MultiPlus

This manual applies to the following inverter/charger models:

Multifunctional

The Multi gets its name from the multiple functions it can perform. It is a powerful true sine wave inverter, a sophisticated battery charger that features adaptive charge technology and a high-speed AC transfer switch in a single enclosure. Besides these primary functions, however, the Multi has several advanced features that provide a range of new applications, as outlined below.

Uninterrupted AC power

In the event of a grid failure or shore or generator power being disconnected, the inverter within the Multi is automatically activated and takes over the supply to the connected loads. This happens so fast (less than 20 milliseconds) that computers and other electronic equipment will continue to operate without disruption.

Parallel and 3-phase operation capability

Up to 6 inverters can operate in parallel to achieve higher power output. Operation in a 3-phase configuration is also possible.

PowerControl – Dealing with a limited generator or shoreside power

With a Digital Multi Control panel a maximum generator or shore current can be set. The Multi will then take account of other AC loads and use whatever is extra for charging, thus preventing the generator or shore supply from being overloaded.

Programmable relay

The Multi is equipped with a programmable relay that, by default, is set as an alarm relay. The relay can be programmed for all kinds of other applications, however, for example, as a starter relay for a generator.

Adaptive 4-stage charging characteristics: bulk – absorption – float – storage

The microprocessor-driven adaptive battery management system can be adjusted for various types of batteries. The adaptive function automatically adapts the charging process to battery use.

The right amount of charge: variable absorption time

In the event of slight battery discharge, absorption is kept short to prevent overcharging and excessive gas formation. After deep discharging, the absorption time is automatically extended in order to fully charge the battery.

Preventing damage due to excessive gassing: The BatterySafe mode

If, in order to quickly charge a battery, a high charge current in combination with a high absorption voltage has been chosen, damage due to excessive gassing will be prevented by automatically limiting the rate of voltage increase once the gassing voltage has been reached.

Less maintenance and ageing when the battery is not in use: The storage mode

The Storage mode kicks in whenever the battery has not been subjected to discharge for 24 hours. In the Storage mode, float voltage is reduced to 2.2V/cell (13.2V for 12V battery) to minimise gassing and corrosion of the positive plates. Once a week, the voltage is raised back to the absorption level to “equalise’ the battery. This feature prevents stratification of the electrolyte and sulphation, a major cause of early battery failure.

Two DC outputs for charging two batteries

The main DC terminal can supply the full output current. The second output, intended for charging a starter battery, is limited to 1 A and has a slightly lower output voltage.

Increasing service life of the battery: temperature compensation

The temperature sensor (supplied with the product) serves to reduce charging voltage when the battery temperature rises. This is particularly important for maintenance-free batteries, which could otherwise dry out by overcharging.

More on batteries and charging

Our book “Energy Unlimited’ offers further information on batteries and battery charging and is available free of charge on our website (see https://www.victronenergy.com/support-and-downloads/technical-information). For more information on adaptive charging, please also refer to the Technical Information section on our website.

Self consumption – solar energy storage systems

When the Multi is used in a configuration in which it will feed back energy to the grid, it is required to enable grid code compliance by selecting the grid code country setting with the VEConfigure tool. Once set, a password will be required to disable grid code compliance or change grid code related parameters. If the local grid code is not supported by the Multi, an external certified interface device should be used to connect the Multi to the grid