Solar PV with Battery Storage
A small DC system: a PV array and a battery share a DC bus through a combiner, feeding a 12 V load. DC has polarity rather than live and neutral, and both rails matter just as much.
Components Needed
Text Wiring Path
PV + → Combiner → Battery + and LED + PV − → Battery − → LED −
Schematic
Steps
- 1Place a Solar PV Panel as the source and a 12 V battery as the storage.
- 2Place a DC combiner (here a Wago connector) to join the sources onto one bus.
- 3Run DC+ from the panel into the combiner, then out to the LED positive and the battery positive.
- 4Run DC− from the panel to the battery negative, and on to the LED negative.
- 5Press Run: the LED lights from the shared bus.
- 6Open the battery positive in the Fault Lab — the LED keeps running, because the panel is still on the bus.
DC has a positive and a negative rail, not live and neutral, and polarity decides which way current flows. Sources sharing a bus can each support the load, which is the point of storage: the panel runs the load and charges the battery at the same time.
A PV array is live whenever light falls on it, and DC arcs do not self-extinguish the way AC arcs do. Isolate at the DC isolator before touching a connector, and remember a battery can deliver fault current far beyond what its size suggests.
Terms used here
Defined in the glossary — each one opens at its own entry.
Now wire it for real.
Build this circuit in the browser, inject a fault, and watch the protection respond.