic reports for warranty claims

A written engineer report identifying the fault type and cause significantly strengthens GivEnergy warranty submissions. We can provide this as part of a remote diagnostic session.

Book diagnostic

This is a brand-specific version of our general battery communication fault guide, which covers all brands.

FAQ

GivEnergy CAN fault questions

STORAGE_WARN_BMS_COM_FAIL is a warning-level code — the system has detected a communication issue but hasn't entered a full error state yet. The battery may still be operating but with reduced confidence. Try the power cycle first. STORAGE_ERROR_BMS_COM_FAIL is the error-level equivalent, indicating the communication has been fully lost. Both codes point to the same root causes — the error version simply means the fault has persisted or is more severe.
Yes — solar generation is typically unaffected by a CAN communication fault. The panels and inverter continue to generate and export or supply the house. What stops is battery charging and discharging — the inverter cannot safely control the battery without the CAN link. Your solar generation figures in the portal should still be accurate even during a CAN fault.
An intermittent CAN fault that clears after restart but returns within hours or days typically points to either a marginally connected cable (partially seated connector that vibrates loose), a firmware incompatibility where the inverter and battery negotiate successfully on startup but lose sync during operation, or an intermittent BMS protection event triggering repeatedly. A remote diagnostic reviewing your event log over the past week can identify the pattern and narrow the cause.
In a multi-battery stack, each battery has its own BMS and CAN connection in a daisy-chain. If one battery has a CAN fault while others are fine, the fault is localised to that unit — its cable connection, its own BMS firmware, or a hardware fault on that specific battery. Check the CAN cable connection at both ends of the affected unit specifically. Also check its firmware version — it may need updating independently of the others.
Book

Still showing a CAN fault? We'll diagnose it.

Tell us what the portal shows, when the fault appeared, and what you've already tried. We'll review your event log and identify whether this is a cable, firmware, BMS, or hardware fault — before recommending any site visit.

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