Solar extension cable 25m 6mm² - red/black for reliable PV applications (set)

The Solar extension cable set (25 metres, 6mm²) is the high-performance solution for photovoltaic projects where maximum efficiency and minimal losses over long distances are paramount. If you need to bridge a distance of 25 metres between your solar modules and the inverter, this generous cross-section of 6mm² provides the necessary reserves to safely carry the generated energy to its destination without any significant heat build-up.

The set includes two high-quality, double-insulated solar cables: a red cable for the positive pole (+) and a black cable for the negative pole (-). Both ends are professionally pre-assembled with MC4-compatible plugs and sockets. Thanks to the solid cross-section, this set is particularly future-proof and ideal for modern high-performance modules that often deliver high currents and where standard cables already reach their limits at this distance.

Highlights at a glance

• Lowest line losses: The 6mm² cross-section significantly minimises electrical resistance and ensures a much lower voltage drop than conventional 4mm² cables over 25 metres.
• Plug & Play installation: The cables are pre-assembled on both sides with MC4-compatible connectors, so no special crimping tools are required.
• Secure identification: The colour coding in red (+) and black (-) effectively prevents incorrect polarity and makes installation easier, even on more complex systems.
• Weatherproof & durable: The special jacket made from cross-linked polyolefin is UV-resistant, ozone-resistant and withstands extreme temperatures from -40°C to +90°C.
• Protection class IP67: The connectors are absolutely dust-tight and protected against temporary submersion (rain/puddles) when plugged in.
• High-quality conductor: Tinned electrolytic copper ensures excellent corrosion resistance and permanently high conductivity, even in demanding environments.

Areas of application

This 25-metre extension is optimised for demanding long-distance connections:

• Large balcony power stations & garden systems
  • Ideal for placing modules at the sunny end of a garden or on a carport and routing the electricity to the house with minimal loss over 25 metres.
• Rooftop systems & barns
  • Bridging the distance from distant module strings to the entry point into the building or to the central inverter.
• Stand-alone systems (12V / 24V / 48V)
  • Especially critical for battery systems: Over 25 metres, the 6mm² cross-section ensures that the charging voltage arrives virtually without loss, which noticeably increases the efficiency of your storage.

Assembly & safety instructions

• Efficiency advantage at distance
  • With a cable length of 25 metres, 6mm² provides a significant advantage over 4mm². The reduced resistance means a higher system voltage at the inverter, resulting in a measurably higher yield.
• Strain relief & fixation
  • Fix the long cable runs every 50–100 cm to the mounting frame or in cable ducts using UV-resistant cable ties to prevent mechanical strain on the connectors.
• Proper latching
  • When connecting, make sure that the MC4 connectors audibly latch. This is the only way to ensure that the connection is permanently waterproof and safe against dangerous arcing.

Features

FAQs about the Solar Extension Cable 25m 6mm²

Why should I use 6mm² for 25m?

To minimise power losses. At a length of 25 metres (50m total run) the resistance adds up. 6mm² cables have around a 30% lower resistance than 4mm² cables. This means less heat lost in the cable and more usable energy for your inverter.

Do the connectors fit modules from all major manufacturers?

Yes. The supplied connectors comply with the global MC4 standard. They fit perfectly both mechanically and electrically with connections from brands such as Trina, Jinko, JA Solar or Canadian Solar.

Can I shorten the cable if required?