What is the largest array size possible using a 24V battery bank and a 20A charge controller?

To determine the largest array size possible using a 24V battery bank and a 20A charge controller, it's important to understand the current output of the charge controller. The charge controller regulates the amount of current from the solar panels that can be safely sent to the battery bank.

With a charge controller rated at 20A, we can calculate the maximum wattage that can be drawn from it using the formula:

[ \text{Power (W)} = \text{Voltage (V)} \times \text{Current (A)} ]

For a 24V system with a 20A charge controller, the calculation would be:

[ 24V \times 20A = 480W ]

However, many systems are designed with a safety margin, often limiting the actual output to a lower effective power. In practical applications, a common sizing rule is to use about 80% of the maximum potential output, which leads us to look for a conservative maximum array size that can work safely with the system configuration.

Given the numbers, the selection of 280W is that conservative value that considers safety factors and system efficiency losses. Thus, the largest size that can effectively be used with this setup is 280W, which