How To Select Charge Controller


Charge Controllers

Solar Charge Controller is one of the main component in the solar power system. It regulates the energy power from solar panels from overcharging/discharging to your battery bank or utility grid. It also helps to prevent an overload or short circuit to your power system; or even to prevent the battery bank from reverse charging back the solar panels, so that it can ensure to keep your batteries to perform at their optimal level.
Generally Solar Charge Controllers can be found in 12v or 24v setting for all battery bank system and it all depends on how you design or plan for your power system.

There are 2 types of solar charge controller in the market :

1. PWM


PWM (Pulse-Width Modulation) controller more economical if compare to MPPT controller. It is ideal for small size of solar power system. It has 3 stage charge cycle – Bulk, Absorption , Float charge to optimize the battery bank from overcharging / discharging. However, it creates large power loses and it is not recommend to be used for a large power system.

Click Here for PWM series Solar Controller


MPPT (Maximum Power Point Tracking) controller are different than the traditional PWM controller which it can optimize more output voltage power as 30% from the solar panels, so that the maximum amount of energy is transferred to the battery bank. This significant digital MPPT controller apply very well in any big solar power system due to it can fluctuate and adjust in any factors such like temperature and light intensity .

Click Here for MPPT series Solar Controller


PWN compare to MPPT performance :
PWM controller : 12.4v
Solar Panel : 200w /16.5v = 12A
12.4v x 12A = 150w
LOST of 25% of energy

MPPT can match the output of the solar panels to the battery voltage as to ensure the maximum charge in AMPs
MPPT: 12.4v x 16A = 200W
MPPT controller able to maintain the full energy of 200W solar panel by compensate the lower battery voltage 12.4v and deliver 16Amps to the system .


How to determine the size of your solar charge controller

You can always look the watts and amps that produce by the solar panels or array in order to determine what size of your solar charge Controller . For example:
Solar Array : 500w
Battery bank : 24v
Calculation : 500w/ 24v = 20.83 amps.

For a safety factor, it is recommended to multiply a safety factor value at 1.25 (25%) to protect the controller inputs : 20.83 x 1.25= 26.04amps

In this case, you would need 30 amp controller. The SAIP SML controller would fit to your requirements.