BlueSolar 305W-20V
Victron 305W Mono wiring diagram
305W rigid mono panel, residential voltage (Vmp 32.5V, Voc 39.7V) — needs an MPPT controller with Voc headroom on a 12V bank. 1658×1002×35mm, MC4 connectors.
- Nominal voltage
- 32.5 V
- Rated power
- 305 W
- Rated output
- 9.4 A
Wiring diagram
How the 305W Mono is wired.
Open this example in Crimp to use your own parts and cable lengths. Review the assumptions and installation notes as you adapt the circuit.
Cable sizing for this example
Use the diagram as a starting point for your installation. Replace the example equipment and cable lengths with your own, and check the connections against your exact model's instructions.
3 m one way
32.5 V panel Vmp
- Wire
- 1.5 mm² · 16 AWG
- Example fuse
- 15 A
- Design current
- 9.4 A
- Voltage drop
- 2.1%
Sized against ABYC E-11. The design current is the part's continuous draw. The length is one way; voltage drop includes an equal-length return.
Run-length and manufacturer assumptions
The editable example uses 3.048 m (10 ft) runs unless a shorter run is stated. Metric overviews round these to 3 m. Adapt the parts and lengths to your installation before choosing cable and protection.
Supporting parts
- 6.1 m total of 1.5 mm² (16 AWG) marine cable
- Terminations for 1.5 mm² cable, matched to the equipment's screw terminals, leads or studs
- 15 A fuse and holder on the positive run
- Heat-shrink, strain relief and terminal boots sized to the cable
Check stud sizes, fuse type, run length and how warm the space gets against the gear you actually have before you order.
Installation notes
Before you install.
Open a question for model-specific guidance and sources.
Verified against the manufacturer's documentation (rev. Undated manufacturer datasheet; accessed 2026-10-01), checked 2026-10-01. Manufacturer documentation →
Identify the article and its ratings
The matching BlueSolar module is SPM043052002, series 4b, rated 305 W with 60 cells. Its frame measures 1658 × 1002 × 35 mm and the listed weight is 19 kg. Victron marks this article as discontinued. Match the article number when buying an older panel; a current panel with similar wattage may have different electrical data. See the model table, sheet page 1.
At standard test conditions, the table specifies Vmp 32.5 V, Imp 9.38 A, Voc 39.7 V and Isc 10.27 A. Vmp/Imp describe the maximum-power operating point; Voc/Isc are separate design inputs. Actual output changes with cell temperature, light and shade, so the catalog's daily sun-hours assumption is not a production guarantee.
Connect the module through a controller
The sheet specifies 900 mm leads with MC4 connectors. Route both leads to the controller's PV input, verify polarity, and support the leads without tension at the junction box. For a 12 V battery, use an MPPT controller that accepts this higher module voltage and the calculated cold-weather open-circuit voltage. The controller's battery output needs its own battery-side cable and protection design.
Series wiring adds panel voltages; parallel wiring adds currents. Use matching modules and check the resulting array against the controller's voltage and current limits. Cover modules during assembly and never separate PV connectors under load. See installation manual, printed pages 3–4.
Check cold voltage and protection
The exact sheet gives a Voc temperature coefficient of −0.35%/°C. Cold cells raise Voc: calculate the entire string at the site's lowest design temperature, with required tolerances and margins. The family installation manual also calls for a 1.25 multiplier on marked Voc/Isc when determining component ratings. Its 1000 V maximum module-system voltage does not permit exceeding a controller's much lower limit.
The reviewed sheet does not specify a maximum series-fuse value. Crimp's connector-current allowance is not that missing fuse rating. Confirm the module label and manufacturer requirements before adding parallel strings and selecting string protection.
Mount and inspect the panel
Use the frame's intended mounting points and a support suitable for the roof and expected loads. Do not drill new frame holes. The family manual requires at least 10 cm roof clearance for airflow, and additional support for heavier wind or snow loads. Keep drainage paths clear and do not lift the module by its cables. See mounting instructions, printed pages 5–7. Check the actual module's instructions if its frame or hardware differs from this legacy family.
Technical reference
Specifications and terminal map.
Check the model, ratings and connection points against your own unit before choosing installation hardware.
Catalog specification
305W rigid mono panel, residential voltage (Vmp 32.5V, Voc 39.7V) — needs an MPPT controller with Voc headroom on a 12V bank. 1658×1002×35mm, MC4 connectors.
- Nominal voltage
- 32.5 V
- Rated power
- 305 W
- Rated output
- 9.4 A
- Panel open-circuit voltage
- 39.7 V
Terminal map
Catalog connection points, current direction and planning limits. Check the manufacturer's pinout and connector ratings before installation.
+
positive · bidi
−
negative · bidi
Sources and sizing method
Equipment specifications. Model details, ratings and terminal roles come from the catalog. Check your unit’s label and current manufacturer documentation for its exact revision.
Example sizing. Sized against ABYC E-11. Boats built to UK or EU rules answer to ISO 13297 — check these figures against it before you build. Results use the example current and run length shown above. Set your actual equipment, lengths and installation conditions in Crimp before choosing hardware.
Read how the sizing worksNext step
Plan your installation with 305W Mono.
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