The AVA analogical charge controller performs the following functions in a photovoltaic installation:
- Prevents the battery from discharging through the module circuit (this could damage the modules) using a low voltage drop blocking diode between the module and the battery.
- Limits the battery charge when the voltage reaches a maximum value (14.7 V in the 12V model and 28.8 V in the 24 V model), at which point it switches to the floating position, in which it allows a minimum charging current to compensate the battery self-discharge. High charges that could increase the voltage could lead to electrolyte evaporation and battery damage. The green indicator light (BAT CARGADA) on the front panel of the charge controller shows when the full state of charge has been reached.
- Prevents overdischarge of the battery by disconnecting the load when the voltage drops below approximately 10.8 or 21.6 V (for the 12 or 24 V models respectively). Continuing the consumption below these values could cause accumulative and irreversible damage to the battery. The red light (BATERIA BAJA) indicates that the load has been disconnected from the battery.
- Measurement of the PV module charge using the incorporated ampmeter, which at any given time shows the operational characteristics of the PV module. The current registered current will be at its minimum when the battery is charged.
- Battery voltage measurement.
The voltmeter shows the instantaneous battery voltage, which gives an idea
of the state of charge of the battery.
The following elements of the installation should be connected to the charge controller connectors, respecting at all times the indicated polarities:
- Photovoltaic modules: the positive and negative cables from the PV modules should be connected to terminals 1 and 2, respectively.
- Battery: the battery cables will be connected to terminals 7 (negative) and 8 (positive). Cables of a sufficiently large cross-sectional area should be used so as to avoid voltage drops of more than 4%.
- Terminal 5 is an output for a optional second battery or to connect a load of less than 10A of current intensity. This load should be able to withstand the high voltage variations that the PV module produces as a function of the current.
On the front panel of the charge controller there is a dual position manual switch "CARGA DIRECTA" (DIRECT CHARGE) and "CARGA REGULADA" (REGULATED CHARGE). Initially it should be in the REGULATED CHARGE position. If, due to any cause, the charge controller does not operate correctly and does not transfer charge to the battery, or the battery has a very low state of charge, then this switch can be put in the "DIRECT CHARGE" position, in which the current flows directly from the PV modules to the battery (trough the diode).
Note: the voltages indicated
are those used for Tudor batteries and they may vary for other batteries.
When acquiring a charge controller, the battery manufacturer and model
to be used should be specified.