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Advanced Wiring

Series-Parallel Combination Wiring Diagram

Jordan MitchellJanuary 20266 min read

What is Series-Parallel Wiring?

A series-parallel configuration combines both series and parallel connections to achieve the desired voltage and current. Panels are first connected in series strings, then these strings are connected in parallel. This allows you to customize your system for specific voltage and current requirements.

Key Formula

Total Voltage = Panel Voltage × Panels in Series
Total Current = Panel Current × Parallel Strings
Total Power = Panel Wattage × Total Panels

Series-Parallel Configuration Calculator

System Results

Total Panels
4
Voltage
24V
Current
20A
Power
480W
Total Wattage
480W

Series-Parallel Wiring Diagram

Series-Parallel Connection Diagram (2 Series × 2 Parallel)Positive Bus Bar (+)Negative Bus Bar (-)Panel 112V / 10APanel 212V / 10ASeriesString 1Panel 312V / 10APanel 412V / 10ASeriesString 2+-Output

Visual Diagram

Series Strings

P1
P2
String 1: 2 × 12V = 24V
P3
P4
String 2: 2 × 12V = 24V

Parallel Strings

S1
24V
S2
24V
Total: 2 strings in parallel = 24V / 20A

How to Wire Series-Parallel

1

Plan Your Configuration

Determine the voltage and current you need for your charge controller.

  • Check controller max voltage
  • Check controller max current
  • Calculate panels needed
2

Create Series Strings

Wire panels in series to achieve your target voltage.

  • Connect positive to negative within each string
  • Each string will have voltage = panels × panel voltage
  • Current stays same as panel current
3

Connect Strings in Parallel

Connect the series strings in parallel to achieve your target current.

  • Connect all string positives to positive bus bar
  • Connect all string negatives to negative bus bar
  • Total current = string current × number of strings
4

Verify Voltage

Measure the output voltage with a multimeter.

  • Check voltage matches expectations
  • Ensure voltage doesnt exceed controller limit
  • Verify all connections are secure
5

Connect to Controller

Connect the output to your charge controller.

  • Connect positive to PV+
  • Connect negative to PV-
  • Monitor system to ensure proper operation

Common Configuration Examples

2S2P (4 Panels)

4 × 200W = 800W
24V
20A
Good for 24V systems, moderate size

3S2P (6 Panels)

6 × 200W = 1200W
36V
20A
Good for 24V/48V systems, larger setups

4S2P (8 Panels)

8 × 200W = 1600W
48V
20A
Ideal for 48V whole home systems

Pros and Cons of Series-Parallel

Advantages

  • Customizable voltage and current
  • Best flexibility for system design
  • Good balance of voltage and current
  • Reduces wire size requirements
  • Works with MPPT controllers
  • Can handle large solar arrays
  • Partial shading affects only one string

Disadvantages

  • More complex wiring
  • More connections = more failure points
  • Requires careful planning
  • Need to match panel specifications
  • More expensive connectors needed
  • Harder to troubleshoot issues
  • Requires fuse on each string

When to Use Series-Parallel Wiring

Ideal Scenarios:

  • You have more than 4 panels
  • You need to match specific charge controller specs
  • You have a mix of panel orientations
  • You want to balance efficiency and simplicity
  • You have a 24V or 48V system with 6+ panels
  • You want to expand your system incrementally

⚠️ Safety Warning

  • Always add fuses/breakers on each series string
  • Never exceed charge controller voltage rating
  • Use appropriate wire gauge for total current
  • Check all connections with multimeter before energizing
  • Consider professional installation for complex systems

Need Help Choosing Your Configuration?

Use our calculators to determine the best configuration for your system.