Introduction to Motorhome Solar Systems

Motorhome solar systems are designed to provide a reliable and efficient source of power for household appliances while on the move. These systems typically consist of solar panels, a power inverter, a battery bank, and other essential components. The primary function of a motorhome solar system is to convert DC power from the solar panels into AC power for household appliances.

To determine the right inverter size for a motorhome solar system, it’s essential to calculate the total power consumption of all appliances. This includes considering the power requirements of air conditioners, refrigerators, electric lights, and other essential appliances. The inverter size should be sufficient to handle the peak load of all appliances, including a safety margin to prevent overloading.

A pure sine wave inverter is best for sensitive devices, offering smooth and consistent output. The battery bank should be designed to provide enough power to supply the motorhome’s appliances during periods of low sunlight or at night. By carefully selecting the right components and ensuring they are properly sized, you can enjoy a seamless and efficient power supply for all your household appliances on the road.

A Basic Guide

We frequently receive questions about inverters, leading us to create this basic guide. The goal is to help you better understand how inverters work and to dispel some common myths. A pure sine wave inverter is recommended for motorhome solar systems, as it provides a stable and efficient power supply.

When selecting an inverter, you’ll want to match your inverter to what you use — both the appliance wattage and how often you run them.

This ensures that the inverter can handle the load without any issues. A high-efficiency inverter can help reduce energy consumption and minimize power losses, ensuring optimal performance.

How to size an Inverter, and analogies for better understanding

Inverters convert 12-volt battery power back up to 230-volt, also known as ‘shore power’, enabling you to operate regular household appliances. The size of the inverter you’ll need is based on the total wattage of the appliance you intend to use. It’s also important that your inverter can convert AC watts efficiently to avoid overload or power dropouts. For a clearer understanding of your power needs, consider getting a free personalised power plan. It’s important to consider both the continuous wattage and peak wattage of the appliances to ensure the inverter can handle the load.

For instance, a fridge may have a running wattage of 250W and a Nutribullet 800W, so we would need a 1200W inverter.

Once you install the 1200W inverter, we can’t then use a 1500W coffee machine, as this will cause the inverter to shut down.

Think of a single 100Ah battery as a small car, it will handle small loads like low amp charging, but if you try to run a coffee machine or charge ebike batteries it will start to protest. It might work a few times but like the car (whose clutch is now slipping) it won’t last for as long as it should. It’s important to use the correct battery voltage to ensure adequate performance, especially when powering appliances during extended use.

If we move up to a mid-sized car, we can do a lot more with it – in our analogy this would be a 200Ah battery bank with its larger ‘fuel tank’ to handle the load.

Solar power generation varies significantly between summer and winter. In winter, you may need to double your solar capacity to meet the same energy needs you have in summer. And if you’re off-grid full-time, a robust setup ensures you’re not caught short during a power outage.

So if you calculate 400W to meet your needs, you will actually need 800W. This is because the solar harvest in winter is only half that of summer (and sometimes less).

During power outages, having a reliable inverter and battery system is crucial to ensure continuous power supply.

This is often why there can be several ‘correct’ answers to the same question.

You might read, we have xyz batteries and abc solar and we use all these appliances and never run out. But what isn’t said is that they only use the rig in summer so only need half the solar of a full-timer.

This is meant as a guide to give a basic understanding, the battery references are based on AGM batteries. If you have lithium Iron Phosphate batteries or if you’re using any deep cycle battery, you’ll get more usable capacity than with standard starter-style options. The size of bank will be smaller, but also based on the depth of discharge of your particular battery.

Inverter efficiency plays a significant role in determining the backup power duration based on the load, ensuring the system is adequately powered while minimizing costs.

At Motorhome Solar, our preference for Victron Inverters stems from their consistent reliability and advanced technology. We value providing straightforward, efficient power solutions to our motorhome and caravan owners, and Victron aligns with our commitment to quality and dependability. 

Victron inverters are versatile, user-friendly, and durable, making them a practical choice for those looking to simplify their solar power setups on the road, especially when using deep cycle batteries. Victron’s range includes pure sine wave inverters, ideal for running sensitive electronics without interruption.

In choosing Victron, we aim to offer solutions that are both technologically sound and easy to manage, aligning with the diverse needs of our community.

Victron Inverters are efficient and reliable, converting DC battery power into usable energy for your everyday gear. Their advanced technology ensures optimal performance, making them a top choice for dependable power solutions.

Common issues with motorhome solar systems include inadequate power supply, inverter failure, and battery bank problems. Troubleshooting these issues requires a systematic approach, starting with checking the solar panels and battery bank for any signs of damage or malfunction. The inverter should be checked for any error codes or warning lights, and the system should be inspected for any loose connections or damaged wiring.

If the issue persists, it may be necessary to consult the owner’s manual or contact a qualified professional for assistance. Inadequate power supply can be caused by a variety of factors, including insufficient solar panel array size, inadequate battery bank capacity, or excessive power consumption. Inverter failure can be caused by overheating, overloading, or poor maintenance, while battery bank problems can be caused by deep discharging, overcharging, or poor maintenance.