Effect of series vs parallel panel configurations on charge controller?

Series vs Parallel Configurations

When designing a solar array, choosing between series and parallel configurations affects charge controller sizing. In a series configuration, the total voltage of the array is the sum of individual panel voltages. However, the total current remains the same as the lowest-rated current among the panels. As a result, the charge controller must be sized to handle the total current and voltage of the array.

Charge Controller Sizing Considerations

When sizing a charge controller for a series configuration, consider the total voltage and current of the array. For example, a 12V array with 3 panels in series, each with 10A current rating, would require a charge controller rated for 30A and 36V (12V x 3). In a parallel configuration, the total current is the sum of individual panel currents, so the charge controller must be sized to handle the sum of the currents of all the panels.

Real-World Example

Consider a 12V solar array with 4 panels in parallel, each with a 20A current rating. The total current would be 80A, and the total voltage would remain 12V. In this case, the charge controller would need to be sized for 80A and 12V. Using a charge controller rated for 100A and 24V (2x 12V) would be sufficient, as it can handle the combined current and voltage of the array.