- Solar and energy
- Solar inverter
Err 33
Victron Err 33 on a SmartSolar charge controller: PV overvoltage
Risk level
High
Professional inspection is recommended.
Urgency
High
Quick answer
The panel voltage went above the maximum the SmartSolar charge controller accepts, so it stopped charging. It resets itself once the voltage drops. Note the time and temperature and check the day's maximum PV voltage in VictronConnect.
Safety first
Stop and check this first
- Do not unplug panel connectors or controller cables yourself: panels deliver dangerous DC voltage in daylight and disconnecting under current can cause an arc.
- Victron states that damage from excessive PV voltage is not covered by warranty. If Err 33 repeats, ask for the PV array to be reviewed without delay.
Safe checks you can perform
- Code and LEDs on the controller
- Maximum PV voltage in the history
- Time and temperature when it appears
- Automatic reset when the voltage drops
- Open circuit voltage of the PV array
Leave these tasks to a qualified professional
- Do not attempt this professional task: Voc per string against the controller maximum
- Do not attempt this professional task: Rearranging panels if there is no margin
- Do not attempt this professional task: Controller check after overvoltage events
What a technician must be able to justify
Technician visit
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Voc per string against the controller maximum
What they doThe installer measures each string's open circuit voltage with a multimeter and works out cold weather Voc from the panels' temperature coefficient.
They must show youthe measured Voc, the temperature at the time and the controller maximum.
In writingthe calculation with the 10 % margin and the number of panels per string.
Rearranging panels if there is no margin
What they doIf cold weather Voc leaves no margin, the installer changes how panels are arranged in series, as Victron indicates for this error.
They must show youthe new configuration and the Voc measured afterwards.
In writingold and new configuration and the date of the change.
Controller check after overvoltage events
What they doThe installer reviews the Vmax and overvoltage warning history and checks that the controller charges normally again.
They must show youthe history and normal charging after the fix.
In writingthe test result and, if the controller is replaced, the reason.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Follow these steps
Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
Code and LEDs on the controller
- Who:
- you, no tools.
- How:
- check the code in VictronConnect, the remote display or the GX device and see whether the absorption and float LEDs are blinking rapidly.
- Result that matters:
- the manual links Err 33 to that rapid blinking and to charging stopping.
- If code and blinking match:
- it is PV overvoltage; do not touch panel cables or connectors.
- If the code is different:
- look up that code, because the cause changes.
- Evidence to keep:
- screenshot of the code and a short video of the LEDs.
Evidence: MPPT Solar Charger Error Codes · MPPT solar charger manual SmartSolar MPPT 150/35 & 150/45 Rev 12 - 06/2026
Maximum PV voltage in the history
- Who:
- you, from the app.
- How:
- in the VictronConnect, display or GX device history, look at the highest PV voltage each day (Vmax) and earlier overvoltage warnings.
- Result that matters:
- whether Vmax reaches the rated maximum shown in the model name.
- If Vmax reaches the maximum on several days:
- the PV array is at the limit and the installer must review it.
- If Vmax stays clearly below:
- tell the installer, as it does not fit a repeated overvoltage.
- Evidence to keep:
- history screenshots with Vmax per day.
Evidence: MPPT solar charger manual SmartSolar MPPT 150/35 & 150/45 Rev 12 - 06/2026
Time and temperature when it appears
- Who:
- you, no tools.
- How:
- note the time, whether it was sunny and the outdoor temperature each time Err 33 appears.
- Result that matters:
- whether it matches cold, sunny mornings, when panel Voc is higher.
- If it appears in cold sun:
- it points to a lack of design margin for cold.
- If it also appears in hot weather:
- the configuration is even closer to the limit; tell the installer as soon as possible.
- Evidence to keep:
- list of dates, times and temperatures.
Evidence: MPPT solar charger manual SmartSolar MPPT 150/35 & 150/45 Rev 12 - 06/2026
Automatic reset when the voltage drops
- Who:
- you, no tools.
- How:
- do not disconnect the panels or the controller; wait for the PV voltage to drop and check in the app whether charging resumes.
- Result that matters:
- Victron says the error clears itself once the PV voltage has dropped to a safe limit.
- If charging resumes:
- the controller still works, but the error will return with the same PV array.
- If it does not resume once the voltage is low:
- there may be damage and the installer assesses it.
- Evidence to keep:
- time of the reset or of the failure to reset.
Evidence: MPPT Solar Charger Error Codes · MPPT solar charger manual SmartSolar MPPT 150/35 & 150/45 Rev 12 - 06/2026
Open circuit voltage of the PV array
- Who:
- qualified PV installer.
- How:
- measure the open circuit voltage of each panel string and compare it with the controller maximum, taking the panels' temperature coefficient into account.
- Result that matters:
- the expected cold weather Voc stays below the maximum with the 10 % margin Victron recommends.
- If it leaves no such margin:
- the panels must be rearranged.
- If it leaves margin:
- the installer reviews the history and configuration with the distributor.
- Evidence to keep:
- table with measured Voc per string, temperature at the time and the controller maximum.
Panels produce DC voltage whenever they get light. Victron says voltages above 50 V are generally considered dangerous and only a qualified technician should handle them.
Evidence: MPPT solar charger manual SmartSolar MPPT 150/35 & 150/45 Rev 12 - 06/2026
Still not solved
If the error persists, stop here. See what the technician must do and show you.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- Solar and energy
- Brand
- Victron Energy
- Product type
- Solar inverter
Known code variants
- SmartSolar error 33
- Victron Err 33
- Victron error 33
- Victron MPPT PV over voltage
- Victron MPPT sobretensión FV
What it means
The controller monitors the solar panel (PV) input voltage against its rated maximum, shown in the model name and on the type plate. If it is exceeded, charging stops and only resumes once the voltage drops 5 V below that maximum. Victron says the PV array configuration with regard to open circuit voltage (Voc) is critical for that controller. Voc rises below 25 °C, so panels in series, their temperature coefficient and cold weather all matter. The code does not say by how much the limit was exceeded or whether damage has occurred.
Warnings and stop conditions
- Higheditorial warning
Do not unplug panel connectors or controller cables yourself: panels deliver dangerous DC voltage in daylight and disconnecting under current can cause an arc.
Evidence: MPPT solar charger manual SmartSolar MPPT 150/35 & 150/45 Rev 12 - 06/2026
- Highsource verified
Victron states that damage from excessive PV voltage is not covered by warranty. If Err 33 repeats, ask for the PV array to be reviewed without delay.
Evidence: MPPT solar charger manual SmartSolar MPPT 150/35 & 150/45 Rev 12 - 06/2026
Symptoms and causes
Probable causes · in order
- Too many panels in series for this controllerPossible
If the combined Voc of the panels in series sits at the controller's maximum, the error appears in strong sun. This is what Victron points to: the PV array configuration is critical for that model.
Evidence: MPPT Solar Charger Error Codes · MPPT solar charger manual SmartSolar MPPT 150/35 & 150/45 Rev 12 - 06/2026
- Cold raising Voc with no design marginPossible
Voc is higher below 25 °C. If Err 33 shows mostly on cold, sunny mornings, the design left no margin for cold; Victron recommends an extra 10 %.
Evidence: MPPT solar charger manual SmartSolar MPPT 150/35 & 150/45 Rev 12 - 06/2026
Virtual technician
Does Err 33 still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
MPPT Solar Charger Error Codes
Victron Energy · 2026 · official_doc
- 2
MPPT solar charger manual SmartSolar MPPT 150/35 & 150/45 Rev 12 - 06/2026
Victron Energy · 2026 · manual
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