Alpha ESS inverter & battery error codes explained
Alpha ESS SMILE systems report inverter errors as six-digit numbers (such as 110021 Grid Loss Alarm) in the AlphaCloud app/web, while SMILE battery modules signal protection and error codes through their LED ring. Find your code below.
Safety first, please read
- Solar panels and batteries produce dangerous DC voltage whenever there is daylight or charge in the battery, even with the mains switched off. Electrical work on these systems must only be done by a licensed electrician.
- Never open the inverter or battery, and don't unplug, touch or adjust DC cables, connectors or isolators except for the owner shutdown steps in your manufacturer's manual.
- For an isolation/insulation fault, earth fault, arc fault, residual-current fault or battery over-temperature alarm, or any smoke, burning smell, hissing, swelling, leaking or water damage: only switch off if the manufacturer's procedure lets you do it safely, keep everyone clear, and call a licensed electrician or Total Solar.
- If there is fire or smoke, get everyone out and call 000. Tell the fire service there is a solar and battery system on site.
- Don't climb on the roof to check or clean panels. Do checks from the ground only.
Owner shutdown and restart (Alpha ESS)
Alpha ESS's SMILE5 manual gives this power-off order: switch off the AC breaker to the backup loads, then the AC breaker to the grid, then any PV switches, then the battery breaker on the inverter, then press and hold the battery's power button for 5 seconds and switch off the battery's breaker. Only do this if your installer has shown you how and it is safe.
- SMILE5 hybrid inverter (SMILE5-INV)
- SMILE-BAT-5P battery (protection codes, green LED flashing every 3 s)
- SMILE-BAT-5P battery (error codes, red LED flashing every 3 s)
SMILE5 hybrid inverter (SMILE5-INV) (44 codes)
100005BUS OVP1Fault
What it means: The equipment's self-checks found an internal problem (for example relays, measuring circuits, internal communication or power electronics). Some of these clear by themselves after a one-off event, but repeated alarms usually need a technician.
Likely causes:
- A one-off disturbance (for example a grid event)
- Internal component or circuit board fault
- Firmware issue
What you can safely do:
- Note the code, time and whether it clears by itself
- If your installer showed you the owner shutdown/restart procedure from the manufacturer's manual (summarised at the top of this page), you may restart the system once. Do not open covers or touch cabling.
- If the code returns or the system stays offline, call us. Internal faults are a warranty/technician job
100007Insulation faultSafety-critical
What it means: The inverter measured low insulation resistance between the solar/battery DC circuits and earth. In Australia this is treated as an earth fault alarm, and the system must be checked by a licensed electrician.
Likely causes:
- Damaged DC cable insulation (for example from rodents, UV or a pinched cable)
- Water in a DC connector, isolator or junction box
- A damaged solar panel or backsheet
- Heavy dew or rain can trigger it temporarily on marginal systems
What you can safely do:
- Do not touch panels, DC cables, rooftop isolators or the inverter's DC connectors
- If it clears by itself after the weather dries out, still report it, because repeated alarms point to a developing fault
- Book an electrician or call us. An insulation test needs specialist equipment
- If you see smoke, burn marks or smell burning, keep clear and call 000
100008GFCI faultSafety-critical
What it means: The inverter measured leakage (residual) current flowing to earth above its safety limit and disconnected. This can indicate damaged insulation somewhere in the system.
Likely causes:
- Damaged DC or AC cable insulation
- Moisture in connectors or equipment
- A one-off disturbance (if it happens once and never again)
What you can safely do:
- Don't touch cabling or equipment
- If it happens repeatedly, or together with an insulation/isolation alarm, call an electrician or us promptly
100010Grid relay faultFault
What it means: The grid relay check failed. Occasional events are usually caused by brief grid problems and clear by themselves. Persistent ones can indicate a relay fault.
Likely causes:
- A one-off disturbance (for example a grid event)
- Internal component or circuit board fault
- Firmware issue
What you can safely do:
- Note the code, time and whether it clears by itself
- If your installer showed you the owner shutdown/restart procedure from the manufacturer's manual (summarised at the top of this page), you may restart the system once. Do not open covers or touch cabling.
- If the code returns or the system stays offline, call us. Internal faults are a warranty/technician job
100012PV ReverseFault
What it means: A solar string or the battery appears to be connected with positive and negative swapped.
Likely causes:
- Polarity error during installation or maintenance
What you can safely do:
- Do not touch any DC wiring
- Call us or a licensed electrician
100025BAT OVPFault
What it means: The battery management system has reported a problem with battery voltage, current, cells or internal hardware and has limited or stopped battery operation.
Likely causes:
- Cell voltage or capacity imbalance
- Over-charge or over-discharge conditions
- Internal battery hardware (relay, sensor, circuit board) fault
- Firmware or configuration mismatch between battery modules
What you can safely do:
- Do not open the battery or touch its terminals
- Note the exact alarm text and time from the app
- Call us. Battery faults should be handled by the installer or manufacturer
100026BAT UVPInfo
What it means: The battery's state of charge or voltage is low, so the system has stopped discharging it to protect the cells.
Likely causes:
- Battery has been used down to its reserve level
- Several cloudy days with little solar to recharge
- Charging is disabled by the settings or by another fault
What you can safely do:
- Allow it to recharge from solar (or the grid, if your settings allow)
- Check the app for other alarms that could be stopping charging
- If it stays low for days in good sun, call us. Batteries left flat for long periods can be damaged
100027Battery loseFault
What it means: The inverter and battery (or parts inside the battery) have stopped talking to each other, so the battery may stop charging or discharging.
Likely causes:
- Battery switched off or in a protection state
- Loose or damaged communication cable
- Firmware or settings mismatch
What you can safely do:
- Check the battery's indicator lights and your monitoring app for other alarms
- Don't unplug or re-plug cables yourself
- Call us if it does not clear within a few hours
100030BAT1 discharge OCPWarning
What it means: The backup/EPS (off-grid) output is overloaded or abnormal, so the system has limited or switched off backup power.
Likely causes:
- Too many or too large appliances on backup circuits during an outage (for example ovens, air conditioners, pumps)
- High start-up surge from motors or compressors
- A short circuit on a backup circuit
What you can safely do:
- Switch off large appliances on backup circuits
- Wait for the system to retry (some models lock out for a period after repeated overloads)
- If it trips with only small loads on, or you suspect a short circuit, call an electrician
100038Output DC over currentFault
What it means: The inverter detected too much DC current in its AC output, which the grid standards don't allow, so it disconnected.
Likely causes:
- A one-off disturbance (if it is occasional)
- Internal measuring or power stage problem (if it repeats)
What you can safely do:
- If it happened once and the system recovered, keep an eye on it
- If it repeats, call us
100041Output DC over voltageFault
What it means: The inverter detected too much DC current in its AC output, which the grid standards don't allow, so it disconnected.
Likely causes:
- A one-off disturbance (if it is occasional)
- Internal measuring or power stage problem (if it repeats)
What you can safely do:
- If it happened once and the system recovered, keep an eye on it
- If it repeats, call us
100042Output shortWarning
What it means: The backup/EPS (off-grid) output is overloaded or abnormal, so the system has limited or switched off backup power.
Likely causes:
- Too many or too large appliances on backup circuits during an outage (for example ovens, air conditioners, pumps)
- High start-up surge from motors or compressors
- A short circuit on a backup circuit
What you can safely do:
- Switch off large appliances on backup circuits
- Wait for the system to retry (some models lock out for a period after repeated overloads)
- If it trips with only small loads on, or you suspect a short circuit, call an electrician
100043Output overloadWarning
What it means: The backup/EPS (off-grid) output is overloaded or abnormal, so the system has limited or switched off backup power.
Likely causes:
- Too many or too large appliances on backup circuits during an outage (for example ovens, air conditioners, pumps)
- High start-up surge from motors or compressors
- A short circuit on a backup circuit
What you can safely do:
- Switch off large appliances on backup circuits
- Wait for the system to retry (some models lock out for a period after repeated overloads)
- If it trips with only small loads on, or you suspect a short circuit, call an electrician
100046DC Input DisturbanceFault
What it means: The equipment's self-checks found an internal problem (for example relays, measuring circuits, internal communication or power electronics). Some of these clear by themselves after a one-off event, but repeated alarms usually need a technician.
Likely causes:
- A one-off disturbance (for example a grid event)
- Internal component or circuit board fault
- Firmware issue
What you can safely do:
- Note the code, time and whether it clears by itself
- If your installer showed you the owner shutdown/restart procedure from the manufacturer's manual (summarised at the top of this page), you may restart the system once. Do not open covers or touch cabling.
- If the code returns or the system stays offline, call us. Internal faults are a warranty/technician job
100052Backup ovpWarning
What it means: The backup/EPS (off-grid) output is overloaded or abnormal, so the system has limited or switched off backup power.
Likely causes:
- Too many or too large appliances on backup circuits during an outage (for example ovens, air conditioners, pumps)
- High start-up surge from motors or compressors
- A short circuit on a backup circuit
What you can safely do:
- Switch off large appliances on backup circuits
- Wait for the system to retry (some models lock out for a period after repeated overloads)
- If it trips with only small loads on, or you suspect a short circuit, call an electrician
100054Dc bus undervoltFault
What it means: The equipment's self-checks found an internal problem (for example relays, measuring circuits, internal communication or power electronics). Some of these clear by themselves after a one-off event, but repeated alarms usually need a technician.
Likely causes:
- A one-off disturbance (for example a grid event)
- Internal component or circuit board fault
- Firmware issue
What you can safely do:
- Note the code, time and whether it clears by itself
- If your installer showed you the owner shutdown/restart procedure from the manufacturer's manual (summarised at the top of this page), you may restart the system once. Do not open covers or touch cabling.
- If the code returns or the system stays offline, call us. Internal faults are a warranty/technician job
100058AFCI check protectFault
What it means: The equipment's self-checks found an internal problem (for example relays, measuring circuits, internal communication or power electronics). Some of these clear by themselves after a one-off event, but repeated alarms usually need a technician.
Likely causes:
- A one-off disturbance (for example a grid event)
- Internal component or circuit board fault
- Firmware issue
What you can safely do:
- Note the code, time and whether it clears by itself
- If your installer showed you the owner shutdown/restart procedure from the manufacturer's manual (summarised at the top of this page), you may restart the system once. Do not open covers or touch cabling.
- If the code returns or the system stays offline, call us. Internal faults are a warranty/technician job
100060Dsp selfcheckFault
What it means: There is a firmware, model or configuration mismatch between parts of the system, so it can't run normally.
Likely causes:
- Interrupted or partial firmware update
- Parts replaced with different firmware versions
- Incorrect model or country/region setting
What you can safely do:
- Don't try to reflash firmware yourself unless the manufacturer's app tells you to and it's an owner function
- Call us. We can arrange a firmware update or reconfiguration with the manufacturer
100122EEPROM R/W FailureFault
What it means: The equipment's self-checks found an internal problem (for example relays, measuring circuits, internal communication or power electronics). Some of these clear by themselves after a one-off event, but repeated alarms usually need a technician.
Likely causes:
- A one-off disturbance (for example a grid event)
- Internal component or circuit board fault
- Firmware issue
What you can safely do:
- Note the code, time and whether it clears by itself
- If your installer showed you the owner shutdown/restart procedure from the manufacturer's manual (summarised at the top of this page), you may restart the system once. Do not open covers or touch cabling.
- If the code returns or the system stays offline, call us. Internal faults are a warranty/technician job
100123DSP communication failureFault
What it means: The equipment's self-checks found an internal problem (for example relays, measuring circuits, internal communication or power electronics). Some of these clear by themselves after a one-off event, but repeated alarms usually need a technician.
Likely causes:
- A one-off disturbance (for example a grid event)
- Internal component or circuit board fault
- Firmware issue
What you can safely do:
- Note the code, time and whether it clears by itself
- If your installer showed you the owner shutdown/restart procedure from the manufacturer's manual (summarised at the top of this page), you may restart the system once. Do not open covers or touch cabling.
- If the code returns or the system stays offline, call us. Internal faults are a warranty/technician job
10014512V auxiliary power FaultFault
What it means: The equipment's self-checks found an internal problem (for example relays, measuring circuits, internal communication or power electronics). Some of these clear by themselves after a one-off event, but repeated alarms usually need a technician.
Likely causes:
- A one-off disturbance (for example a grid event)
- Internal component or circuit board fault
- Firmware issue
What you can safely do:
- Note the code, time and whether it clears by itself
- If your installer showed you the owner shutdown/restart procedure from the manufacturer's manual (summarised at the top of this page), you may restart the system once. Do not open covers or touch cabling.
- If the code returns or the system stays offline, call us. Internal faults are a warranty/technician job
100165data storage errorFault
What it means: The equipment's self-checks found an internal problem (for example relays, measuring circuits, internal communication or power electronics). Some of these clear by themselves after a one-off event, but repeated alarms usually need a technician.
Likely causes:
- A one-off disturbance (for example a grid event)
- Internal component or circuit board fault
- Firmware issue
What you can safely do:
- Note the code, time and whether it clears by itself
- If your installer showed you the owner shutdown/restart procedure from the manufacturer's manual (summarised at the top of this page), you may restart the system once. Do not open covers or touch cabling.
- If the code returns or the system stays offline, call us. Internal faults are a warranty/technician job
100166inverter circuit abnormalFault
What it means: The equipment's self-checks found an internal problem (for example relays, measuring circuits, internal communication or power electronics). Some of these clear by themselves after a one-off event, but repeated alarms usually need a technician.
Likely causes:
- A one-off disturbance (for example a grid event)
- Internal component or circuit board fault
- Firmware issue
What you can safely do:
- Note the code, time and whether it clears by itself
- If your installer showed you the owner shutdown/restart procedure from the manufacturer's manual (summarised at the top of this page), you may restart the system once. Do not open covers or touch cabling.
- If the code returns or the system stays offline, call us. Internal faults are a warranty/technician job
100167boost circuit abnormalFault
What it means: The equipment's self-checks found an internal problem (for example relays, measuring circuits, internal communication or power electronics). Some of these clear by themselves after a one-off event, but repeated alarms usually need a technician.
Likely causes:
- A one-off disturbance (for example a grid event)
- Internal component or circuit board fault
- Firmware issue
What you can safely do:
- Note the code, time and whether it clears by itself
- If your installer showed you the owner shutdown/restart procedure from the manufacturer's manual (summarised at the top of this page), you may restart the system once. Do not open covers or touch cabling.
- If the code returns or the system stays offline, call us. Internal faults are a warranty/technician job
110004dc power alarmInfo
What it means: The inverter is reducing output because grid voltage is high (voltage-dependent derating required by grid rules).
Likely causes:
- High street voltage, common on sunny afternoons when many homes export solar
- Grid disturbances or voltage dips
- Long or undersized AC cabling between the inverter and the switchboard (installation issue)
- Grid protection settings that don't match your network's requirements
What you can safely do:
- No action needed if it only happens at times of high grid voltage
- If output is often limited, tell us so we can check grid voltage and settings
110005Battery stops running alarmFault
What it means: The battery has stopped running, for example because of a shutdown command or because the battery is in protection.
Likely causes:
- Cell voltage or capacity imbalance
- Over-charge or over-discharge conditions
- Internal battery hardware (relay, sensor, circuit board) fault
- Firmware or configuration mismatch between battery modules
What you can safely do:
- Check the app for other battery alarms
- Call us if it doesn't resume
110006over temperature alarmWarning
What it means: The inverter is running too hot, so it has reduced output or paused to protect itself.
Likely causes:
- High ambient temperature or direct afternoon sun on the inverter
- Blocked air vents or heat sink (dust, cobwebs, stored items)
- A fan problem (on fan-cooled models)
What you can safely do:
- Make sure nothing is stacked against or in front of the inverter, and leave the manufacturer's clearances around it
- Gently clear dust or leaves from the outside of the vents, without opening the unit or spraying water
- Let it cool. It normally resumes by itself
- If it keeps happening on mild days, call us
110014Pv over voltageFault
What it means: The DC voltage coming from the solar panels is higher than the inverter is rated for. Over-voltage can damage the inverter.
Likely causes:
- Too many panels wired in series in a string (system design/installation issue)
- Very cold, bright mornings raise panel voltage
- Incorrect panel or string configuration after a change to the system
What you can safely do:
- Do not touch the DC isolator or cables unless the manufacturer's owner shutdown tells you to
- Call us. The string design needs to be checked by a licensed installer
110021Grid Loss AlarmWarning
What it means: The inverter cannot see a normal mains supply, so it has stopped exporting to the grid (and a hybrid system may switch to backup).
Likely causes:
- Power outage in your street or area
- A tripped or switched-off solar/inverter circuit breaker in the switchboard
- Loose AC connection between the switchboard and the inverter
What you can safely do:
- Check whether the rest of the house (or your neighbours) has power, and check your network operator's outage map
- Check the switchboard for a tripped solar supply main switch or inverter breaker. Only reset it once. If it trips again, leave it off and call an electrician
- Wait. Once normal grid power is back, the inverter normally reconnects by itself after its safety checks (often a few minutes)
- If grid power is normal but the alarm stays, call us
110022Grid Volt AlarmWarning
What it means: The mains voltage the inverter measured was outside the limits allowed for your network, so it disconnected or reduced output to protect the grid. This is usually a grid condition, not a faulty inverter.
Likely causes:
- High street voltage, common on sunny afternoons when many homes export solar
- Grid disturbances or voltage dips
- Long or undersized AC cabling between the inverter and the switchboard (installation issue)
- Grid protection settings that don't match your network's requirements
What you can safely do:
- Wait. The inverter reconnects by itself once voltage is back within limits
- Note the time of day it happens. If it happens most sunny days, tell us, because it may need a voltage check or a report to your network operator
- Don't try to change grid protection settings yourself. In Australia they are set to AS/NZS 4777.2 and your network operator's requirements
110023Grid Freq AlarmWarning
What it means: Grid frequency moved outside the allowed range, so the inverter disconnected or reduced output as the standards require.
Likely causes:
- Short grid disturbance
- Running on a generator or a weak supply
- Grid settings that don't match the local network
What you can safely do:
- Wait for automatic reconnection
- If it happens often, record the times and contact us
11002410min Grid Volt AlarmWarning
What it means: The mains voltage the inverter measured was outside the limits allowed for your network, so it disconnected or reduced output to protect the grid. This is usually a grid condition, not a faulty inverter.
Likely causes:
- High street voltage, common on sunny afternoons when many homes export solar
- Grid disturbances or voltage dips
- Long or undersized AC cabling between the inverter and the switchboard (installation issue)
- Grid protection settings that don't match your network's requirements
What you can safely do:
- Wait. The inverter reconnects by itself once voltage is back within limits
- Note the time of day it happens. If it happens most sunny days, tell us, because it may need a voltage check or a report to your network operator
- Don't try to change grid protection settings yourself. In Australia they are set to AS/NZS 4777.2 and your network operator's requirements
110027LN Reverse AlarmFault
What it means: The inverter has detected an AC wiring problem, for example active and neutral swapped or a connection made the wrong way round.
Likely causes:
- AC wiring error at installation or after other electrical work
- Wiring on the meter or CT the wrong way round
What you can safely do:
- Do not touch any wiring
- Leave the system as it is and book a licensed electrician (or call us)
110029GFCI AlarmSafety-critical
What it means: The inverter measured leakage (residual) current flowing to earth above its safety limit and disconnected. This can indicate damaged insulation somewhere in the system.
Likely causes:
- Damaged DC or AC cable insulation
- Moisture in connectors or equipment
- A one-off disturbance (if it happens once and never again)
What you can safely do:
- Don't touch cabling or equipment
- If it happens repeatedly, or together with an insulation/isolation alarm, call an electrician or us promptly
110030ISO AlarmSafety-critical
What it means: The inverter measured low insulation resistance between the solar/battery DC circuits and earth. In Australia this is treated as an earth fault alarm, and the system must be checked by a licensed electrician.
Likely causes:
- Damaged DC cable insulation (for example from rodents, UV or a pinched cable)
- Water in a DC connector, isolator or junction box
- A damaged solar panel or backsheet
- Heavy dew or rain can trigger it temporarily on marginal systems
What you can safely do:
- Do not touch panels, DC cables, rooftop isolators or the inverter's DC connectors
- If it clears by itself after the weather dries out, still report it, because repeated alarms point to a developing fault
- Book an electrician or call us. An insulation test needs specialist equipment
- If you see smoke, burn marks or smell burning, keep clear and call 000
110034Fan Abnormal AlarmWarning
What it means: A cooling fan isn't working properly, which can make the unit run hot and reduce output.
Likely causes:
- Fan blocked by debris
- Fan worn or failed
- Fan wiring fault
What you can safely do:
- From outside, check that nothing is blocking the vents
- Don't open the unit
- Call us to arrange a fan check or replacement
110036FLASH ID AlarmFault
What it means: The equipment's self-checks found an internal problem (for example relays, measuring circuits, internal communication or power electronics). Some of these clear by themselves after a one-off event, but repeated alarms usually need a technician.
Likely causes:
- A one-off disturbance (for example a grid event)
- Internal component or circuit board fault
- Firmware issue
What you can safely do:
- Note the code, time and whether it clears by itself
- If your installer showed you the owner shutdown/restart procedure from the manufacturer's manual (summarised at the top of this page), you may restart the system once. Do not open covers or touch cabling.
- If the code returns or the system stays offline, call us. Internal faults are a warranty/technician job
110037ReadFlash AlarmFault
What it means: The equipment's self-checks found an internal problem (for example relays, measuring circuits, internal communication or power electronics). Some of these clear by themselves after a one-off event, but repeated alarms usually need a technician.
Likely causes:
- A one-off disturbance (for example a grid event)
- Internal component or circuit board fault
- Firmware issue
What you can safely do:
- Note the code, time and whether it clears by itself
- If your installer showed you the owner shutdown/restart procedure from the manufacturer's manual (summarised at the top of this page), you may restart the system once. Do not open covers or touch cabling.
- If the code returns or the system stays offline, call us. Internal faults are a warranty/technician job
110039Machine Type AlarmFault
What it means: There is a firmware, model or configuration mismatch between parts of the system, so it can't run normally.
Likely causes:
- Interrupted or partial firmware update
- Parts replaced with different firmware versions
- Incorrect model or country/region setting
What you can safely do:
- Don't try to reflash firmware yourself unless the manufacturer's app tells you to and it's an owner function
- Call us. We can arrange a firmware update or reconfiguration with the manufacturer
110040Inv Volt Low AlarmInfo
What it means: There isn't enough solar power or voltage for the inverter to run. This is normal at dawn, dusk and in heavy cloud.
Likely causes:
- Low sunlight (morning, evening, heavy cloud, rain)
- Shading, heavy dirt or debris on the panels
- A tripped DC isolator or string fault (if it happens in full sun)
What you can safely do:
- Check whether it only happens in low light. If so, no action is needed
- From the ground, look for shading or debris. Don't climb on the roof
- If it shows in full sun, call us
110048No Pv Input AlarmInfo
What it means: There isn't enough solar power or voltage for the inverter to run. This is normal at dawn, dusk and in heavy cloud.
Likely causes:
- Low sunlight (morning, evening, heavy cloud, rain)
- Shading, heavy dirt or debris on the panels
- A tripped DC isolator or string fault (if it happens in full sun)
What you can safely do:
- Check whether it only happens in low light. If so, no action is needed
- From the ground, look for shading or debris. Don't climb on the roof
- If it shows in full sun, call us
110049Input Power Limit AlarmInfo
What it means: Input power is being limited. Alpha ESS says this is normal in low light.
Likely causes:
- Low sunlight (morning, evening, heavy cloud, rain)
- Shading, heavy dirt or debris on the panels
- A tripped DC isolator or string fault (if it happens in full sun)
What you can safely do:
- No action needed in low light
110050Output Power Limit AlarmWarning
What it means: The inverter's output power is being limited.
Likely causes:
- A one-off disturbance (for example a grid event)
- Internal component or circuit board fault
- Firmware issue
What you can safely do:
- Note the code, time and whether it clears by itself
- If your installer showed you the owner shutdown/restart procedure from the manufacturer's manual (summarised at the top of this page), you may restart the system once. Do not open covers or touch cabling.
- If the code returns or the system stays offline, call us. Internal faults are a warranty/technician job
110059grid waveform abnormal alarmWarning
What it means: The inverter saw something abnormal about the grid supply (for example phase loss, imbalance, waveform distortion or loss of mains), so it disconnected as a safety measure.
Likely causes:
- Grid disturbance or partial outage (for example one phase lost on a 3-phase supply)
- Supply problems on the network side
- Wiring or phase-order errors at installation (if it shows up from day one)
What you can safely do:
- Check whether you have a partial power outage (some circuits or phases off)
- Wait for automatic reconnection after the grid returns to normal
- If it persists or started after electrical work, call us
SMILE-BAT-5P battery (protection codes, green LED flashing every 3 s) (8 codes)
Protection 1Temperature differenceWarning
What it means: The battery management system has reported a problem with battery voltage, current, cells or internal hardware and has limited or stopped battery operation.
Likely causes:
- Cell voltage or capacity imbalance
- Over-charge or over-discharge conditions
- Internal battery hardware (relay, sensor, circuit board) fault
- Firmware or configuration mismatch between battery modules
What you can safely do:
- This is a protection state, and the battery usually recovers automatically once conditions return to normal
- Reduce heavy loads if it relates to over-current
- If it stays in protection for more than a day, call us
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Protection 3High temperatureSafety-critical
What it means: The battery (or one of its internal parts) is above its safe temperature, so charging or discharging is limited or stopped to protect it.
Likely causes:
- High ambient temperature or direct sun on the battery
- Poor ventilation around the battery
- Heavy charge/discharge loads
- An internal battery fault
What you can safely do:
- Keep clear and do not open or touch the battery
- If you notice smoke, a burning or chemical smell, hissing, swelling or leaking, leave the area, keep others away and call 000
- Otherwise, make sure the space around the battery is clear and shaded, and call us or a licensed electrician to check it
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Protection 4Low-temperature dischargeWarning
What it means: The battery is too cold to charge or discharge safely, so it is pausing until it warms up.
Likely causes:
- Cold overnight or winter temperatures where the battery is installed
What you can safely do:
- Wait for the battery to warm up. Most systems recover automatically
- If it happens often, ask us whether the location or a heating feature (where the model has one) should be reviewed
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Protection 5Over-current chargeWarning
What it means: The battery management system has reported a problem with battery voltage, current, cells or internal hardware and has limited or stopped battery operation.
Likely causes:
- Cell voltage or capacity imbalance
- Over-charge or over-discharge conditions
- Internal battery hardware (relay, sensor, circuit board) fault
- Firmware or configuration mismatch between battery modules
What you can safely do:
- This is a protection state, and the battery usually recovers automatically once conditions return to normal
- Reduce heavy loads if it relates to over-current
- If it stays in protection for more than a day, call us
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Protection 6Over-current dischargeWarning
What it means: The battery management system has reported a problem with battery voltage, current, cells or internal hardware and has limited or stopped battery operation.
Likely causes:
- Cell voltage or capacity imbalance
- Over-charge or over-discharge conditions
- Internal battery hardware (relay, sensor, circuit board) fault
- Firmware or configuration mismatch between battery modules
What you can safely do:
- This is a protection state, and the battery usually recovers automatically once conditions return to normal
- Reduce heavy loads if it relates to over-current
- If it stays in protection for more than a day, call us
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Protection 8Cell overvoltageWarning
What it means: The battery management system has reported a problem with battery voltage, current, cells or internal hardware and has limited or stopped battery operation.
Likely causes:
- Cell voltage or capacity imbalance
- Over-charge or over-discharge conditions
- Internal battery hardware (relay, sensor, circuit board) fault
- Firmware or configuration mismatch between battery modules
What you can safely do:
- This is a protection state, and the battery usually recovers automatically once conditions return to normal
- Reduce heavy loads if it relates to over-current
- If it stays in protection for more than a day, call us
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Protection 9Cell undervoltageInfo
What it means: One or more cells are below their minimum voltage, so the battery has stopped discharging to protect itself. Alpha ESS notes a special forced-start procedure for this, which should be left to your installer.
Likely causes:
- Battery has been used down to its reserve level
- Several cloudy days with little solar to recharge
- Charging is disabled by the settings or by another fault
What you can safely do:
- Allow it to recharge from solar (or the grid, if your settings allow)
- Check the app for other alarms that could be stopping charging
- If it stays low for days in good sun, call us. Batteries left flat for long periods can be damaged
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Protection 11Low-temperature chargeWarning
What it means: The battery is too cold to charge or discharge safely, so it is pausing until it warms up.
Likely causes:
- Cold overnight or winter temperatures where the battery is installed
What you can safely do:
- Wait for the battery to warm up. Most systems recover automatically
- If it happens often, ask us whether the location or a heating feature (where the model has one) should be reviewed
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
SMILE-BAT-5P battery (error codes, red LED flashing every 3 s) (11 codes)
Error 01Hardware errorFault
What it means: The battery has reported an internal hardware error. Alpha ESS says to wait for automatic recovery and to arrange a repair if it doesn't clear.
Likely causes:
- Cell voltage or capacity imbalance
- Over-charge or over-discharge conditions
- Internal battery hardware (relay, sensor, circuit board) fault
- Firmware or configuration mismatch between battery modules
What you can safely do:
- Wait to see whether it recovers automatically
- If it doesn't, call us to arrange a repair
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Error 03Hardware errorFault
What it means: The battery has reported an internal hardware error. Alpha ESS says to wait for automatic recovery and to arrange a repair if it doesn't clear.
Likely causes:
- Cell voltage or capacity imbalance
- Over-charge or over-discharge conditions
- Internal battery hardware (relay, sensor, circuit board) fault
- Firmware or configuration mismatch between battery modules
What you can safely do:
- Wait to see whether it recovers automatically
- If it doesn't, call us to arrange a repair
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Error 05Hardware errorFault
What it means: The battery has reported an internal hardware error. Alpha ESS says to wait for automatic recovery and to arrange a repair if it doesn't clear.
Likely causes:
- Cell voltage or capacity imbalance
- Over-charge or over-discharge conditions
- Internal battery hardware (relay, sensor, circuit board) fault
- Firmware or configuration mismatch between battery modules
What you can safely do:
- Wait to see whether it recovers automatically
- If it doesn't, call us to arrange a repair
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Error 06Circuit breaker openFault
What it means: The battery's circuit breaker is open (off), so the battery is disconnected.
Likely causes:
- Breaker switched off or tripped
What you can safely do:
- Don't switch battery breakers yourself unless your installer has shown you the manufacturer's owner procedure
- Call us. A tripped breaker can indicate an underlying fault
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Error 07DIP switch differenceFault
What it means: There is a firmware, model or configuration mismatch between parts of the system, so it can't run normally.
Likely causes:
- Interrupted or partial firmware update
- Parts replaced with different firmware versions
- Incorrect model or country/region setting
What you can safely do:
- Don't try to reflash firmware yourself unless the manufacturer's app tells you to and it's an owner function
- Call us. We can arrange a firmware update or reconfiguration with the manufacturer
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Error 08LMU disconnect (slave)Fault
What it means: The inverter and battery (or parts inside the battery) have stopped talking to each other, so the battery may stop charging or discharging.
Likely causes:
- Battery switched off or in a protection state
- Loose or damaged communication cable
- Firmware or settings mismatch
What you can safely do:
- Check the battery's indicator lights and your monitoring app for other alarms
- Don't unplug or re-plug cables yourself
- Call us if it does not clear within a few hours
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Error 09Serial number missingFault
What it means: There is a firmware, model or configuration mismatch between parts of the system, so it can't run normally.
Likely causes:
- Interrupted or partial firmware update
- Parts replaced with different firmware versions
- Incorrect model or country/region setting
What you can safely do:
- Don't try to reflash firmware yourself unless the manufacturer's app tells you to and it's an owner function
- Call us. We can arrange a firmware update or reconfiguration with the manufacturer
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Error 10LMU disconnect (master)Fault
What it means: The inverter and battery (or parts inside the battery) have stopped talking to each other, so the battery may stop charging or discharging.
Likely causes:
- Battery switched off or in a protection state
- Loose or damaged communication cable
- Firmware or settings mismatch
What you can safely do:
- Check the battery's indicator lights and your monitoring app for other alarms
- Don't unplug or re-plug cables yourself
- Call us if it does not clear within a few hours
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Error 11Software version inconsistentFault
What it means: There is a firmware, model or configuration mismatch between parts of the system, so it can't run normally.
Likely causes:
- Interrupted or partial firmware update
- Parts replaced with different firmware versions
- Incorrect model or country/region setting
What you can safely do:
- Don't try to reflash firmware yourself unless the manufacturer's app tells you to and it's an owner function
- Call us. We can arrange a firmware update or reconfiguration with the manufacturer
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Error 12Multi masterFault
What it means: There is a firmware, model or configuration mismatch between parts of the system, so it can't run normally.
Likely causes:
- Interrupted or partial firmware update
- Parts replaced with different firmware versions
- Incorrect model or country/region setting
What you can safely do:
- Don't try to reflash firmware yourself unless the manufacturer's app tells you to and it's an owner function
- Call us. We can arrange a firmware update or reconfiguration with the manufacturer
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Error 13MOS over-temperatureSafety-critical
What it means: The battery's switching transistors (MOS) are too hot. Alpha ESS lets the battery cool for 30–40 minutes before restarting.
Likely causes:
- High ambient temperature or direct sun on the battery
- Poor ventilation around the battery
- Heavy charge/discharge loads
- An internal battery fault
What you can safely do:
- Keep clear and do not open or touch the battery
- If you notice smoke, a burning or chemical smell, hissing, swelling or leaking, leave the area, keep others away and call 000
- Otherwise, make sure the space around the battery is clear and shaded, and call us or a licensed electrician to check it
Source: AlphaESS SMILE-BAT-5P Installation Manual (2022-11-18), section 4 Error and Protection Code
Manufacturer support contacts
| Contact | Phone | Email / channel |
|---|---|---|
| Alpha ESS Australia (website) | 1300 968 933 | australia@alpha-ess.com |
If Total Solar installed your system, contact us first.
Need help with a fault code?
Book a service call with our licensed electricians, or call us to talk it through. Have your fault code and a photo of the screen or app ready.