Semloh 25m Caravan Electrical Hook Up Cable Review: A Genuine 2.5mm Copper Lead for Reliable Power
- Caravan Coach
- 4 days ago
- 6 min read
Product Category: Caravan Electric Hook Up Cable / Mains Extension Lead
Brand: Semloh (part of Crusader / AutoMotion Factors Limited)
Prices Usually Range From: £38 - £45
Best For: Caravanners who want a properly specified hook up cable that meets British Standards and carries the full 16A supply safely
Where to Buy: Available at OBI Camping & Leisure, Camping Online, or major retailers like Amazon
Caravan Electric Hook Up Cable - Introduction
Finding a quality hook up cable sounds straightforward, but the market is flooded with cheap leads that use undersized conductors. The Semloh ML25 stands out because it uses genuine 2.5mm² copper cores throughout its 25 metre length. This matters more than most beginners realise, and I will explain exactly why with some simple maths shortly.
Semloh is part of Crusader, a well-established UK supplier of cable products and electrical accessories to the leisure vehicle market. They have been producing hook up leads that meet CE and BS Standards for years, making this a name you can trust when it comes to electrical safety.
The 25 metre length is worth noting specifically. Both the Caravan and Motorhome Club and the Camping and Caravanning Club specify 25 metres as the recommended length because UK campsites position their electric bollards within 20 metres of each pitch. Choosing a shorter cable to save weight or cost may limit your pitch selection options, particularly on larger sites or when popular spots are taken.
Why 2.5mm Cable Thickness Matters
This is where many caravanners get caught out. Cheaper hook up cables often use 1.5mm² conductors, which can cause serious problems.
Here is the simple maths that explains why:
A typical UK site bollard provides a 16A supply at 230V. Using the formula Power = Voltage × Current, this gives you: 230V × 16A = 3,680 watts (3.68kW) of available power.
A 1.5mm² cable at 25 metres experiences a voltage drop of approximately 9V under full load, which is about 4% of your supply. The IET Wiring Regulations (BS 7671) recommend keeping voltage drop below 3%.
A 2.5mm² cable experiences only about 5.5V of voltage drop at 25 metres, roughly 2.4%, keeping you within the recommended tolerance.
The practical consequences of excessive voltage drop affect your appliances directly. Your caravan fridge monitors incoming voltage, and if it drops too low, the fridge interprets this as a power failure and switches to an alternative power source such as gas. When the voltage is hovering around the threshold, the fridge clicks in and out between power sources repeatedly, which is both annoying and inefficient. Other appliances, such as kettles and heaters may work to a lesser effect, taking longer to boil or producing less heat.
More seriously, undersized cables carrying high loads generate heat. As current flows through a conductor, resistance causes the cable to warm up. This is manageable with properly rated cable, but with undersized conductors the heat builds up. If the cable is left coiled rather than fully unwound, the heat cannot dissipate and accumulates further. In worst case scenarios, this can cause the insulation to melt and potentially start a fire. This risk is why BS 7671 specifies 2.5mm² cable for this application.
Key Features
The Semloh ML25 is a 25 metre orange hook up lead fitted with 16A CEE connectors at both ends. The high visibility orange colour is recommended by both the Caravan and Motorhome Club and the Camping and Caravanning Club, with many sites only permitting orange cables for safety and visibility reasons.
Construction uses three cores of 2.5mm² stranded copper cable with PVC insulation and sheathing. The connectors are IP44 rated, meaning they offer protection against solid objects larger than 1mm and water splashing from any direction. This makes them suitable for outdoor use in typical British weather conditions.
The cable conforms to BS 7671, BS6500, EN 60309-1 (plug), and EN 60309-2 (connector). These certifications matter because they confirm the cable has been manufactured and tested to recognised safety standards, unlike many budget imports that may claim 16A ratings without meeting the underlying specifications.
Once you have connected to the site bollard, it is worth checking that the supply is correctly wired. A simple socket tester like the Martindale BZ101 Buzz-It can quickly verify that live, neutral, and earth are connected correctly, which is especially useful when touring abroad where reversed polarity is common.
Pros and Cons
Pros:
Genuine 2.5mm² copper conductors throughout, not undersized 1.5mm
Meets BS 7671 and EN 60309 standards
IP44 weatherproof connectors
High visibility orange colour accepted on all UK sites
25 metre length reaches all UK pitch positions without limiting your choices
Made by an established UK supplier with good reputation
Cons:
Heavier than cheap 1.5mm alternatives due to thicker copper cores
Costs more than budget cables, though quality justifies the difference
Does not include a storage reel (sold separately)
Performance
The connectors fit securely into site bollards and caravan inlets, with the locking mechanism working smoothly. The cable remains flexible even in colder weather, which makes coiling and storage easier during spring and autumn trips.
The thicker 2.5mm cable does make it heavier than budget alternatives, and this is something to consider if storage space is limited. However, this weight reflects the proper amount of copper inside, which is exactly what you want for safe electrical supply. Always fully uncoil the cable when in use. Leaving it wound creates a coil that traps heat, and even properly rated cables can overheat if not laid out straight. Lay excess cable in loose figure-of-eight patterns under your caravan rather than leaving it coiled.
The weatherproof rating holds up well in real conditions. I have left the connection outside during heavy rain without water ingress, provided the protective covers are properly closed. The connectors prove durable over multiple seasons of use, with minimal wear to the locking mechanisms.
Specifications
Length: 25 metres (recommended length for UK sites)
Cable Type: 3-core 2.5mm² stranded copper
Voltage: 230-240V AC
Current Rating: 16A (cable rated to 20A)
Connector Type: 16A CEE (IEC 60309) plug and coupler
IP Rating: IP44 (splash proof)
Colour: High visibility orange
Standards: BS 7671, BS6500, EN 60309-1/2, CE approved
Approximate Weight: 5kg
Why It's Recommended
The Semloh ML25 is recommended because it delivers exactly what a hook up cable should: reliable, safe power transfer with properly specified components. In a market flooded with cheap alternatives that cut corners on conductor size, this cable uses the correct 2.5mm² copper cores that BS 7671 specifies for this application.
For beginners, this might seem like an unnecessary expense when cheaper cables are readily available. However, the maths does not lie. Running appliances near the maximum draw through undersized cables risks overheating the cable itself, which in the worst case can lead to fire. Even without catastrophic failure, voltage drop affects how your appliances perform. Fridges may switch repeatedly between mains and gas, which is frustrating when you are trying to keep food cold for a week away.
The 25 metre length ensures you can reach any pitch position on a UK site. Shorter cables may save a small amount of weight but could leave you unable to take the pitch you want, or force you into awkward cable routing that creates trip hazards.
The established reputation of Semloh and Crusader in the UK leisure market adds confidence. This is not a no-name import that may or may not meet the standards printed on its packaging. It is a cable from a supplier who has built their business on providing reliable electrical accessories to caravanners for years.
Rating
Overall Score: 4.5/5
Score Breakdown
Design: 4/5
Durability: 5/5
Ease of Use: 4/5
Value for Money: 5/5
Disclaimer
This review reflects our genuine opinions and experiences. Some of the links in this article are affiliate links, including Amazon Associate links. As an Amazon Associate, we earn from qualifying purchases. This means we may receive a small commission if you buy through these links, at no extra cost to you.
Product details, availability, and prices were accurate at the time of writing but may change without notice. Please check with the retailer for the latest information before making a purchase. Caravan Coach cannot be held responsible for differences between this review and the actual product or service you receive.
