EPEVER solar charge controller

Why Do You Need a Solar Charge Controller?

by Solar PanelsVan Life
EPEVER solar charge controller

A Solar Charge Controller is a regulator for your batteries used to prevent overcharging and discharging. Solar panels are connected to the solar charge controller, as are the batteries. The Charge controller sits in the middle – it’s the link between batteries and solar panels.

You need a solar charge controller to ensure your batteries aren’t overcharged. The voltage on your solar panels can range from 16 to 32 volts or more. For example, a “12 volt solar panel” will actually produce around 18 volts, and without a load, closer to 21 volts. A “24 volt panel” will be producing around 32 volts, and without a load, close to 45 volts.

Your solar charge controller takes care of the higher voltage and ensures that your batteries are receiving the correct voltage. A 12 volt battery is fully charged at 12.6 volts. But to actually charge that battery, the input voltage needs to be over 14 volts usually, and the exact number will depend on the type of battery you have. Some people have their electrics set up as a 24 volt system. If they only had a “12 volt solar panel” – where the maximum voltage would be around 17 volts, it’s not going to have enough voltage to get the batteries charging.

A solar charge controller also prevents power from leaking back, from the battery to the solar panels at night time. Depending on the type of solar charge controller you have, it may have many other useful features, such as allowing you to stop the battery from being over discharged.

With batteries such as AGM or GEL, the amount of power they need from the solar panels changes. If they’re low on charge, they’ll absorb a lot more power. As they get closer to fully charged, they need to soak up less power – slow down the rate of charge, and this again is where the solar charge controller comes in.

PWM vs MPPT Solar Charge Controller

There are two different types of solar charge controller you can install. PWM stands for Pulse Width Modulation and MPPT is short for Maximum Power Point Tracking.

PWM controllers are an older technology and not as efficient as the newer technology MPPT solar charge controller. A PWM solar charge controller, being an older technology are generally cheaper than an MPPT solar charge controller.

A PWM solar charge controller probably still has it’s place in the scheme of things. If you’re only using it in a really small power system, perhaps an 80 watt solar panel to keep keep a battery for some shed lights used occasionally charged up.

However, MPPT controllers are so cheap these days that for most situations I’d recommend using an MPPT controller. At the time of writing, a 30 amp EPEVER Tracer MPPT Solar charge controller comes in at around $209 from Sunny Tech Solar. That would allow you to have up to a 390W solar panel at 12 volts, or 780 watts of solar at 24 volts.  

My Solar Charge Controllers

I’ve got four solar charge controllers. An EPEVER 30 amp charge controller in the van. The motorhome, because there are three different electrical systems has 3 charge controllers. A 30 amp Fangpusun PWM charge controller, a 10 amp EPEVER MPPT controller and a 40 amp EPEVER MPPT controller.

I like the Fangpusun PWM charge controller, it’s easy to use and has served me well. I bought it back when MPPT technology was a little out of my budget.

See more about my electrical set up here.

The EPEVER Solar Charge Controller

I’ve used EPEVER solar charge controllers for a number of years now without any problems. They’re easy to use, the terminals are easy to connect your wires to, and there are a couple of good accessories – the MT50 and EPEVER Solar Station Monitor.

The MT50 is connected to your charge controller and allows you more control of functions, settings and display. It gives more functionality than what you can access from the basic charge controller unit. They’re available at most RV or Motorhome stores such as RV Supercentre. People that have them say they’re worth having, but I don’t have one. I may get one, or two, in the future, but at the moment I’m using the EPEVER Solar Station Monitor.

The EPEVER Solar Station Monitor

Downloading and Installing the EPEVER Solar Station Monitor

The EPEVER Solar Station Monitor is software that you can download from EPEVER and install on your computer. I’ve got it running on an old Windows 7 laptop as well as a newer laptop. It works successfully on both.

All the files you need should come zipped in your download. Unzip the folder and install. It pays to read the instructions! The RS485 cable plugs into the communications port on the charge controller and into the USB port of your computer. I spent a little while searching on the internet for drivers for the RS485 cable, when they were actually included in the download.

You’ll need to purchase the RS485 cable. I bought my cable from Sunny Tech Solar.

The EPEVER Solar Station Monitor Interface

It’s nothing flash, seems like it was coded in the 1990’s (it probably was), probably in C# with Windows Forms, but does what it says on the tin.

You’ll need to set up your ‘solar station’ with the add station button top left. At first it can seem a bit confusing or complicated, but most people will be able to figure it out or at least know someone who can help.

I decided to use the Solar Station Monitor because I had bought ‘drop in’ Lithium batteries, that weren’t really ‘drop in’ batteries. They needed the charge settings to be changed otherwise I was getting high voltage spikes.

The Solar Station Monitor has given me the ability to input the exact settings I want. By clicking on Parameters (P) I can access the following panel which gives you the option to select your desired settings.

You can monitor in real time your load – the blue line, the input from your solar panels – the red line, and the charge going into your batteries, the green line.

The following screenshots relate to the Lithium batteries in my motorhome. Two 100 amp hour Lithium Valley batteries in series giving 100 amp hours at 24V. The Solar panels are two 370 watt panels.

The image below shows the load (blue line). That includes the Samsung 255L fridge, but in it’s off cycle, the Laptop being used plugged in and charging – just over 2 amps of draw (fridge and laptop), mobile phone plugged in charging – jumps up to just over 3 amps, the Samsung 255L fridge kicks into it’s cooling cycle, the large brief jump is the water pump being used momentarily.

The image below – Load is only the Samsung 255L fridge. The fridge cycles on and off as needed, and this is when it is in an off cycle.

Image below – fridge is cooling

Image below – fridge cycles – off, on, off, on. The one blue spike is the water pump.

Image below – fridge cycle on – every so often, perhaps twice a day it seems to do a cycle where it draws a lot higher amps.

Overall I find the EPEVER solar charge controllers to be great. And the Solar Station software gives me the option to see what’s going on if I need or want to, as well as tweak the settings for the charging inputs etc.

In the near future I plan to take some screenshots of the usage in my small van. Using the same batteries set up in parallel as 200 amp hours at 12 volts, running a 40 litre Waeco fridge, 1100 watt Nomad Pure Sign Wave Inverter with laptop, phones, and lights, a much smaller system, but also only one 270 watt solar panel.

In the meantime, be sure to check out Lake Aniwhenua – one of my favourite freedom camping spots!

Buying an RV house battery

Buying an RV House Battery: How Many Do You Need?

by Solar PanelsVan Life
Buying an RV house battery

When I was setting up my motorhome I had no idea how many batteries I would need. Other than knowing I needed a deep cycle battery, I didn’t know much else about buying an RV house battery. I started off on a budget, buying two at a good price from contacts in the automotive industry. Over time my power needs grew and I now have a total of five batteries set up as three different battery banks. See how I set up my electrical system here. If you’re looking at buying an RV house battery, the number you need will depend on many things.

Batteries are expensive and this may be a limiting factor for some people. Another thing to consider is how often you will be using them. Is it for the odd weekend away, a couple of weeks at a time, or do you live in your motorhome full time? You need to think about what your power needs are going to be, although the problem with this, as was the case for me, is that over time your power needs might grow.

Your batteries are storing the power that you want to use. That means that you need enough to get you through the times when you have no battery charging capability – overnight if your batteries are charged by solar. This might be longer if you have a period of bad whether when your solar charging capabilities are limited by cloud.

So if you’re buying an RV house battery, how many do you need? Assuming budget isn’t a factor, it’s a good idea to buy as much as you can (within reason) and solar panels to match. (enough solar to top up your batteries daily) It’s good to know you have enough battery power and solar panels to not have to worry about your power usage. Check out this article if you’re wondering how many solar panels you should have.

The RV house battery set up in my van

As a guide, in my small van I’ve been using 200 amp hours of Lithium (12 Volt) and a 270 watt solar panel. This is running lights, a small Waeco 40 litre fridge, a laptop computer most of the day and charging two phones. The most I’ve seen the batteries drop is to 70%, meaning I’ve used 30% of the 90% capacity when using lithium batteries.

The RV house battery set up in my motorhome

In my motorhome I have three different battery banks. 100 amp hours of lithium bought from Sunny Tech Solar at 24V is powering the 255L Samsung Fridge and water pump. 200 amp hours of AGM at 12V is powering lights, stereo, laptop, monitor, charging phones, and the diesel heater. 100 amp hours of AGM is being used for charging small items, lights, cigarette USB items, spark for the gas oven, spark for the gas hot water.

The minimum amount of RV house batteries I’d want to have

As a minimum I’d want 100amp hours of lithium in a small van, and in a motorhome or RV I’d want 400amp hours of lithium. If you’re installing AGM batteries or similar, you pretty much want to double the amp hours of the lithium. So 200amp hours of Lithium minimum in a small van and 800amp hours of AGM in a motorhome. Read more about how to choose house batteries for your motorhome or RV here.

Use a formula to calculate your power needs

There are more scientific methods you can use- formulas to work out your power consumption. The idea as that you buy your RV house battery to suit your exact power needs. Work out everything you want to be powering in your motorhome, use the formula to see how much power they are going to use, and then buy your RV house battery and solar panels to match this number. Thats fine, assuming you already know what you’re going to use, your power needs don’t increase over time, and you’ve factored in the weather conditions, where in the world you are (daylight hours are location dependent) and know how long you’re going to use each item daily.

Gather ideas from other motorhomes, RV’s or vans similar to yours

My suggestion is to talk to people with motorhomes, RV’s or vans, similar to what you own or are building, ask them what sort of RV house battery they have, find out how it’s been for them, how many they have, and what powered items they use in their vehicle. It’s really worth getting to know a bit about the house electrical system in your motorhome, that way if you’re camped in the middle of nowhere and something fails, you’ve at least got a chance of restoring power yourself. This all assumes you’re working with 12 volt or 24 volt power supply. Not mains power.

How to Charge RV House Batteries

Solar panels are a great way to charge your RV house battery. The sun is providing you with free energy every day. Even on cloudy days your solar panels will still work. The output will be reduced, but as long as there is light you’ll get a small amount of charging. If you think you’ll be worried about charging on cloudy days, add an extra solar panel. Instead of 1amp of charging from the panel, adding a second panel would double it to 2amps on a cloudy day.

Although not a preferred option by many due to the noise, you can use a generator to charge your batteries.

How to Charge Your RV House Battery While Driving

You can charge your RV house battery using the vehicles alternator while driving. A device called a voltage sensitive relay (VSR) is used to allow charging of the vehicles battery and the RV house battery at the same time. When the engine battery reaches 13.7volts the VSR allows charging of the RV house battery. When the engine is stopped, the voltage drops and the VSR disconnects the RV house battery from the vehicle start battery. This protects the RV house battery from voltage spikes when starting the vehicle and prevents the vehicle start battery being inadvertently drained.

Gel, AGM and Lithium batteries all have different requirements for charging. You need a charge controller that you can input the correct charging settings for your type of battery. This is pretty simple to do on most charge controllers. If you’re using lithium batteries, make sure your charge controller supports their special charging requirements. See more about my charge controllers here. I look at the EPEVER charge controllers and the EPEVER Solar Station Monitoring software.

RV house batteries

How to Choose RV House Batteries for Your Motorhome or Van

by Solar PanelsVan Life
RV house batteries

My RV House Batteries

I began my journey into RV house batteries knowing very little about them. Like most people, I knew they were something I needed in my motorhome although other than needing deep cycle batteries, I didn’t know anything about amp hours, the different types, how to use them, or what I really needed. I was on a tight budget so I also needed to get something that was relatively cheap. I started off getting two 90Amp hour deep cycle batteries, discounted at a good price from people I knew in the automotive industry. I connected these in parallel which gave me 180 amp hours at 12 volts.

As my power needs grew I bought a second battery. A 100 Amp hour 12 volt AGM battery which I also bought a small charge controller and solar panel for. I needed to get another charge controller and solar panel as you shouldn’t connect different types of batteries, or batteries at different stages of their life.

Finally, I wanted to run a household fridge on an inverter full time. I invested in Lithium batteries. I bought two Lithium Valley batteries. 100 Amp hours each at 12 volt and I have them connected in series giving 100 Amp hours at 24 volts. I plan on doing a full review of these batteries which I bought from Sunny Tech Solar soon! Read more about my electrical set up here.

Why Do You Need RV House Batteries?

Your vehicle has batteries, so why do you need to go out and buy extra batteries? The short answer is – you don’t.

But, there are so many reasons why you would want to get RV house batteries. To start with, the battery in your vehicle isn’t designed to power the appliances you would use camping, out in your RV, motorhome or van life. The battery in your vehicle is designed to supply a high current for a brief time to turn over the starter motor in your vehicle, and it’s then charged by the vehicles alternator.

RV house batteries are deep cycle batteries. They’re built to handle a deep discharge, meaning that you can use a lot more of the battery capacity, over a long period of time, charge it up again, and repeatedly do this without damage to your battery.

You might think of it as your car battery being a sprint runner, and your deep cycle battery being a marathon runner. The car battery delivers a high current for a brief period of time, whereas a deep cycle battery delivers a lower current but for an extended period of time.

So to summarize this question, you need RV house batteries because the battery in your vehicle is not designed to power the house lights, TV, or charge devices in your van or motorhome. You can do it, but you’ll be replacing your vehicle’s battery much sooner than expected.

Benefits of Having Separate RV House Batteries

Not only will it save you needing to replace your vehicle’s battery early, there are many other benefits to having RV house batteries.

You’re using the right type of battery for the purpose so it’s going to last and you’ll get your monies worth from it. A good deep cycle battery should last you at least six years depending on how you use it and care for it.

With dedicated RV house batteries you can monitor your power usage, charge them with free energy from the sun, and power the appliances you’d want in your motorhome.

Keeping your house battery and vehicle battery separate means that there’s no chance of waking up to a flat battery in your motorhome and not being able to start it.

The Different Types of RV House Batteries

Within the deep cycle battery category there are different options available.

Flooded Lead Acid batteries

Flooded Lead Acid batteries are the oldest of the options. They have lead plates that are submerged in an electrolyte mix of sulfuric acid and water. Because of this they need to be installed upright in a position where they cannot fall over and spill dangerous chemicals. They need to be outside your vehicle or in a ventilated space as they give off dangerous gas when they are charging.

Absorbent Glass Mat (AGM)

The Absorbent Glass Mat (AGM) battery is a type of Valve Regulated Lead Acid (VRLA) battery. They’re constructed from thin fiberglass mats placed between the lead plates. The fiberglass mats absorb the electrolyte and act as a damper between the plates. These batteries won’t spill any liquid, they’re sealed, and can usually be installed in any position.

Gel batteries

A gel cell battery is another of the VRLA batteries similar to the AGM battery. The electrolyte, sulphuric acid and silica is mixed together and becomes a gel like substance. Like AGM batteries, gel batteries can be installed in any position, they won’t spill and are maintenance free. They don’t give off dangerous gas like flooded batteries so can be installed inside. Both AGM and Gel batteries have better resistance to vibrations – the gel make up of the battery tends to absorb extreme vibrations in contrast to a wet cell battery.

Lead Carbon batteries

Lead Carbon batteries are a new type of VRLA lead acid battery. They use a common lead positive plate (anode) and a carbon composite negative plate (cathode). Lead Carbon batteries are supposedly a step up from AGM and Gel batteries and often seen as a rival to LiFePo4 (Lithium) batteries.

LiFePo4 (Lithium) batteries

Lithium batteries offer many advantages over AGM and Gel batteries. Although the initial cost is much more than AGM and Gel batteries, the cost is offset by the longer lifespan of Lithium batteries. Lithium batteries are safe to install inside and in any position. They are much lighter in weight than traditional batteries which is good for small van conversions or any situation where you need to give consideration to the vehicle weight. Most lithium batteries can be discharged 90 percent. Lithium are much faster to charge than other deep cycle batteries. Whereas traditional batteries may take most of the day to recharge, your lithium batteries can be recharged by mid morning on a sunny day.

Best Type of RV House Battery

The best type of battery to use as your house battery is most likely dependent on your budget and how you intend to use your motorhome. AGM and Gel batteries are great for those on a lower budget. In my opinion, the ultimate battery if you can afford it is to install Lithium batteries. Lithium batteries tend to be more expensive, but again, they’re worth it. If you’re wondering how many you’d need, read more about that here. They offer so many benefits and are really worth the investment especially if you live full time in your vehicle. Lithium batteries charge fast and soak up any energy the sun throws at them from your solar panels. Wondering how many solar panels you then need? Check out our article about solar panels here.

How I Set Up My RV Power Supply System

by Solar PanelsVan Life

All the information on the internet about how to set up an RV power supply for your motorhome or van can leave you feeling overwhelmed.

There are many different ways your electrical system can be set up and so many different components, brands, and recommendations. I found it helpful to look at what other people were using in their campers and I was then able to get an idea of what I might need. The perfect RV power supply set up for your camper will come down to the needs of each individual. What do you intend to power? How often will you be away in your camper, or are you living in it full time? How much money do you want to spend on it all?

A Small RV Power Supply Set Up

I had decided I wouldn’t need much in the way of solar panels and batteries and would have very little power usage. My RV power supply would be for a little portable chiller, a few lights and charge my phone and laptop. I purchased two 12 volt 100 amp hour batteries and a 150 watt solar panel with a PWM charge controller. Very basic.

RV Power Supply Needs Grow…

Over time my RV power supply needs grew. I added another battery and solar panel. It’s not recommended to mix new batteries with old batteries or different types of batteries. So I now had two solar systems set up. This wasn’t the ideal way to set up an RV power supply but it worked for now.

And then I went even bigger. I had moved in and was living in my motorhome full time. I now have every thing I could want in the motorhome and as such my power needs had grown.

Solar panels for RV power supply

The motorhome now has three different electrical systems with solar panels and batteries for each. Check out more about how to choose batteries for your electrical set up here.

System One

2 x 12volt 100Amp/hr batteries for a total of 200 Amp/hrs.

2 x 150W solar panels

1 x 30A PWM charge controller

I use this for the lights, diesel heater, and an 1100W pure sign wave inverter. This powers any 240V mains appliances such as laptop and monitor.

System Two

1 x 100amp/hr AGM battery

1 x 90 watt solar panel

1 x 10A EPever solar charge controller

This is powering the car stereo and 12V cigarette lighter sockets for USB charging of devices, and items like the gas hot water heater and gas oven get their spark from it.

System Three

2 x 100 amp/hr Lithium batteries. 100Amp hours @ 24V

2 x 370W solar panels

1 x 40A EPever solar charge controller

These power the water pump and Samsung Digital Inverter fridge

This isn’t the most cost effective way to put an RV power supply system together for your motorhome. I wouldn’t recommend it, but sometimes this is simply what happens. Over time you realize you really want to run more electrical items on your travels. If you’re wondering how many solar panels you really need, check out this article here. Most of my electrical components were bought from Sunny Tech Solar.

EPEVER Solar Station Monitor

I use the EPEVER Solar Station Monitor software on my laptop. It’s a great way to adjust charging settings and to monitor your solar input and loads. It’ll run on old laptops, or at least it runs OK on my old Windows 7 laptop.

You’ll need to buy a special cable that connects from the EPEVER charge controller to your USB port on your laptop. It’s called an EPEVER PC Communication Cable CC-USB-RS485-150U.

The image below is a snapshot of my system at this time… Blue line = power I’m using, Red line is the power from the sun, Green line is what’s going into the battery. This is 200amp hour lithium battery at 24Volts and 780W of solar. It’s a 24V system.

It shows a time period between about 2.15pm and 2.45pm in this picture. The load (blue line) starts out at just over 2amps. That’s my laptop I’m using which is also charging. The load (blue line) increases to just under 4 amps which is where I plugged my mobile phone in to charge. The next increase which takes the load to almost 5 amps is where the Samsung 255L fridge cycles on. The big spike up to 8 amps briefly is the water pump – tap being used.

The red line is what I’m getting from the solar panels. The batteries are pretty much full, and on a float charge so the green line – what’s going into the batteries is maintained by the charge controller at pretty much zero.

One downside of the EPEVER system is that you don’t really know what your solar panels are putting out in the way of amps UNLESS your batteries are way down and soaking up the sun power. In contrast, I have an old PWM controller on which the display shows exactly what you’re getting from the sun – perhaps 12amps, and the next screen shows 2 amps actually going into the batteries. (or similar figures)

See more about my charge controllers and the EPEVER Solar Station Monitor here.

Pros and Cons of Three RV Power Supply Systems

I like having each separate system though. It gives redundancy, meaning if something breaks in one of them I still have power. Eventually I’ll reduce it from three systems down to two. I definitely recommend using Lithium batteries. The motorhome is well equipped for electrical needs. I don’t ever find myself running low on battery power or having to conserve power usage. I’m able to do all the normal things, I charge two cell phones daily and run a laptop and monitor all day every day. I’ll put the stereo on and use all the lights at night. It’s like living in a little apartment on wheels and the power is provided by the energy from the sun. With the combination of batteries and solar panels on the roof of the motorhome, I never have to worry about how much power I’m using. Even in the winter after a few cloudy days, I still have enough in the batteries. The solar panels will generate enough power even on cloudy days to keep the batteries from getting too low.

RV Power Supply Set Up for My Van

My van is a much simpler set up.

I have one 270watt solar panel, 200amp hours of Lithium battery at 12V, a 40 Amp EPever solar charge controller, and an 1100watt pure sign wave inverter. I run a little Waeco 40 litre fridge, and charge the laptop and mobile phone all using the inverter. Lights are 12V LED strip lights. I have a diesel heater for the winter, and these draw high amps on start up for a short time.

How Many Solar Panels Do You Need?

by Solar Panels

I’ve often sat outside my van or motorhome, soaking up the sun, wondering how many solar panels do you need on the roof. The panels I have seem to work great, but I wonder if there is an optimal amount of solar panels to put on your RV, motorhome or van. I decided to do a bit of digging on the internet to answer the question of how many solar panels do you need on your roof.

Benefits of Solar Panels

Having solar panels on your motorhome, van or RV is a game changer. Instead of relying on the vehicles alternator to charge your house battery, you get free energy from the sun. There’s no need to be driving, using expensive petrol or diesel for your batteries to charge. You can park up by the lake, river, beach or the middle of nowhere, and as long as you have daylight your batteries will charge.

Generally speaking, solar power is easier and safer to install than AC mains supply. You can get your solar system professionally installed or you can do it yourself. An AC mains supply where you hook up to camp ground power should be done by a professional and must be signed off by a professional before it is legal.

There’s no moving parts or mechanics to maintain with solar panels. Compared to a generator or wind turbine solar panels are efficient, virtually maintenance free, and silent. So, how many solar panels do you need?

How many solar panels do you need on the roof?

How Many Solar Panels Do You Need? Two Schools of Thought

There are at least two schools of thought on the question of how many solar panels do you need to have. Some people will give you a definitive answer, and others will say it depends.

There are formulas you can use to work out how much power each appliance you intend to use consumes, and from there you work out how many hours a day you’ll use them, which gives you an estimate of your daily power usage and therefore how much output you need from your solar panels. You can even find nifty calculators online that you can input the numbers and it will provide an answer.

The other school of thought is that you can never have enough solar panels, or at least – the more the better and get what you can afford.

I’d pick a mix of these two, I’m probably in the middle although leaning towards the, “you can never have too much solar”.

You can input numbers and come up with a figure on paper, but do you really know every appliance you intend to use and for how long each day? What if you only want to charge a laptop computer initially, but later on find you need to run two laptops plugged into good sized monitors all day? Possibly a bit far fetched but not unheard of.

Solar is very dependent on the weather and season. What if you get two or three weeks of bad weather that limits your daily charging? When working out your numbers by the first method all this needs to be factored in. In winter there are less daylight hours and the sun is lower which equates to less charging.

I have 1100 watts of solar panels on my motorhome which is approximately two thirds of the roof space covered. As one person put it, no one ever regretted having too much solar but many have regretted having large battery capacity and not enough solar. In reality, numbers on paper can be very different to motorhoming in real life.

My van has one 270 watt panel. Given I don’t use as much electricity in the van my 270watt panel is adequate. Click here to read about my solar and electrical set up in my motorhome and van.

The Different Types of Solar Panels

There are three main types of solar panels that you’ll hear about. Monocrystalline, polycrystalline and thin-film solar panels.

Monocrystalline panels are the oldest type of panel and also the most developed technologically. They’re made from a single (mono) crystal silicon solar cells. They’re considered to be a premium panel with a high efficiency and output. They’re recognizable by their black, uniform appearance.

Polycrystalline panels are less efficient although often more affordable. The polycrystalline cells are also made from silicon but in contrast to the monocrystalline panels, these are made from many (poly) fragments of silicon crystal melted together. These panels appear bluish in colour and speckled as the light reflects of the many crystal fragments.

Thin-film solar panels are thin and flexible. They’re made from layers of semiconducting materials such as silicon, copper indium gallium selenide and cadium telluride. These panels tend to have a lower efficiency compared to crystalline panels.

Best Type of Solar Panel

You’ll likely be choosing between monocrystalline and polycrystalline panels. The best type will depend on your circumstances. How much roof space do you have and what can you afford? Polycrystalline panels are somewhat cheaper but less efficient, you might need more of them, whereas if your roof space is limited you might choose to pay a bit more for monocrystalline panels which will be more efficient but less of them needed. How many solar panels do you need for your installation? It’ll likely be dependent on the type of panel you install.

Fixed Solar Panels or Portable?

During my travels I’ve seen motorhomers with portable solar panels. This can be an option to supplement your panels on the roof or an option if for some reason you don’t want to mount panels to your roof. Keep in mind however, that a portable panel is probably not going to provide enough energy output for a normal to moderate user of power. It may be fine if you just want to charge a phone, laptop, run your lights at night and a few other small items, but you’d need to watch your usage.

A portable panel would be ideal to supplement your existing panels on the roof. Panels flat on your roof don’t put out as much power as a panel aimed directly at the sun. In winter, being able to point your panel at the sun can make a huge difference to the panels output. Therefore in winter time a portable panel would be ideal to supplement what you have on the roof.

In the summer time you may want to park your vehicle in the shade during the hottest parts of the day. Having a portable panel with a long lead means you can still get charging for your batteries if you can place the panel in the sun while your vehicle is in the shade.

How Many Solar Panels Do You Need for Cloudy Days?

Your solar panel will work on most cloudy days. A very cloudy day with really thick dark clouds may mean that it won’t work at all though. But on most cloudy days you’ll be able to get solar output although it will be a lot less than on a sunny day. This is the reason you want to have as many solar panels as you can. So how many solar panels do you need to get you through cloudy weather? On a cloudy day one solar panel might put out 1amp. If you have two you now get 2 amps. Four panels equals 4 amps. There are other factors at play, but in short this is the principle idea behind having plenty of solar. On those cloudy days you’ll have enough to get by.

Solar Panel Maintenance

To get the most from your solar panels you should ensure they’re clean. Even a small amount of debris, dead leaves or dirt on your panel can reduce it’s output dramatically. A mild detergent in water is safe to use on your panels. During cleaning you can also inspect any connections that you can see to ensure they’re secure and free from damage.

What Components Do You Need for a Solar Power Set Up?

Your solar panels are connected by cable to a solar charge controller. This in turn is connected to your battery. Your battery gives you power, either as 12 volt, 24 volt or even 48 volt depending on your system. Most motorhome, van or RV set ups will be 12 volt. You may also have an inverter which can provide you with mains power.

The charge controller is an important part of your solar power system. There are two types of controller. PWM and MPPT. For more about solar charge controllers read our thoughts here.

Your battery is connected to the charge controller. There are many types of battery available including lead acid, GEL, AGM, Carbon, and Lithium. Check out our guide about batteries for your motorhome, van or RV here.

Check out our tips for van life traveling here.