What is 3S2P?
3S2P is a shortcut used when describing solar arrays, namely three panels in series per strand, two strands in parallel. Solar panels can be arranged in series, parallel, or a combination of series-parallel.
Series
Parallel
For solar panels in parallel you must purchase a set of properly sized parallel adapters to tie all the positives together and all the negatives together. This will cause the amps of each panel to add together. If a panel is rated at 8 amps and you have three panels in a parallel (1S3P or 3P) then the overall amps will be is 24 amps. When adding panels in parallel you can safely go over your solar generator's amperage rating. The reason is because a solar generator will pull the amps it needs, much like the way an angle grinder can pull many amps from the same outlet that a cellphone can use to pull a tiny number of amps.
Ecoflow Solar Parallel Connection Cable
Series-Parallel
Series-parallel is simply combining series strands in parallel to achieve better overall solar performance. For a DELTA Pro a common solar array configuration is to put three panels in series per strand and have two parallel strands, or 3S2P. If a solar panel in a 3S2P array has 37Voc and 12 amps, the array will have:
- 37 volts × 3 panels in series = 110 volts
- 12 amps × 2 parallel series strands = 24 amps
This is assuming all of the panels are have identical specifications. The array computations get much more complicated with mismatched panels.