Battery Charger; Lead-Acid Batteries - Victron energy MultiPlus-II 12/3000/120-32 Manuel

2.3 Battery charger

2.3.1 Lead-acid batteries

Adaptive 4-stage charge algorithm: 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 2,2 V/cell (13,2 V for 12 V 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.
Battery voltage sense: the correct charge voltage
Voltage loss due to cable resistance can be compensated by using the voltage sense facility to measure voltage directly on the DC bus
or on the battery terminals.
Battery voltage and temperature compensation
The temperature sensor (supplied with the product) serves to reduce charging voltage when battery temperature rises. This is
particularly important for maintenance-free batteries, which could otherwise dry out by overcharging.
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 4 A and
has a slightly lower output voltage (12 V and 24 V models only).
2.3.2 Li-ion batteries
Victron LiFePO Smart batteries
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Use the VE.Bus BMS
2.3.3 Other Li-ion batteries
Please see https://www.victronenergy.com/live/battery_compatibility:start
2.3.4 More on batteries and battery charging
Our book 'Energy Unlimited' offers further information on batteries and battery charging, and is available free of charge on our website
(see www.victronenergy.com  Support & Downloads  General Technical Information). For more information on adaptive charging,
please also refer to the General Technical Information on our website.
2.4 ESS – Energy Storage Systems: feeding energy back into the grid (not applicable to the
MultiPlus-II 12/3000/120-32)
When the MultiPlus-II is used in a configuration in which it will feed back energy into the grid it is required to enable grid code
compliance by selecting the appropriate 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.
Depending on the grid code there are several reactive Power control modes:
Fixed cos φ
•
Cos φ as function of P
•
• Fixed Q
• Q as function of input voltage
Reactive Power capability
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