This archived drawing shows four solar panels arranged as two panels in series per string, with two strings in parallel, often abbreviated 2S2P. The two numbers describe the electrical grouping; they do not specify panel wattage, battery voltage or controller capacity.
Follow The Two Strings
Start with the upper pair of panels and trace the connection between them: they form one series string. The lower pair forms the second string. The two strings then run toward the joining connectors at the right side of the illustration before the shared pair passes through the roof-entry gland.
The lower part of the image places the array alongside an isolator, charge controller and battery-side equipment. These pictured components provide context for the reference.
Separate String And Array Values
With four matched panels in the simplified model, each two-panel string has the sum of two panel voltages and the current of one panel. Joining the two equivalent strings in parallel adds their currents while retaining the string voltage. Keep those two stages separate when comparing the drawing with panel datasheets.
Record the panel model and quantity in each string, followed by the proposed combining hardware and controller model. Check the controller’s applicable input limits against the actual array data, including temperature effects on open-circuit voltage. Also retain the equipment instructions that determine wiring, connectors, isolation and protection.
For the underlying series/parallel principles, see Victron Energy’s Wiring Unlimited: DC wiring. Check the instructions for the exact equipment being considered.
Compare The Arrangements
Compare the series diagram, parallel diagram and two-series, two-parallel diagram. Keep the selected drawing, panel datasheet and controller manual together in the van-build decision log.
Reference guide expanded October 20, 2026. Original publication date and archived references retained.