Big off-grid photo voltaic and battery backup PV systems normally involve bigger charging than a single controller can offer. To fulfill substantial electrical power charging demands, many photo voltaic controllers may be connected in parallel to some battery bank with every single controller linked to its individual individual PV subarray.
For MPPT controllers, MPPT monitoring of each and every subarray is favored, as you can find much less impression with voltage mismatches. Also, failure with one controller will likely not affect the solar production in the remainder of the array. A further thing to consider is usually that BOS necessities for much larger arrays could be more challenging. Therefore, various photo voltaic controllers with separate subarrays should be considered not merely possible, but exceptional.
When making use of parallel solar controllers, the battery have to be sized to take care of the blended charging present-day as encouraged by the battery manufacturer. It’s also imperative that you take note that every controller can have its personal individual solar array, with each and every array configured in accordance with all the solar controller specs.
Through absorption (or increase) charging, the parallel controllers will commence restricting the voltage at about a similar time, because they may all be sensing the same voltage and also have exactly the same charging profile. The controllers could end absorption charging at a bit distinctive moments, but this may usually be of minimal or no consequence.