Charge controllers come in various types. Solar charge controllers regulate the charge from a solar panel array to a battery bank.
A solar charge controller will protect your batteries frombeing overcharged by your solar panels and it will block any reverse current (from the batteries) as well. Temperature sensors are an inexpensive addition that help the charge controller more accurately regulate the charge of the battery bank
Youll notice that solar charge controllers are specified by both amperage and voltage. You will need a charge controller that matches the voltage of your solar panel array and battery bank. (Usually 12, 24 or 48 VDC) And youll want to make sure the solar panel charge controller has enough capacity to handle the current (in amps) from your solar panel array.
A charge controller or charge regulator is basically a voltage and/or currentregulator to keep batteries safe from overcharging. It regulates the voltage and current coming from the solar panels going to the battery and provide regulated power that is compatiable to the batteries or Dc utilities.