Victron energy Multi 500VA 12/500/20 Manuel page 4

2. DESCRIPTION
2.1 General
Multi-functional
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. Beside 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 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.
PowerControl – Dealing with limited generator or shore side power
With a 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.
2.2 Battery charger
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 aging when the battery is not in use: the Storage mode
The Storage mode kicks in whenever the battery has not been subjected to discharge during
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 'equalize' the battery. This feature prevents stratification of the
electrolyte and sulphation, a major cause of early battery failure.
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