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Problem diagnosis · Off-Grid · All brands

Low voltage disconnect — loads cutting off

Your off-grid system is cutting power to loads — lights, fridges, sockets — because the battery voltage has dropped below the LVD threshold. It may recover shortly after, only to trip again under load.

The cause is usually one of four things: the LVD threshold is set too high, high-current loads are causing voltage sag, cold weather has reduced battery capacity, or the battery bank is undersized for the daily load.
  • LiFePO4 and lead-acid covered
  • Voltage sag is often the cause
  • Free remote diagnostic · no fix, no fee
Loads keep cutting off in your off-grid system?

We diagnose LVD trips remotely — checking your threshold settings, voltage sag under load, battery temperature, and daily energy balance to find the root cause and recommend the fix.

Get free remote help — no fix, no feeAll problem guides

Independent — not affiliated with any brand or manufacturer.

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

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
Why LVD trips are more common in winter

LVD is a protection mechanism, not a fault

The low voltage disconnect exists to prevent battery over-discharge. The problem is either that it is triggering when it shouldn't (wrong threshold or voltage sag), or that it is triggering correctly because the battery genuinely doesn't have enough capacity for the load. Diagnosing which of these applies determines the fix.

UK peak sun hours drop from 4–5 per day in summer to 1.5–2.5 per day in December and January — and low sun angles mean the first and last hours of generation are marginal.

Batteries in unheated outbuildings or sheds can drop to 5–10°C, reducing usable capacity by 15–20% and increasing internal resistance so that voltage sag is worse under the same load.

A 10 kWh battery bank delivering 8 kWh usable in summer may only deliver 6.5 kWh in winter — and sag under load will trip the LVD sooner. If your system triggers LVD in winter but never in summer, the sizing and temperature combination is the diagnosis: the fix is insulation, additional capacity, load reduction, or a generator backup charge source.
Step 1 — settings
Most common fix

Check the LVD threshold setting on the MPPT controller or inverter

Compare your LVD setting against the correct value for your battery chemistry:

RECOMMENDED LVD VOLTAGES BY CHEMISTRY

Reference values

12V LiFePO4: LVD 11.5–12.0V · Reconnect 12.5–13.0V
24V LiFePO4: LVD 23.0–24.0V · Reconnect 25.0–26.0V
48V LiFePO4: LVD 46.0–48.0V · Reconnect 50.0–52.0V
12V AGM/GEL: LVD 11.5–11.8V · Reconnect 12.5–12.8V
12V Flooded: LVD 11.8–12.0V · Reconnect 12.8–13.0V

If the controller is set to a sealed lead-acid profile but you have lithium, the LVD will be set to the SLA value — which may be too high for LiFePO4. Switch to a custom profile and set LVD manually from the battery manufacturer's specification sheet.

Step 2 — measurement

Measure actual battery voltage under load to check for voltage sag

Voltage sag is the most misdiagnosed cause of LVD trips. The battery has capacity remaining, but the terminal voltage drops below LVD under load:

How to test

Use the MPPT monitoring app, VRM (Victron), or a multimeter to read battery voltage during a load event. Note the voltage at the moment of disconnection.

Confirming sag

If the voltage immediately recovers to a healthy level (e.g. jumps from 47V back to 51V the moment loads disconnect), the battery had capacity — the sag triggered LVD, not genuine depletion.

Sag magnitude

A well-sized battery bank should sag less than 2V under normal load. Sag of 3–5V under a 3kW load on a small 5kWh bank is common and means the bank is too small for that load.

Victron-specific

VRM shows a detailed battery voltage graph — look for sharp dips at the time of LVD events in the advanced history section.

Step 3 — loads

Identify loads drawing excessive current and causing voltage sag

Identify which load is active when LVD trips occur. High-current loads cause the most pronounced sag:

HIGH-DRAW LOADS TO CHECK

Reference draws

Kettle: 2–3 kW · 42–62A at 48V DC equivalent
Immersion / water heater: 2–3 kW · constant draw
Workshop tools (angle grinder, circular saw): 1.5–3 kW · surge on startup
Washing machine (heating cycle): 1.5–2.5 kW
Induction hob: 1–3 kW per zone
Fridge: 0.1–0.3 kW · compressor surge 3–5× running draw

Running a kettle and washing machine simultaneously on a small battery bank is a common LVD trigger. Stagger high-draw appliances or run them only during solar hours when the MPPT is also contributing current.

Step 4 — temperature
Often the missing piece

Check for cold-weather capacity loss reducing effective battery size

LiFePO4 capacity and internal resistance are both affected by temperature. A battery in an unheated space in winter is effectively smaller than its nameplate rating:

Capacity by temperature

Capacity at 25°C: 100% (rated capacity)
Capacity at 10°C: ~88–92% of rated
Capacity at 0°C: ~72–80% of rated
Capacity at −10°C: ~55–65% of rated — BMS will likely block charging entirely
Increased internal resistance: Means greater voltage sag per amp drawn at low temperatures — so LVD threshold is hit sooner even with the same load.

If LVD trips are concentrated in winter or at night, check the battery temperature. Insulating the battery enclosure or moving it to a heated space can recover 15–20% of winter capacity loss. See our cold weather battery guide for more detail.

Step 5 — system sizing

Resize the battery bank or adjust load schedule if the system is fundamentally undersized

If LVD trips frequently regardless of season or threshold setting, the battery bank is too small for the daily load. Use this sizing check:

BATTERY BANK SIZING FORMULA

Calculation

1. Total daily load (Wh) ÷ usable DoD (0.8 for LiFePO4, 0.5 for lead-acid)
2. Add 25% for inverter & cable losses
3. Divide by days of autonomy (1–3 typical for off-grid with generator backup)
= Minimum battery bank capacity (Wh)

Add battery capacity

Most lithium systems allow stacking additional modules — check battery compatibility list for parallel limits.

Reduce load

Swap resistance heating for heat pump alternatives. Replace incandescent or halogen with LED. Move washing to solar peak hours.

Add a generator

A generator backup charge input allows the battery to be topped up during sustained low-solar periods rather than relying on the battery alone.

FAQ

Low voltage disconnect — common questions

The most likely cause is voltage sag — the battery voltage drops below the LVD threshold under load even though the SoC is reasonable. Check what the voltage reads at the moment of disconnection: if it recovers immediately after loads disconnect, voltage sag is the cause. Fix: lower the LVD threshold slightly, reduce peak load current, or increase battery capacity to reduce sag per amp drawn.
For 12V LiFePO4: LVD 11.5–12.0V. For 24V: 23.0–24.0V. For 48V: 46.0–48.0V. These correspond to approximately 10–15% SoC. Setting LVD too high wastes usable capacity and causes trips at healthy SoC levels. Setting it too low risks the BMS triggering deep discharge protection instead. Check your battery manufacturer's specification for the exact recommended value.
Winter LVD trips combine reduced solar input and cold-weather capacity loss. Most effective fixes in order of cost: (1) insulate the battery enclosure to keep temperature above 10°C, (2) reduce high-draw loads during low-generation periods, (3) add a generator as a backup charge source for poor-weather days, (4) add more battery capacity, (5) add more solar panels to improve winter generation.
Yes — most MPPT controllers allow manual LVD configuration. For Victron SmartSolar, it's in VictronConnect under load output settings. For EPsolar/Tracer, it's via the front panel or PC software. For Renogy Rover, it's in the LCD menu. If the controller is set to a preset battery type (e.g. sealed lead-acid), the LVD will use default values that may not match your lithium battery. Switch to a custom profile and enter the LVD voltage from your battery spec sheet.
This is voltage sag under load. Terminal voltage under high current is lower than open-circuit voltage — if the controller reads 48V during a high-current event and your LVD is 48V, it disconnects loads even though true SoC is 20%. Once loads disconnect, voltage recovers to 51–52V, confirming there was capacity remaining. Solution: lower the LVD threshold by 1–2V so it only trips on actual low SoC, or reduce peak load current to reduce the sag magnitude.
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Loads keep cutting off in your system?

Tell us your battery voltage at the point of disconnection, your LVD threshold setting, and what loads were running. We'll identify whether it's a settings issue, voltage sag, or a sizing problem.

  • Free remote diagnostic · no fix, no fee
  • LVD settings, sag & sizing all covered
  • All MPPT controller brands supported

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