If you are dipping your feet into the solarwaters you may be overwhelmed by the number of components which make up a solarPV system and be unsure of how to choose those specific components to put togetherthe best system for your home and your specific needs. Because a solar charge controller enables you to monitor battery charging, thus avoiding over orunder-charging, then if you are planning an on-grid system, you won't need acontroller.
If you are contemplating on off-grid systemusing batteries, are planning to use solar and wind power in the same system,or are merely planning a backup power source for outages-which requiresbatteries-then you will need to choose a good charge controller for your system.
Solar panels and wind generators bothproduce electricity, however those outputs vary significantly depending on theavailable sun or the wind speed. Because of this variability, the output mustbe converted to something which is a little more consistent, which is whereyour controller comes in. Whether your batteries are sealed or gel, yourcontroller will make sure they are charged in a consistent manner.
If you are using a wind generator, thecharge controller is probably either built into the unit, or comes as part ofthe package, so you won't need to choose one separately, however if you areonly using solar panels to power your home, then you need to know how to selectthe best charge controller.