How much solar power do you need?
So you want to set your rig up for Solar but you are not sure what size of set up you need? This blog is designed to give you the tools needed to be able to work out exactly what are you are drawing from your rig's batteries and what type of solar set up you need. Knowledge is key when setting up your rig for solar so the more information you have on each and every one of those home comforts devices you plan to take away with you the better. If anyone has a question pop it in the comment section below. I will try my best to answer everyone.
How to work out Watts, Amps and Volts
A larger solar panle will collect more energy in less time, but just how big does the solar panel need to be?
The power consumption of appliances is usually given in Watts. To calculate the energy you will use over time, just multiply the power consumption by the hours of use. For example:
10 watt device used over 3 hours equals 10 x 3 = 30 Watt
How to convert Amps to Watts
The energy in Watts is equal to the electric charge in Amps times the voltage in volts:
Watts = Amps × Volts
Example
If your device doesn’t have the Watts labelled on it, then it should at least have the input Volts i.e. 240V and the Amps AC it draws such as 240V – 1.5A. You can then use the equation Watts Volts x Amps so 240v x 1.5amps = 360 Watts.
How to convert Watts to Amps
The electric charge in Amps is equal to the energy in Watts divided by the voltage in volts (V):
Amps = Watts / Volts
Example
Find the electric charge in Amps when the energy consumption is 300 watts and the voltage is 240 volts.
300 Watts / 240 volts = 1.25 Amps
Do I need a battery?
Solar panels are commonly used to charge a battery – not to charge a device directly. There are a couple of reasons for having batteries. Solar panels might not generate enough wattage to directly power an appliance, but they can build up a higher wattage via a battery. Secondly a battery can regulate the power going in to the appliance at a constant rate. When solar panels are charging a battery it is usually at a varying rate which could harm an appliance if not regulated.
Battery capacity is measured in Amp Hours (e.g. 120Ah). You need to convert this to Watt Hours by multiplying the Ah figure by the battery voltage (e.g. 12V) – see calculations above.
AH refers to amp hours. This rating is usually found on deep cycle batteries. If a battery is rated at 100 amp hours it should deliver 5 amps of power for 20 hours or 20 amps of power for 5 hours.
When choosing a battery, keep in mind the equipment you will be powering and the time in which they will be running. Theoretically a 100Ah battery can deliver 5 amps over a 20 hour period (and so on). Taking into account the average small campsite - with a small 45W fridge running for 6 hours, 3 hours of 15W lighting and 20W of other electronic equipment - the minimum consumption to be expected is 335W. Take this wattage and divide it by the voltage, 12V, gives 28Ah. With the aim of leaving 50% in the battery brings the requirement to 56 Ah per day. A smarter battery setup would be to use an iTECH120 lithium battery. This new type of battery is a fraction of the weight of old style AGM batteries. AGM batteries usually weigh 35kg but and iTECH120 battery weighs just 13kg. You can also use more of the battery capacity in an iTECH120 - 80% which means its usable Amp Hour rating is similar to a 200 Amp Hour AGM. Read more about the iTECH120 HERE
What size solar panel do I need?
Solar Panels power generation is commonly given in Watts e.g. 120 Watts. To calculate the energy it can supply the battery with, divide the Watts by the Voltage of the Solar Panel.
120 Watts / 18v = 6.6 Amps
Please note that Solar Panels are not 12v, I repeat Solar Panels are not 12v. Any one who works out the Amps of a solar panels using 12v as the voltage calculation does not understand solar or has been misinformed. All solar panel voltages should be marked in the item description of our website or on the unit itself.
Check out the iTechworld Solar Panel range HERE
Inverters
The power inverter converts your storage battery power into the 240 volts AC that runs your appliances. Unless you only run 12 volt DC appliances you will need a power inverter to supply your AC.
There are 2 types of Inverters
Pure sine wave and Modified sine wave.
The Pure Sine Wave matches the power to that of which you get from your Electricity Supplier, its clean and you can run any appliances safely even sensitive equipment.
The Modified sine wave used to be considered a dirty power but some aren't as bad as they used to be, you can use this inverter type for things that don't have sensitive electronics for example fridges, cookers, pumps, You may have to be careful with some appliances such as laptops and TVs so check first.
Check out the iTechworld range of inverters HERE
Charge Controllers/Regulators
All Solar Panels 30 watts and above need a Solar Charge Controller/Regulator. A Charge Controller/Regulator is necessary to protect the batteries from over charging and supply them with the proper amount of energy to promote long battery life. If the charge isn’t regulated it can have a damaging effect on the battery being charged.
Check out the iTechworld range of Charge Controllers/Regulators HERE
Article author
Ian
ian@itechworld.com.au
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How to install 12v Solar Panels
Even if you're on a budget, it is still possible to fit a solar panel system to your caravan or Rv.
MYSTERY SURROUNDS SOLAR installation and it’s easy to see why. It would appear as though you need a physics degree and a masters in automotive electronics to adequately fit a solar system to your rig. You don’t want a photovoltaic cell to cross pollinate with a UNC anodized hex-head fixing, with the resultant loss of fluid dripping all over your neighbours cat now do you?
That is nonsense, of course, but the point is that a bit of common sense, patience and background reading on power requirements when free camping is all you need. Put away that electrical engineering course application – you won’t need it!
The basic parts you will need are several metres of insulated copper wire (we’ve used 4mm here), self-tapping screws, silicon, brackets for the panel and the key parts of the solar system – an iTechworld 100 Watt Hard Frame Solar Panel, an iTechworld 30 Amp Intelligent Regulator and an iTechworld 100Ah deep-cycle battery.
The accessories that you run off the battery are not dealt with here – this is all about harnessing free power from the sun.
Don’t be tempted to get a lower wattage panel to save money – sure, you can get an excellent 20W panel, a battery and regulator for less than $300. But that marvelous setup would only power your pocket LED torch for half an hour’s reading in your camp swag every night.
Instead, we’re assuming you are not in a swag under the stars but in a caravan with lights, television and 12V points for the likes of recharging a phone. To make a solar conversion worth the effort, you will need a minimum of a 100W Hard Frame Solar panel, 100Ah battery, Mounting brackets and a decent regulator – this is the best setup for those on a budget. ITechworld can provide this full package for under $600!!
As with all caravan DIY and maintenance projects, if you are not completely confident with the job at hand, please consult a specialist.
STEP BY STEP
1 Fit the iTechworld Mounting Brackets to your solar panel for installation on your caravan’s roof. You can use and adhesive to put the brackets onto the solar panel or screw into them with tech screws.
2 Position panel on roof with brackets attached, permitting adequate ventilation under the panel.
3 Prep roof with wax and grease remover prior to applying your silicon adhesive.
4 Preliminarily position the panel so you know where to clean. Try to position it clear of existing joins as the panel must come off to fix leaks in the join if they should occur.
5 Apply a bead of silicon to help secure the brackets with the panel attached to the roof.
6 Gently rest the brackets with the panel attached on the bead of silicon.
7 Use tech screws to help secure the panel if required.
8 Drill a hole and feed the wiring from the panel to the spot you’ve chosen as the new home for the regulator. If your van hasn’t been pre wired for solar, it will probably be necessary to drill a hole or holes, this can be sealed using the iTechworld Solar Entry gland. This will give you a waterproof point on the roof for the wiring.
9 Cut excess wire to suit. Mount regulator in desired spot.
10 Connect the wires from the regulator to the battery, making sure the positive and negatives correspond. Leave the regulator for 5 minutes this gives the regulator a chance to detect the battery voltage. Now connect the solar panel to regulator making sure the positive and negatives correspond.
11 Check the solar panel charging voltage and condition of the battery on the regulator. The job is done! Grab a beer. Brag at how good you are to your wife. Post some photos of your amazing job on Facebook,Twitter and Instagram. Invite the neighbours round to show off your new skills.
If you have decided to get the new high efficiency 100 Watt iTechworld Semi Flexible Solar Panel with American Solar Cells instead of the hard frame Solar Panels then the installation becomes a lot more specific to each situation. No brackets are needed for this installation. A lot of people glue our 100 Watt Semi Flexible panels directly to the roof however iTechworld have done research and found that if the panel has air flow underneath it will operate more efficiently.
View the Info graph on Semi Flexible Solar Panels HERE
Learn how American Solar Cells are changing the game in Australia HERE
Read how Generator Inverters work HERE
Read iTechworld Generator Reviews HERE
Read how to use a Generator Inverter HERE
Read how to avoid a drained battery HERE
Read about light weight Solar Panels HERE
Read 5 great tips to get the most out of your Solar Panels HERE
Read our comprehensive guide on Inverters HERE
Read about the benefits of travelling with Solar Power HERE
Article author
Ian
ian@itechworld.com.au
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Alternating current
So, you’re looking to purchase an inverter to run an AC-powered device off a battery or other DC source. Will you need a pure-sine-wave inverter (PSW), or will a cheaper modified-sine-wave inverter (MSW) do the job?
To answer that question, let’s begin by looking at what AC is. For starters, it’s short for alternating current. In other words, it denotes a current that repeatedly changes direction. This goes for the output of both pure- and modified-sine-wave inverters. Both are AC. What sets the two apart, is how the current changes direction and how long it stays level. Have a look at the pictures below.
As you can see, the pure sine wave features a smooth, flowing rhythm. It’s similar to what you’d think of as a “wave”. Consequently, it’s also called a “true” sine wave. This is more or less what you get in your power point at home, and it is what most household appliances are designed to run on.
In contrast to this, the modified sine wave features prolonged highs and lows as well as plateaus at zero voltage, giving it a rather squarish look. Not surprising, then, that it’s also called a “square” sine wave.
Some appliances are compatible with a modified sine wave; others are not. As a general rule, the more complex the appliance, the likelier it is that it requires a pure sine wave. But to be absolutely sure, you should always go by what the manufacturer says. To give you a better idea of how the different waveforms affect different appliances, let’s have a look at the two waveforms in greater detail, though.
Modified-sine-wave inverters
MSW inverters utilise filters to round the corners of a square wave; hence the word “modified”. As previously mentioned, however, the shape of the wave remains quite square.
Because of the plateauing peak outputs, appliances running on a modified sine wave will have to deal with more power for a longer time, and this equals additional heat. For this reason, many appliances that are designed to run on grid power will overheat if run on a modified sine wave.
Nevertheless, MSW inverters do have their place. Since they don’t require as many components as pure-sine-wave inverters, they are relatively cheap. And they typically use DC power more efficiently than PSW inverters, meaning that your battery will last longer. So, if you plan to run only normal light bulbs and induction or shunt motors, for instance, an MSW inverter will be the right choice for you. However, as previously mentioned, take heed: if you are unsure of whether your appliance will run on MSW, make sure of it before you plug it in.
Pure-sine-wave inverters
Manufacturing a PSW inverter is a lot more involved than making an MSW inverter, and this translates into a higher price. But what you get for the additional cost is peace of mind. Appliances are getting increasingly complex; these days, even seemingly simple devices feature advanced microprocessors, and, oftentimes, MSW will not agree with these microprocessors. A PSW is the only safe choice.
For example, many devices rely on a PSW to time their operation by counting how often the wave passes through zero voltage. This works well on the smooth grid AC. But when such devices are run off an MSW inverter, their microprocessors are tricked by the MSW’s plateaus at zero voltage, which results in miscalculations of time, leading to poor performance and shorter product lifespan.
A PSW inverter, on the other hand, gives you an output that is close to identical to that of household power, which makes it perfect for any appliance that you’d normally plug into the wall. One thing to keep in mind, though, is that even normal household appliances may produce abnormal loads for short periods of time. Motors and fridges, for example, may require a significantly higher wattage during 5-15 seconds at start-up. Quality PSW inverters deal with this by having a 40%-100% surge capacity. So, when shopping for inverters, always read the specifications and make an informed choice.
In short
- Modified-sine-wave inverters are relatively simple and cheap products that generally will use battery power more efficiently than pure-sine-wave inverters.
- Only basic products such as normal lights bulbs and induction or shunt motors can safely be run on a modified sine wave.
- Pure-sine-wave inverters require many components and therefore come at a higher cost. They produce current that is close to identical to that of grid AC, making them perfect for running sensitive electronics.
- If in doubt as to whether your appliances can run on a modified sine wave, always check with the manufacturer.
Read our comprehensive guide on Inverters HERE
Read iTechworld Generator Reviews HERE
Read how to avoid a drained battery HERE
Read about light weight Solar Panels HERE
Read 5 great tips to get the most out of your Solar Panels HERE
Read about the benefits of travelling with Solar Power HERE
Article author
Ian
ian@itechworld.com.au
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Determine which items you consider essential to have access to when you are the road. Consider such items as fridges, microwaves, air con units or fans, lights and other small appliances as well as medical devices such as oxygen machines.
- Determine the wattage you will need to power the items you wish to access simultaneously. This is the continuous watts. This will determine the size of generator needed. For example, a 3000 continuous wattage generator will power a fridge, small air con units, microwaves and household items.
Place your generator outside in an open area. It should be located away from doors or windows to prevent carbon monoxide from entering your living area. Make sure the area is dry. If using during rainy weather, place it under a canopy or other covering.
- Consider that generators will make noise. You may want to experiment with different locations. 7-10 meters away is usually a good starting point.
Follow manufacturers' instructions for recommended fuel and oil and for starting and running instructions. A typical 3000-watt generator will hold 6-7L of fuel and will run for approximately 6 hours.
Plug appliances and other items into the generator using a heavy-duty outdoor extension cord that is grounded. You can then plug power boards into the extension cord indoors. Charge your caravan batteries using generator power via the battery charging cables provided.
Tips
- Shut generator down and let cool before refuelling.
- Use only the oil listed in the instructions.
- Store fuel in an approved container in a locked shed or another safe area.
- Seek advice from iTechworld if you are unsure of wattage needs.
- Consider starting wattage as well as running wattage when purchasing a generator. Appliances require greater power on initial startup. Check appliances for wattage info.
- Note that Watts/KiloWatts is different from KVA.
- To prevent theft, consider running a metal ring into the ground and secure the generator with a chain.
- Make sure fuel is clean and no water or other liquids have been kept in the jerrycan.
Read iTechworld Generator Reviews HERE
Read how to avoid a drained battery HERE
Read about light weight Solar Panels HERE
Read 5 great tips to get the most out of your Solar Panels HERE
Read our comprehensive guide on Inverters HERE
Read about the benefits of travelling with Solar Power HERE
Article author
Ian
ian@itechworld.com.au
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From the Kimberly to Fraser Island, it doesn't matter if you're long range touring, or taking a weekend break, a flat or deeply discharged battery will ruin your plans and hit your back pocket.
By monitoring your power use you can easily avoid the hassle of a drained battery. From simple and inexpensive DC 12V Meters to Volt/Amp Meters or a battery monitor with all the bells and whistles, there's plenty of options to suit your needs and price tag.
iTechworld has an Amp Meter that is multi functional in the sense that it can tell you how much power you are putting into your battery from your solar panel and it can also tell you how much power you are taking out of your battery from your load.
The iTechworld Amp Meter will give you an accurate reading of the current voltage on your battery. If you want an inexpensive, easy-to-install option, this is the one to choose. The iTechworld Amp Meter offers a big and easy-to-read LED display. This means you will have no dramas monitoring how much your load is pulling out of your battery and also how much your Solar Panel is putting in.
There are a lot of regulators on the market, most of them do the same thing. If you are looking to run a smooth operation with your power then the iTechworld intelligent regulator is the controller that will help you achieve your goals.
With one touch of a button the iTechworld intelligent regulator can tell you how many amps your solar panel is putting in, how much amps you are taking out, temperature, amp hours and voltage. You can run your load directly through the controller and it will show you exactly what you are drawing from your battery right down to .0 of an amp. In the past this time of controller would cost hundreds of dollars but it is now available for just $99 via the iTechworld website.
Amp Meter Here
Intelligent Regulator Here
Learn about which Generator to choose HERE
5 tips to get the most out of your Solar Panels HERE
Learn about light weight Solar Panels HERE
Full comprehensive guide on Inverters HERE
Detailed explanation on the benefits of tavelling with Solar Power HERE
Article author
Ian
ian@itechworld.com.au
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