3. Operation
3.1. On/Off/Charger Only Switch
When switched to ‘on’, the inverter/charger is fully functional. The inverter will come into operation, and the LED ‘inverter on’ will light up.
An AC voltage connected to the ‘AC in’ terminal will be switched through to the ‘AC out’ terminal, if within specifications. The inverter will switch off, the ‘mains on’ LED will light up, and the charger commences charging. The ‘bulk’, ‘absorption’ or ‘float’ LEDs will light up, depending on the charger mode.
If the voltage at the ‘AC-in’ terminal is rejected, the inverter will switch on.
When the switch is switched to ‘charger only’, only the battery charger of the inverter/charger will operate (if mains voltage is present). The input voltage is also switched through to the ‘AC out’ terminal in this mode.
NOTE: When only the charger function is required, ensure that the switch is switched to ‘charger only’. This prevents the inverter from being switched on if the mains voltage is lost, thus preventing your batteries from running flat.
3.2. Remote control
The inverter/charger can be remotely turned on, off or set to charger-only mode, via a switch or a Digital Multi Control panel.
The Digital Multi Control panel has a simple rotary knob with which the maximum current of the L1 AC input can be set. This does not affect the L2 AC input: see PowerControl section in the "other features" chapter.
3.3. Equalisation and forced absorption
3.3.1. Equalisation
Traction batteries require regular additional charging. In the equalisation mode, the inverter/charger will charge with increased voltage for one hour (1V above the absorption voltage for a 12V battery, 2V for a 24V battery and 4V for a 48V battery). The charging current is then limited to 1/4 of the set value.
When equalisation mode is activated, the ‘bulk’ and ‘absorption’ LEDs flash intermittently.
Warning
Equalisation mode supplies a higher charging voltage than most DC-consuming devices can cope with. These devices must be disconnected before additional charging takes place.
3.3.2. Forced absorption
Under certain circumstances, it can be desirable to charge the battery for a fixed time at the absorption voltage level. In Forced Absorption mode, the MultiPlus-II will charge at the normal absorption voltage level during the set maximum absorption time.
When Forced Absorption mode is active, the ‘absorption’ LED is illuminated.
3.3.3. Activating equalisation or forced absorption
The inverter/charger can be put into both these states from the remote panel as well as with the front panel switch, provided that all switches (front, remote, and panel) are set to ‘on’ and no switches are set to ‘charger only’.
The procedure below should be followed to put the inverter/charger in this state.
If the switch is not in the required position after following this procedure, it can be switched over quickly once. This will not change the charging state.
Note
Switching from ‘on’ to ‘charger only’ and back, as described below, must be done quickly. The switch must be toggled such that the intermediate position is 'skipped', as it were. If the switch remains in the ‘off’ position even for a short time, the device may be turned off. In that case, the procedure must be restarted at step 1. A certain degree of familiarisation is required when using the front switch on the Compact in particular. When using the remote panel, this is less critical.
Procedure:
Check whether all switches (i.e. front switch, remote switch or remote panel switch if present) are in the ‘on’ position.
Activating equalisation or forced absorption is only meaningful if the normal charging cycle is completed (charger is in 'Float').
To activate:
Switch rapidly from ‘on’ to ‘charger only’ and leave the switch in this position for ½ to 2 seconds.
Switch rapidly back from ‘charger only’ to ‘on’ and leave the switch in this position for ½ to 2 seconds.
Switch once more rapidly from ‘on’ to ‘charger only’ and leave the switch in this position.
On the inverter/charger (and, if connected, on the MultiControl panel), the three LEDs ‘Bulk’, ‘Absorption’ and ‘Float’ will now flash 5 times.
Subsequently, the LEDs ‘Bulk’, ‘Absorption’ and ‘Float’ will each light for 2 seconds.
If the switch is set to ‘on’ while the ‘Bulk’ LED lights, the charger will switch to equalisation.
If the switch is set to ‘on’ while the ‘Absorption’ LED lights, the charger will switch to forced absorption.
If the switch is set to ‘on’ after the three LED sequences have finished, the charger will switch to ‘Float’.
If the switch has not been moved, the MultiPlus-II will remain in ‘charger only’ mode and switch to ‘Float’.
3.4. LED Indications
| LEDs off | |
| LEDs blinking | |
| LEDs illuminated |
| Inverting The inverter is on. Inverter power is supplied to the load. The "inverter" LED is on. |
| Overload pre-alarm The nominal output of the inverter is exceeded. The "overload" LED is blinking |
| Overload alarm The inverter is switched off due to overload or short circuit. The "overload" LED is on. |
| Low battery pre-alarm The battery voltage is getting low. The battery is almost fully exhausted. The "low battery"LED is blinking. |
| Low battery alarm The inverter has switched off due to low battery voltage. The "low battery" LED is blinking. |
| Temperature pre-alarm The internal temperature is reaching a critical level. The "temperature" LED is blinking. |
| Temperature alarm The inverter has switched off due it's internal temperature being too high. The "temperature" LED is on. |
| Overload pre-alarm and low battery pre-alarm The battery is nearly exhausted and the nominal output of the inverter is exceeded. The "overload" and "low battery" LEDs are both blinking alternately, |
| Ripple pre-alarm The ripple voltage on the battery terminals is too high. The "overload" and "low battery" LEDs are both blinking simultaneously. |
| Ripple alarm The inverter has switched off due to excess ripple voltage on the battery terminals. The "overload" and "low battery" LEDs are both on. |
| Bulk charging The AC input voltage is switched through and the charger operates in bulk mode. The "bulk" LED is on. |
| BatterySafe The mains voltage is switched through and the charger is on. However, the set absorption voltage has not yet been reached. The "bulk" and "absorption" LEDs are both on. |
| Absorption charging The mains voltage is switched through and the charger operates in absorption mode. The "absorption" LED is on. |
| Float charging The mains voltage is switched through and the charger operates in float mode. The "float" LED is on. |
| Equalize charging The mains voltage is switched through and the charger operates in equalize mode. The "bulk" and "absorption" LED are both blinking. |
| PowerControl The AC input is switched through. The AC output current is equal to the preset maximum input current. The charge current is reduced to 0A. The "mains on" LED is blinking. |
| PowerAssist The AC input is switched through, but the load requires more current than the preset maximum input current. The inverter is switched on to supply the required additional current. The "mains on" LED is on and the "inverter" LED is blinking. |
For more error codes, see the Error Indications chapter.
For the latest and most up-to-date information about the blink codes, please refer to the Victron Toolkit app. Scan the QR code or click on the link to go to the Victron Support and Downloads/Software page: https://www.victronenergy.com/support-and-downloads/software#victron-toolkit-app |  |
3.5. Shut down procedure
To switch the inverter/charger off, use the on/off/charger-only only switch located on the bottom left-hand underside of the case. The middle position of the switch is the OFF position.
To completely de-power the inverter/charger, disconnect the DC fuse or turn off the isolation switch, DC contactor or DC circuit breaker, located between the battery and the DC terminals of the unit. Note that dangerous residual voltages may still exist inside the product and at its terminals after shutdown. Never open the product casing, or touch bare terminals.
3.6. Maintenance
The inverter/charger does not require specific maintenance. It will suffice to check all connections once a year. Avoid moisture and oil/soot/vapours, and keep the device clean.