Solar Charge Controller is an electronic device used to regulate the direct current into the battery charged and taken from the battery to the load.
Solar charge controller set overcharging (extra charge - because the batteries are 'full') and the excess voltage from the solar cells. Excess voltage and charging will reduce battery life.
Solar charge controller to apply the technology Pulse width modulation (PWM) to regulate the charging function and the release of flows from the battery to the load.
Solar cell 12 Volt generally have a output voltage 16-21 Volt.
So without solar charge controllers, batteries will be damaged by over-charging and voltage instability.
General in-charge battery voltage of 14 - 14.7 Volt.
Some functions of the detail of the solar charge controller is as follows:
* Set the current for charging the battery, avoid overcharging, and transient overvoltage.
* Manage the flow of the released / taken from the battery so the battery is not 'full discharge', and overloading.
* Monitoring the battery temperature
To buy a solar charge controller that must be considered are:
* Voltage 12 Volt DC / 24 Volt DC
* The ability (in direct current) from the controller. For example 5 Ampere, 10 Ampere, etc..
* Full charge and low voltage cut
As already mentioned above solar charge controllers which usually have the ability detect whether the battery battery capacity. When the battery is fully charged, automatically charging current from the solar cell stops. Detection mode is through the monitor battery voltage level. Solar charge controller will charge the battery until a certain voltage level, then if the voltage drop, then the battery will be recharged.
Solar Charge Controller usually consists of: an input (two terminals) connected to the output of solar cell, one output (two terminals) connected to the battery / batteries and one output (two terminals) connected to the load (load). DC current from the battery can not be entered into solar cell because there is usually a 'diode protection' that just passing DC current from solar cell to the battery, not vice versa.
Charge Controller and some even have more than one resource, that is not only coming from the sun, but also can come from wind power or micro-hydro. In the market has found many charge controllers 'tandem' which has two inputs originating from the sun and wind. To this energy produced more than doubled since the wind can blow at any time, so the limited time that can not be supplied on a full solar energy, can be supported by wind power. If the average wind speed is realized then the power of electricity per month can be much larger than the sun's energy.
Solar Charge Controller Technology
There are two types of technology commonly used by the solar charge controller: pwm solar charge controller
* PWM (Pulse Wide Modulation), as the name using 'wide' pulse of electrical on and off, thereby creating as if the electrical sine wave form.
* MPPT (max Power Point Tracker), a more efficient conversion of DC to DC (Direct Current). MPPT can take power from the PV max. MPPT charge controllers can store excess power not used by the load to the battery, and if the required load power is greater than the power generated by PV, then the power can be drawn from the battery.
Excess MPPT in this illustration : solar cell sizes 120th Watt, has a characteristic max 17.1 Volt Power Voltage and Current Power max 7:02 Amperes. In addition to MPPT solar charge controller and battery voltage of 4.12 volts, the mean power produced is 4.12 Volts x Amperes = 87.05 Watt 7:02. With MPPT, the Ampere that can be given is about 120W: 12.4 of V = 9.68 Amperes.
The technology is rarely used, but very cheap, is Type 1 or 2 Stage Control, with relay or transistor. Relay function is to short or to disconnect the battery from the solar cell.