HOW TO CHOOSE THE RIGHT INVERTER
There are a few different styles of inverters on the market – we show you what type best suits you.
MODIFIED SINE WAVE
* Wide range, plenty of choice
* Inexpensive compared to PSW
* Generally smaller than PSW
* Not suited for sensitive electronics
* Create more heat than PSW inverters
* May not work with all appliances
The Modified Sine Wave (MSW) inverter’s main strength is its relatively cheap price when compared to a Pure Sine Wave model. For most purposes an MSW inverter will suit, as they are ideal for most devices with the exclusion of sensitive electronics. Modified Sine Waves may cause some distortion on TV and computer screens and they are not recommended for constant use with battery powered items like laptops as they can eventually damage the battery – occasional use is fine though.
PURE SINE WAVE INVERTERS
* Smooth and reliable power output
* Able to power any device within
* Runs more efficiently than MSW
* Higher cost than MSW
* Physically larger and heavier than MSW
Pure Sine Wave (PSW) inverters are more expensive than other models and are generally larger because of the added circuitry and sophisticated electronics they utilise. Though they are more expensive, PSW inverters can be relied upon to deliver excellent constant power and that’s why they are trusted to power sensitive devices as well as medical equipment.
DIFFERENT TYPES PORTABLE INVERTERS
* Small and portable
* Easy to use
* Low power output
* Can’t be easily mounted
* Very few are PSW
Portable inverters are the cheapest, easiest to use and most compact. Some, like the WAECO offering are nicknamed can-inverters, as they’ve been designed to fit into your vehicle’s cup holder for ease of access and to avoid needing to be permanently mounted. Available in sizes up to around 150W, portable inverters generally have a cig-plug so that you can easily connect and disconnect it from your vehicle while you’re on the go.
* All-in-one package
* Simplifies your 12 and 240 volt system
* Available in MSW and PSW
* High cost
* Large physical dimensions
* More difficult to install
Inverter Chargers combine the off the- grid usefulness of an inverter, with the ease and simplicity of a 240 volt battery charger. They are an all-in-one package that allow you to pull into a powered site, hook up your van and know that while your batteries are being charged to an optimal level, you’re still able to use the inverter. Similarly, if you’re visiting a remote free camp, you can use a generator directly into your inverter charger to replenish your batteries and utilise the refined 240 volt output. Inverter Chargers are available in both Modified and Pure versions and they cost considerably more than an inverter, however they offer a whole new dimension of uses.
12 VOLT vs 24 VOLT
Inverters are available in both 12 and 24 volt input models. A 24 volt inverter is more efficient than an equivalent size 12 volt model as they use less amps to convert the voltage – we can calculate this using the equation: Power=Current x Voltage. Double the voltage means half the amps and this means less heat, better input regulation and losses are reduced across the system. 24 volt systems will need to be stepped-down to 12 volt for any of your existing wiring and as most batteries in Australia are 6 or 12 volts, you’ll need to invest in more batteries to ensure you’re getting the correct 24 volts.
GET THE RIGHT SIZE FOR YOU
With 12 and 24 volt inverters ranging from 100 Watts or less, right up to 6000 Watts plus, it’s important to choose the right size for your application. These days inverters are over 90% efficient, which may seem like a figure that won’t affect your power usage, but consider a 1000 Watt inverter at full power and there is a waste of around 100 Watts – at 12 volt that equates to over 8 Amps! In a 100 amp hour battery, just the wasted power could drain the battery to 50% charge in around 6 hours, so it’s not always a case of bigger equals better. Make a list of the appliances and devices you wish to run, consider which ones might be run at the same time and then calculate their total wattage. Another consideration must be made for the extra power that is needed on start-up of some devices, particularly those with an electric motor such as fridges or power tools.
REDARC POWER TIPS
Every inverter has a surge power rating that means it is able to produce extra power, for a short period of time (usually up to 15 seconds) so that a device can start, then fall back its usual power usage. Surge power is specific to each inverter so don’t just assume that because you’ve found the specifications for one particular model, that similar models will be the same. If the inverter experiences the extra voltage draw for too long it’ll shut down to protect its circuitry. In the same way low input voltage will also cause the unit to shut down to protect itself. To maximise the efficiency of your inverter be sure to mount it close to your battery, use adequate size cables and consider other energy solutions for lengthy activities like cooking where using an electric pan might be drawing a constant 100Amps – that’ll almost drain your batteries by the time dinner is ready!
EXAMPLES OF POWER USAGE
You’d be surprised just how much power some devices and appliances use. A quick look at the labels on products around your house and you’ll start to see what is and isn’t viable for use on the road!
MATCHING YOUR INVERTER TO YOUR SETUP
To correctly choose the inverter you need, tally up your appliance wattage, your usual usage and your battery supply – there’s no point choosing a larger inverter if it’ll discharge your batteries faster than you can top them up. For a safe rule, choose an inverter 25%- 50% larger than the total wattage of your appliances if you plan to use your laptop connected to a large TV to watch a movie, you’ll need 200 watts output – in this case a 300W inverter will offer an extra safety buffer as well as provide enough surge power to start both devices. But remember to consider battery usage, 200 watts of power at 12 volts equals around 16.7 amps, so don’t plan to watch a movie marathon as you could flatten a 120 amp hour battery to 50% capacity in three and a half hours!
For regular use in your vehicle to charge things like phones, cameras or laptops you can’t go past a portable inverter like the Waeco PerfectPower Can size inverter. With up to 150W of power it’ll easily charge your laptop, tablet, and camera or phone while you’re on the move!
• $40 to $100 for a portable inverter ranging from 100W to 200W
MODIFIED SINE WAVE
If you need a permanent long term solution, but don’t need to power sensitive
electronics then there’s no need to spend the extra money to get a Pure Sine Wave inverter. A Modified Sine Wave Inverter will take care of most, if not all, of your power needs and they won’t break the bank.
• $70 to $150 for a 150W to 300W inverter
• $100 to $200 for a 300W to 600W inverter
• $200 to $500 for a 600W to 1000W inverter
• $250 to $600 for a 1000W to 2000W inverter
Inverter Chargers really do offer the best of both worlds and being available in MSW and PSW versions there is a model that will suit every purpose. Inverter chargers integrate the whole electrical system together meaning once they are setup there is less hassle to keep your van batteries charged and your appliances running. If you rely on solar then the extra cost of an inverter charger isn’t necessary, however if you use a generator or powered sites often then it makes things much easier.
• $450 to $1600 for a 1000W modified sine wave inverter charger
• $600 to $2000 for a 1600W pure sine wave inverter charger
• $1000 to $2800 for a 2000W pure sine wave inverter charger
PURE SINE WAVE
For those who want the ultimate inverter that’ll power any device, a Pure Sine Wave model is ideal. Able to run all the electronic devices you can think of including medical equipment, the only down side to a Pure Sine Wave inverter is the bigger price tag.
• $140 to $500 for a 150 to 300W inverter
• $300 to $600 for a 300W to 600W inverter
• $400 to $720 for a 600W to 1000W inverter
• $500 to $1700 for an inverter in the range of 1000w to 2000W