A MAINS POWER INVERTER ALLOWS YOU TO RUN YOUR 240V APPLIANCES FROM YOUR BATTERY BANK. WE’LL SHOW YOU HOW TO CHOOSE THE RIGHT INVERTER.
WHAT IS A POWER INVERTER, AND WHY DO YOU NEED ONE?
A power inverter takes the 12V or 24V direct current (DC) power from your battery bank, and converts it to 240V and alternating current (AC). They essentially emulate the mains power you have at home, however it’s not precisely the same, so there’s a few key considerations to make when choosing the right inverter.
INVERTER TYPE – PURE SINEWAVE VS MODIFIED SINEWAVE
There are a few ways to create the alternating current (AC) power from your batteries. The most common are called Modified Sinewave, and Pure Sinewave. The difference between the two is how close it approximates or matches the regular mains power you have at home. While some appliance can accept a rough approximation (modified sinewave), not all appliances can. Pure Sinewave inverters are generally also more efficient, so you get more usable power from your batteries.
Most of you will remember what a sinewave is from high school mathematics. Even if you don’t, it doesn’t really matter. The graphic above provides most of what you need to know. At the top of each curve, you have maximum voltage. At the bottom you have maximum reverse voltage. This oscillation occures 50 times a second (50Hz) for mains power. A Pure Sinewave (sometimes referred to as True Sinewave) inverter provides a very close approximation to this true sinewave which is found in your mains power at home. With a Pure Sinewave inverter, you can run just about anything within the maximum power limits of the inverter, without fuss.
Modified Sinewave inverters have a more crude approximation of mains power. This means that while many devices will run perfectly fine, some with sensitive electronics may struggle.
Consider what you’re going to run from your inverter, and select the model which easily covers your required power with room to spare. All mains appliances have power ratings on them, so it’s easy to determine how much power you’re likely to use.
Some sensitive equipment may switch on, but not operate correctly when using a Modified Sinewave inverter. We recommend using a Pure Sinewave inverter for anything with small electronics such as computers.
Some appliances such as those with motors inside (fridges, washing machines for instance) draw a massive amount of power for a fraction of a second when they first switch on. This surge current may overload the inverter. We provide surge current ratings for our inverters which cater for this initial startup current, however some appliances will draw many multiples of their operating power for that fraction of a second.
At home, this is of little consequence. Your circuit breakers in your home naturally handle this, and it’s rarely an issue with the general power grid. However take this to an inverter and it may not work at all.
BATTERY CHARGE CONTROLLERS
Some inverters feature solar battery chargers built in, or have the ability to switch between power sources (eg battery and solar) to make the most of your systems when there’s available power. If you’re mixing power sources, or are free camping regularly, this may be a useful feature for you. However a standalone charge controller may have better functionality for this purpose.
USB POWER OUTPUT
Let’s face it, USB power is in fairly high demand! So you’ll often find USB outlets on inverters to provide you with a great USB power source. This avoids having to have yet another power adaptor in the mix when you’re using your inverter, but want to say, charge your smartphone too.
Some models feature remote control operation and monitoring. This is particularly useful for larger models (which are more likely to have this functionality anyway) where you have it installed somewhere other than the appliances you wish to run.
IT’S JUST AS DANGEROUS AS YOUR HOUSE POWER
Just because the power comes from batteries, doesn’t mean it has less lethal potenial than the mains power in your home. While they’re perfectly safe to use with due care, the mains side in particular should be treated with the same respect and consideration as you would do with your mains points at home. Keep children, metal objects etc clear, and use general common sense.