The most important solar charge controller is to properly control the charge and discharge, protect battery and solar panel to give them as long a life as possible.
There are two types of solar charge controllers in the market: Pulse width modulation (PWM) and maximum power point tracking (MPPT)
The PWM is low cost but not as efficient as the MPPT. The MPPT can give you up to 30% more power than PWM, it also allows the strings of panels to be connected in series for higher voltages, keeping the amperage lower and the wire size smaller, especially for long-wire runs to the PV array.
To choose a suitable solar charge controller, we have to know some information, like The wattage of the solar panel; the voltage of the battery, then we could calculate the amps of the solar controller.
For example 100 watt solar panel/12 volt battery=8.3 amps. Then 10A charge controller is ok for you, if use 200w solar panel and 12v battery, you must go to 20A charge controller.
The solar parking lot light manufacture will choose a suitable charge controller, some controllers build inside the light housing. You could check it with your supplier.
