Imagine you’re parked beside a tranquil lake, the sun is setting, and you’re ready to settle in for the night. You reach to turn on the lights—nothing happens. Your fridge has stopped humming, and your phone’s battery is dwindling. Frustrating, isn’t it? Unfortunately, this scenario is all too common for those who overlook the complexities of designing a campervan’s electrical system.
Embarking on the van life journey is exhilarating—the open road, the freedom to explore, and the simplicity of living on your own terms. But without a reliable electrical system, these joys can quickly turn into hassles. It’s not just about having the lights on; it’s about safety, comfort, and ensuring your adventure doesn’t come to an abrupt halt due to preventable issues.
Let’s look at some of the most common mistakes people make when designing their campervan electrical systems. We’ll dive into what these mistakes look like during the build, how they impact you on the road, and what it takes to fix them later.
By understanding the pitfalls, you’ll appreciate the intricacies involved and be better prepared to create a system that keeps you powered up and worry-free.
Mistake 1: Inadequate Planning
You know the old saying, “Failing to plan is planning to fail”? It couldn’t be more accurate when it comes to your campervan’s electrical setup.
Many of us, in the excitement of hitting the road, underestimate how much power we actually need. Perhaps we think minimalism extends to our energy consumption, or we assume we’ll be fine because we’re “going off-grid.”
But here’s the rub: not planning properly can lead to frequent power shortages. Imagine constantly worrying about whether your battery will last through the night or if you can charge your laptop to send that important email.
It takes the joy out of your journey and adds unnecessary stress. Plus, regularly draining your batteries below safe levels can significantly shorten their lifespan, meaning you’ll have to replace them sooner than you’d like.
Fixing this issue later often means adding more batteries or upgrading your charging methods—maybe installing additional solar panels or a more efficient alternator charger. But retrofitting these components isn’t always straightforward. You might have to rearrange your layout, redo parts of your build to accommodate the new gear or replace existing circuits with heavier gauge wires. These can all be both costly and time-consuming.
So, how do you avoid this pitfall?
Start by conducting a thorough energy audit. List every device you plan to use—lights, fridge, heater, gadgets, you name it. Note how much power each one consumes and estimate how many hours per day you’ll use them. Add it all up to get your total daily energy requirement.
Be realistic, and don’t forget to include a buffer for those days when you might use a bit more power than usual.
How to Plan Properly
While calculating your power consumption is essential, that’s just the first step. Comprehensive planning goes beyond an energy audit including:
- Battery Capacity: You need to choose the right battery size and type (e.g., lead-acid or lithium). Consider how much usable capacity your battery provides without damaging it. For example, lead-acid batteries shouldn’t be discharged beyond 50%, while lithium batteries can safely go lower.
- Charging Sources: Don’t rely on a single charging method. Whether you use solar, alternator charging, or shore power, ensure you have backups. The sun isn’t always shining, and alternators might not fully charge your batteries if you’re taking shorter trips. Integrating a combination of solar panels and alternator chargers could provide more reliability.
- Component Layout: Plan for where everything will go. Ensure components like your charge controller and inverter are accessible for maintenance and have proper ventilation. Poor layout decisions can make your system inefficient and harder to troubleshoot later.
- Scalability: Think about future upgrades. You might start with a smaller system, but if you later want to add a freezer or upgrade your battery bank, having an adaptable design will make expansion much easier.
Proper planning at the outset saves you heaps of trouble down the line.
Mistake 2: Building the System Around the Battery Size
Many people make the mistake of thinking that if they have a big enough battery bank, they’ll be set for extended periods off-grid. While battery size is important, it’s not the whole picture.
If you’re only focusing on how much energy your battery can store without considering how you’ll replenish it, you’ll eventually have flat batteries.
Why this is a problem: Your battery bank’s capacity only determines how long you can go before the inevitable happens—your batteries run out of juice. Even a large battery bank will eventually drain if you’re consistently using more power than you can harvest or generate.
In other words, it’s not just about what you take out of your batteries, but also what you’re able to put back in.
If your power consumption exceeds your ability to recharge—whether through solar, alternator, or shore power—you’ll end up with flat batteries.
This is especially problematic if you’re relying on solar panels in areas with limited sunlight or using an alternator for short drives that don’t fully recharge your system.
How to avoid this mistake
Rather than building your system around the size of your battery bank, design it around your ability to replenish the energy you consume.
- Harvesting Power: Calculate your daily power consumption (as covered in Mistake 1) and make sure you have a reliable means of generating that amount of power each day. Solar panels are great, but their effectiveness depends on location and weather conditions. If you’re relying on solar, make sure your panels are sized appropriately to cover your daily energy use, even on cloudy days.
- Charging Flexibility: Ensure you have multiple ways to charge your battery bank. Alternator charging can help during driving, but be mindful that short trips won’t fully recharge a large battery bank. Adding a shore power charger or using a generator as backup can give you peace of mind if your primary charging sources aren’t sufficient.
- Battery Size as a Buffer: The size of your battery bank is still important, but think of it as a buffer, not the core of your system. It gives you flexibility for days when you’re using more power than usual or unable to generate as much as you might need, but it shouldn’t be your only line of defence against flat batteries. If you can’t reliably recharge what you’re using, a larger battery only delays the inevitable.
Design your system with energy generation as the focus, not just battery storage. Make sure your solar panels, alternator, or other charging methods are sufficient to cover your daily power consumption.
A larger battery bank is a safety net for when you can’t generate enough power, but its size only determines how fast you’ll end up with a flat battery if you aren’t replenishing it adequately.
Mistake 3: Skimping on Quality Components
We all love a good bargain, but when it comes to your electrical system, cutting corners can cost you much more in the long run. Choosing cheap, low-quality components might seem like a smart way to save money initially, but these parts are far more prone to failure. Now, imagine being miles away from civilisation, only for your inverter to suddenly quit, leaving you powerless for critical appliances.
Our own experience taught us this lesson the hard way. While travelling in the southern tip of South America, our battery failed in the middle of nowhere—over 400 km from the nearest town. We had no choice but to drive those 400 km to find replacement batteries, only to discover they were selling at three times the price we’d have paid back in the UK.
The ordeal was frustrating, costly, and completely avoidable had we invested in better-quality components from the start.
But it’s not just about the inconvenience. Inferior components can pose serious safety hazards. Many low-cost electrical parts don’t meet basic safety standards, increasing the risk of electrical fires or shocks. This isn’t just an inconvenience—it’s a significant threat to your safety and the integrity of your campervan.
Another issue arises if you decide to replace faulty components later. High-quality parts often require specific setups, and mixing them with your existing low-grade system might lead to compatibility issues.
You could find yourself having to rework large portions of your build—replacing wires, reconfiguring your layout, and upgrading other parts, all of which lead to more downtime and unexpected expenses.
Let’s take a simple example: A cheap, unbranded inverter might cost around £100 but may have a failure rate of 10–15% within the first year. Meanwhile, a reputable inverter could cost £300 but has a failure rate of less than 1%. Replacing a cheaper inverter multiple times—especially in remote or difficult-to-access locations—will not only strain your budget but also your peace of mind.
Are CE-marked products a necessity in the UK?
Yes, products sold in the UK are legally required to meet safety standards and carry the CE mark (or UKCA mark post-Brexit for some goods). However, some non-compliant products, especially imported items or knock-offs sold online, may slip through the cracks.
Purchasing electrical equipment without proper certifications means you’re gambling with your safety. These items haven’t undergone the rigorous testing required to ensure they meet UK and EU safety regulations, making them much more likely to malfunction or pose fire hazards.
The solution?
Invest in reputable brands from the start. Look for components that meet British safety standards—keep an eye out for the CE mark, which signifies compliance with European safety directives. Yes, quality components might cost more upfront, but they provide long-term reliability, peace of mind, and a significantly reduced risk of system failure. You’ll avoid the extra costs, downtime, and stress associated with cheaper, unreliable parts, ensuring that your system runs smoothly and safely for years to come.
Mistake 4: Incorrect Wire Sizing
Wiring might not be the most glamorous part of your build, but it’s absolutely critical. Using wires that are too thin (undersized) can cause voltage drops, meaning your appliances won’t perform as they should. Even worse, undersized wires can overheat, posing a serious fire risk.
On the other hand, wires that are too thick (oversized) aren’t dangerous, but they are more expensive and take up unnecessary space—space that, in a campervan, is at a premium.
If you realise your wire sizing is off after everything’s installed, correcting it can be a major hassle. Rewiring parts of your system often involves dismantling sections of your build, which is both time-consuming and potentially costly. Plus, any delays mean you’re not out there enjoying the open road.
Let’s say you’re running a 12V circuit to power a fridge that draws 10 amps. Over a 5-metre circuit length, using a 14 AWG / 2.5 mm² wire (which is too thin) can cause a voltage drop of around 5%.
While this might not sound like much, it means your 12V fridge isn’t getting enough voltage, which reduces its efficiency and may cause it to shut off or malfunction.
More seriously, undersized wires can overheat. For instance, if the wire is rated for 10 amps but ends up carrying 15 amps due to incorrect sizing, it can overheat, increasing the risk of electrical fires.
To avoid this, take the time to calculate the proper wire sizes before you start. Use wire size calculators or charts that factor in the current the wire needs to carry, the distance it will run and an appropriate voltage drop of no more than 10%.
And remember, fuses protect wires from carrying too much current, not the devices themselves. Getting the wire size right is essential for both safety and performance.
Mistake 5: Overlooking Circuit Protection
Circuit protection might sound technical, but it’s basically about keeping your electrical system—and yourself—safe. Skipping out on installing fuses or circuit breakers can lead to serious consequences. Without them, an electrical fault can cause wires to overheat, potentially starting a fire. It can also damage your appliances or, worse, pose a risk of electric shock.
If you neglect this during your build, adding circuit protection later can be tricky. It might involve rewiring or rearranging components to fit in the necessary fuses and breakers. In the meantime, you’re running a system that’s unsafe, which isn’t worth the risk.
Imagine you’re drawing 50 amps from a battery to power multiple devices. Without a fuse or breaker, a short circuit could allow up to 100 or more amps to flow through the wires unchecked.
Wires typically rated for 50 amps would overheat and potentially ignite in under a minute.
Fuses and breakers are designed to prevent this by cutting the current when it exceeds the wire’s rating.
For example, a 50-amp breaker will trip the moment current exceeds 50 amps, protecting both the wire and the connected devices.
To steer clear of this mistake, integrate circuit protection into your design from the very beginning. Install fuses or breakers close to your power sources, like batteries, to protect the entire circuit.
Make sure to use the correct ratings for these devices, matching them to the wire size and expected load. It’s a small step that makes a huge difference in safety.
Mistake 6: Poor System Layout
When space is limited, it’s tempting to tuck components into any available nook or cranny. But a haphazard layout can lead to a host of problems. Components squeezed into tight spaces may overheat due to lack of ventilation, and long, winding cable routes can result in voltage drops, which reduce your system’s overall efficiency. And if key components like batteries or fuse boxes aren’t easily accessible, maintenance becomes a real headache.
Reorganising your system after the fact isn’t fun. You might have to tear out sections of your build, reroute cables, or even modify furniture that you’ve painstakingly installed. Not only is this process time-consuming, but it can also be expensive and frustrating.
The impact of poor layout goes beyond inconvenience. Components like inverters and batteries generate heat and need space to dissipate it. If they’re crammed into small, unventilated spaces, the temperature can rise significantly—often exceeding safe operating conditions (usually around 40°C). This can lead to performance issues or even damage your equipment over time.
Additionally, long cable runs contribute to inefficiency. A 5-metre cable run, particularly with undersized wires, increases resistance, causing voltage drops. In a typical 12V system, a 0.5V drop leads to about a 4% loss in efficiency. Over time, this inefficiency adds up, especially in a system where every bit of energy counts.
But it’s not just about lost efficiency—longer cable runs also increase costs. Longer runs require thicker wires to handle the same current load without overheating or losing voltage. Thicker wires can be significantly more expensive. For example, high-quality 8mm² wire costs considerably more per metre than 4mm², so a poorly planned layout could drive up your costs unnecessarily.
Impact of Cable Length on the Cost of Wiring
Select the amp rating from the dropdown below to see the correct wire size and indicative cost for each cable length. This helps illustrate how longer cable runs result in higher wiring costs.
Indicative costs roughly correct as at September 2024.
The solution?
Spend time planning your layout before you start building. Consider where each component will go, how you’ll route your wires, and how easy it will be to access everything for future maintenance.
- Keep cable runs as short as possible to improve efficiency and avoid the need for thicker, more expensive wires. This not only reduces voltage drops but also cuts down on material costs.
- Ensure adequate ventilation around components like inverters and batteries to prevent overheating. Follow the manufacturer’s recommendations on spacing to maintain optimal temperatures and extend the life of your equipment.
Good layout planning saves you time, money, and frustration in the long run—while ensuring your electrical system runs efficiently and reliably.
Mistake 7: Neglecting Ventilation
Electrical components like batteries and inverters generate heat, and without proper ventilation, this heat can build up and cause problems. Overheating can reduce the lifespan of your components, cause them to malfunction, or even create safety hazards like fires.
If you notice overheating issues later on, you might need to add vents or fans or even relocate components to cooler areas.
Retrofitting ventilation isn’t always straightforward—it can involve cutting into walls or cabinets, which isn’t ideal once your van is fully built out.
For example, lithium batteries often operate best below 40°C. If the temperature exceeds this, their performance and lifespan drop significantly. For every 1°C increase above the optimal temperature, battery life reduces. Inverters and chargers also suffer from heat stress, with their efficiency dropping as temperatures rise.
To prevent this, design your system with ventilation in mind from the start. Follow the manufacturer’s guidelines for spacing and airflow around components. Ensure that areas housing electrical equipment have vents or openings to allow heat to escape. This helps keep everything running smoothly and extends the life of your components.
Mistake 8: Ignoring Future Needs
When you’re in the throes of building, it’s easy to focus solely on your current needs. But as you spend more time on the road, your requirements might change. Maybe you’ll want to add a freezer, upgrade to lithium batteries, or install more solar panels. If your system isn’t designed with flexibility in mind, making these upgrades can be difficult and costly.
Retrofitting can involve significant modifications, like upgrading components, adding capacity, or even rewiring. This not only takes time and money but can also be a source of frustration, especially if you have to undo parts of your original build.
For example: consider your initial system includes a 100Ah battery and a 200W solar panel. You might think this covers your needs, but after a few months, you decide you need more power. Adding another 100Ah battery requires rewiring the system to handle the increased load. If your wires or charge controller aren’t sized for the additional power, they’ll need to be upgraded, too—potentially doubling the cost of the original installation.
The solution is to plan for scalability from the beginning. Choose components that can handle more than your current load, and leave space for additional equipment. Use wiring and connectors that are compatible with potential future upgrades. Staying informed about new technologies can also help you make choices that keep your system adaptable.
Mistake 9: Lack of Professional Guidance
Let’s be honest: electrical systems can be complex. While the DIY spirit is strong in the van life community, sometimes it’s best to seek professional guidance. Attempting to design and install your electrical system without sufficient knowledge can lead to mistakes that are not only costly but dangerous.
If you run into issues later, you might need to consult an expert to identify and fix problems. In some cases, you might even need to overhaul your entire system. This can be stressful, time-consuming, and expensive.
Let’s say you miss an essential detail, like calculating wire sizes correctly, or you forget to include circuit protection. Fixing these mistakes later could cost hundreds or even thousands of pounds, especially if you need to dismantle parts of your build.
The cost of hiring a professional upfront for a design consultation or review is often a fraction of your total system cost. A small investment can save you from spending more on fixing mistakes later.
To avoid this, consider getting professional help during the planning stage. This doesn’t mean you can’t do the work yourself, but having an expert review your plans can catch potential issues before they become problems. There are professional design services (like ours!) that can tailor a system to your specific needs, ensuring safety and reliability.
Conclusion
Designing your campervan’s electrical system is no small feat. It’s a complex task with many potential pitfalls, but by being aware of these common mistakes, you can take steps to avoid them. Proper planning, investing in quality components, and seeking guidance when needed can save you a lot of headaches down the road.
We understand that van life is about freedom and doing things your own way. But when it comes to electrical systems, the risks of going it alone can outweigh the benefits. We’re here to help you navigate these complexities, offering advice and design services to make sure your system is safe, efficient, and tailored to your adventures.
Ready to Power Up Your Journey?
Don’t let electrical issues dim your enthusiasm for van life. Whether you’re starting from scratch or looking to upgrade your existing setup, we’re here to help. Our campervan electrical design service can provide you with a custom plan that meets your needs and complies with all safety standards.
Feel free to reach out to us for a chat about your project. We’re passionate about helping fellow van lifers get the most out of their adventures without the stress of electrical woes.
Safe travels, and may your journey be bright and fully charged!
