When determining the required charge controller size for a 200W solar panel, it is necessary to consider both calculating charge controller amps and any amp limitations of the charge controller.
Calculating the correct amperage is done by dividing the wattage of the solar panel by system voltage; in this case, 200W/12V = 16.7A.
The amp limitation should also be taken into account when choosing a charge controller; if the chosen device has an amp limitation lower than 16.7A, then it will not be able to handle the current from a 200W solar panel and a larger size must be selected.
Calculating Charge Controller Amps for a 200W Solar Panel
Analyzing the relationship between panel wattage and charge controller amp capacity reveals an appropriate solution for a 200W system. To calculate the size of the charge controller, it is necessary to divide the total wattage (200W) by two, which gives 100W as the result. This means that a charge controller with at least 100 Watts of power is required to efficiently manage this solar panel system.
Additionally, according to Ohm’s law, the current in amperes is calculated by dividing voltage by resistance; therefore:
The number of amps needed for this 200W solar panel system can be calculated as follows: Voltage x Amps = Watts / Voltage = Amps. Using 12V as the voltage value, this formula yields 16 Amps as the minimum recommended amp size for a 200W solar panel system.
Considering Charge Controller Amp Limitations
The maximum amp capacity of a 25 amp charge controller must be taken into consideration to determine the compatibility of a 300W system.
For example, if a 200W solar panel is connected to a 25 amp charge controller, then the maximum charging capacity will be limited to 25 amps. In this case, the total power output from the solar panel would need to remain below that limit for optimal performance.
As such, it is important to consider the amperage ratings of both the charge controller and solar panel before installing them in order to ensure they are compatible with each other.
It is also important to keep in mind that different models of charge controllers have different amperage rating limits. Therefore, in order for a 200W solar panel to work properly with a 25 amp charge controller, it must either not exceed or meet its rated amperage limit.
If it exceeds this limit, then there may be potential risks associated with overloading and damaging both components. To avoid these risks, always make sure that your system does not exceed its rated amperage limit when selecting components for your setup.
Eng. Matthew Joseph Nandirio is the Founder of walkingsolar.
After graduating from the University of Houston in 2002, matt started working as a Solar Electrical Engineer for several multi-national solar energy companies.
He has a wide range of experiences including solar system requirement analysis, planning, maintaining, debugging and even solar device development through research.
He now shares his 20 years of expertise through his articles on the walkingsolar website.
Further, he is also the author of two books on Solar Technology, “Solar Power for Villages” and “DIY Solar System for Dummies”.
