Most 12 volt panels put out about 16 to 20 volts so if there is no regulation the batteries will be damaged from overcharging.
Do i need a charge controller for solar panel.
In general you do not require a charge controller that usually requires the minimum maintenance or drop charge panels including but never limited to the one to five watt panels.
If the quotient is above 200 you don t need a controller.
There are always caveats to everything however.
You don t need a charge controller with small 1 to 5 watt panels.
If a panel puts out 2 watts or less for each 50 battery amp hours you probably don t need a charge controller.
A solar charge controller is designed to receive power from a solar panel or array of panels and use it to charge a battery or bank of batteries.
It is the charge controller that regulates the charging of the batteries.
Last summer i finally had the opportunity to set this up for demonstration with a small 12w solar panel and two different battery banks.
For example if you have a 100 amp hour battery and a 10 watt panel you take 100 and divide it by 6 600ma and you get 166 6.
The safest way to figure out if you need a charge controller is to take battery amp hour capacity and divide this by the solar panel max.
Anything beyond that and you do.
It is a device which most importantly properly charges a battery or battery bank enabling as long a life as possible.
If the number is less than 200 than you need a controller.
A charge controller or charge regulator is basically a voltage and or current regulator to keep batteries from overcharging.
Not at all times but frequently.
It detects when to allow the maximum available charge that the solar panels can produce to be applied to the batteries and it also detects when the battery is fully charged and cuts off the charge supplied by the solar panels.
It regulates the voltage and current coming from the solar panels going to the battery.
The charge process is performed in a smart or intelligent way.