Solar extension cable

The Solar extension cable set (35 metres, 6mm²) is the specialist solution for photovoltaic projects involving very long distances. If your solar panels need to be positioned in the sunniest spot on your property – for example, at the far end of a spacious garden or on a remote barn – and the inverter is located centrally within the building, this generous cross-section of 6 mm² provides the necessary capacity to effectively minimise power losses over the entire 35-metre distance.

The set includes two high-quality, double-insulated solar cables: a red cable for the positive terminal (+) and a black cable for the negative terminal (-). Both ends are professionally pre-terminated with MC4-compatible plugs and sockets. Thanks to its substantial cross-section, this set is particularly future-proof and ideally suited to modern high-performance modules, where standard cables (4 mm²) would already suffer significant efficiency losses over this distance.

Highlights at a glance

• Optimised for long distances: The 6 mm² cross-section significantly reduces electrical resistance, which is crucial for a high energy yield over a length of 35 metres (70 m total distance).
• Plug & Play installation: The cables are pre-fitted with MC4-compatible connectors at both ends, so no special crimping tools are required.
• Reliable identification: The clear colour-coding in red (+) and black (-) effectively prevents dangerous polarity mix-ups over this long installation run.
• Weatherproof & durable: The special cross-linked polyolefin sheath is UV-resistant, ozone-resistant and withstands extreme temperatures ranging from -40°C to +90°C.
• IP67 protection rating: When connected, the connectors are completely dust-tight and protected against temporary submersion (e.g. during heavy rain).
• High-quality conductor: Tin-plated electrolytic copper ensures maximum corrosion resistance and consistently excellent conductivity, even under adverse conditions.

Areas of application

This 35-metre extension cable is designed for demanding long-distance connections:

• Ground-mounted systems
  • Ideal for installing panels far away in the garden or in a field, where there is no shade cast by buildings.
• Outbuildings & Agriculture
  • Connecting garages, carports or stables located some distance away from the main building.
• Off-grid systems (24V / 48V)
  • Particularly in battery systems, the 6mm² cross-section over 35 metres is important for maintaining a stable charging voltage and minimising losses.

Installation & Safety Instructions

• Efficiency at a distance
  • With a cable length of 35 metres, 6 mm² offers a significant advantage over 4 mm². The lower resistance ensures a higher system voltage at the inverter and thus a measurably higher yield over the years.
• Protection for underground installation
  • Although the cable is weatherproof, if it is laid in the ground, it must be routed through a suitable protective conduit to protect it from mechanical damage and rodents.
• Correct engagement
  • When connecting the cables, make sure that the MC4 connectors click audibly into place. This is the only way to ensure that the connection is permanently watertight and protected against dangerous arcing.

Features

FAQs on the 35m 6mm² solar extension cable

Why is 6mm² better than 4mm² for a 35-metre length?

Due to the lower voltage drop. Over a total length of 70 metres (there and back), the resistance adds up. A 6mm² cable reduces this resistance by approximately one third compared to a 4mm² cable, which can mean a yield increase of several per cent for typical balcony solar power systems or module strings.

Will the connectors fit my inverter from Hoymiles, Deye or Growatt?

Yes. The connectors fitted comply with the global MC4 standard. They are a perfect mechanical and electrical fit for the connections on almost all standard solar modules and inverters.

Can I shorten the cable if 35 metres turns out to be too long?