Battery Charger - Victron energy EasySolar-II 48/3000/35-32 230V MPPT 250/70 GX Manuel

4.2 Features specific on-grid and off-grid systems combined with PV
4.2.1 External current transformer (optional)
When used in a grid-parallel topology the internal current transformer cannot measure the current to or from the mains.
In this case an external current transformer has to be used. See appendix A. Contact your Victron Distributor for further
information about this installation type.
4.2.2 Frequency shift
When solar inverters are connected to the AC-output of the product, excess solar energy is used to recharge the
batteries. Once the absorption voltage is reached, charge current will reduce and excess energy will be fed back into the
mains. If the mains is not available, the product will slightly increase the AC frequency to reduce the output of the solar
inverter.
4.2.3 Built-in Battery Monitor
The ideal solution when the product is part of a hybrid system (diesel generator, inverter/chargers, storage battery, and
alternative energy). The built-in battery monitor can be set to start and stop the generator:
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Start at a preset % discharge level, and/or
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start (with a preset delay) at a preset battery voltage, and/or
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start (with a preset delay) at a preset load level.
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Stop at a preset battery voltage, or
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stop (with a preset delay) after the bulk charge phase has been completed, and/or
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stop (with a preset delay) at a preset load level.
4.2.4 Autonomous operation when the grid fails
Houses or buildings with solar panels or a combined micro-scale heating and power plant or other sustainable energy
sources have a potential autonomous energy supply which can be used for powering essential equipment (central
heating pumps, refrigerators, deep freeze units, Internet connections, etc.) during a power failure. A problem is however
that grid connected sustainable energy sources drop out as soon as the grid fails. With the product and batteries, this
problem can be solved: the product can replace the grid during a power failure. When the sustainable energy
sources produce more power than needed, the product will use the surplus to charge the batteries; in the event of a
shortfall, the product will supply additional power from the battery

4.3 Battery charger

4.3.1 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.
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