Battery Charger; Lead-Acid Batteries; Ess - Energy Storage Systems: Feeding Energy Back Into The Grid - Victron energy MultiPlus-II 24/3000/70-32 Manual De Instrucciones

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 2,2V/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.
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 4A and
has a slightly lower output voltage (12V and 24V models only).
2.3.2 Li-ion batteries
Victron LiFePO4 Smart batteries
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
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.
If the local grid code is not supported by the MultiPlus-II an external certified interface device should be used to connect the MultiPlus-II
to the grid.
The MultiPlus-II can also be used as a bidirectional inverter operating parallel to the grid, integrated into a customer designed system
(PLC or other) that takes care of the control-loop and grid measurement,
Special note regarding NRS-097 (South Africa)
1. The maximum allowed impedance of the network is 0.28Ω + j0.18Ω
2. The inverter is fulfilling the unbalance requirement in case of multiple single phase units only when the Color Control GX is
part of the installation.
Special notes regarding AS 4777.2 (Australia/New Zealand)
1. IEC62109.1 certification and CEC approval for off-grid use does NOT imply approval for grid-interactive installations.
Additional certification to IEC 62109.2 and AS 4777.2.2015 are required before grid-interactive systems can be implemented.
Please check the Clean Energy Council website for current approvals.
2. DRM – Demand Response Mode
When the AS4777.2 grid code has been selected in VEconfigure, DRM 0 functionality is available on port AUX1 (see
appendix A.
To enable grid connection, a resistance of between 5kOhm and 16kOhm must be present between the terminals of port AUX1
(marked + and - ). The MultiPlus-II will disconnect from the grid in case of an open circuit or a short circuit between the
terminals of port AUX1. The maximum voltage that may be present between the terminals of port AUX1 is 5V.
Alternatively, if DRM 0 is not required, this functionality can be disabled with VEConfigure.
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