Solar Charge Controllers The strong the sunlight, the more voltage solar panels produce. In this case, extremely excessive voltage may damage your solar PV batteries. This is primarily the reason why a Solar Charge Controller is used; that is to keep the right charging voltage on solar PV batteries. Solar charge controllers basically prevents your solar PV batteries from overcharging. It also helps prolong its life as it regulates the charge to the batteries.
Stages of Solar Charge Controllers
Most modern solar charge controllers goes through a 3-stage charge cycle as follow:
- 1st Stage: Bulk – while solar PV batteries extract maximum current, voltage slowly rises to bulk level (up to 14.6volts); and when it reached its level, 2nd stage begins.
- 2nd Stage: Absorption – in this stage, voltage is kept at a bulk level usually for about an hour while current slowly decreases as the battery’s charging.
- 3rd Stage: Float – after the absorption time, voltage is now lowered to a float level (up to 13.7volts) while the battery’s drawing a small maintenance current that’ll be enough until the next charging cycle.
Types of Solar Charge Controllers
- MPPT (Maximum Power Point Tracking) – reduces battery’s charge time, turning extra voltage into amperage.
- PWM (Pulse Width Modulation) – slowly reduces battery’s power supply w/o overcharging, thus, reducing stress to the battery.
Features of Solar Charge Controllers
- Battery system monitor
- Automatic voltage selection
- On/Off battery charging
- Field adjustment parameters
- Temperature compensation
- Lighting protection
- LED digital indicator light