Power Inverters

Power inverters are electrical devices designed to convert direct current (DC) to alternating current (AC). DC is the power that is produced by batteries and solar panels while Ac is the standard power needed to run electrical equipment. A power inverter does the opposite of a rectifier and is used in places and situations where AC power is not available.

Power inverters produce one of three types of power wave signals. Each signal represents a quality of power output. The first set of inverters made which are now obsolete produced a Square Wave signal. Square Wave signals produced power that was not reliable or consistent.

The second wave signal is the Modified Square Wave also known as the Modified Sine Wave. Modified Square Wave Inverters are the most popular and produce efficient stable power that can run most standard electrical equipment.

Pure Sine Wave inverters produce the most reliable and consistent power wave signal. This makes them the most expensive to acquire. Some equipment that are sensitive such as rechargeable tools and medical equipment require Pure Sine Wave inverters.

Power inverters come in different shapes and capacities. The conventional models are small rectangular boxes with an attached wire and jack that can be plugged into the cigarette lighter port on the dashboard of a car. Some models have jumper cables that can be connected directly to battery terminals. The box would normally have about two outlets to plug in your electrical equipment.

You could use a power inverter in your car or boat to power devices such as laptops, video games consoles, a small television or DVD player. They also come in handy in emergencies when there is a power outage. They are also helpful sources of energy on camping trips, beaches and parks where conventional electricity is not available.

Power inverter can also be used in areas with unstable power supply. The inverter is connected to batteries and the main electrical source. When there is an electrical power supply the system is designed to charge the batteries to store power and when there is a power outage the inverter draws DC current from the battery and converts it to AC to power the home.

The capacity of a power inverter would determine the type and number of devices it can be used to power. Models differ in wattage capacity and you need to be sure you a get an inverter that suits your needs. To calculate what the capacity you require you need to measure the wattage that your devices would draw and add another 50% to cover for spikes or peaks in the power draw. For example if you intend to power two devices each requiring 100 watts that would amount to 200 watts plus 50%. The recommended inverter you require should be a minimum of 300 watts.

The longer you use a power inverter the more energy is drawn from the battery. It is thus important to fully charge the battery and even to have a spare. The number and capacity of the devices you plug to the inverter also affects the rate of battery drain.

If you decide to use an inverter make sure that you get one with a capacity that suits your needs. If you are using a power inverter inside a car that is not running, it is advised that you start the engine every 10 to 15 minutes to prevent the battery from discharging. It is not advised to use adapters to plug more devices than the inverter is designed to carry. It is important to follow the owners manual as working with batteries could lead to injury and improper connection or use of an inverter could lead to electrocution.

Power Inverter FAQ

What is a power inverter?
A power inverter is a DC to AC inverter device that is capable of turning DC power, like the power found in batteries or the kind collected from solar panels, into AC power that is used to run everyday things in the home such as appliances, electronics, and even household lighting.

What is a power inverter used for?
A power inverter transfers your readily available DC power, like from a battery or other stored power source, and turns it into readily usable AC power on the go or at home on devices you would normally plug into a home electrical outlet.

How do I know what size of power inverter I will need to get for my home?
It is a good idea to add up the wattage used in the home normally by the amount of wattage used in each appliance and electrical item, lighting, etc., and then also give extra wattage for startups and occasional surges that many appliances tend to put out at times. So the amount of wattage all your electrical items give out plus some additional wattage for surges and startups should indicate a close enough measure of the size of power inverter DC to AC your home will need. Remember that having excess power is much better than having a brown out because you depleted all of your available power.

Where should batteries that connect to the inverter be stored?
The batteries that connect to your inverter should be kept in fairly close proximity to the power DC to AC inverter so that the cables can be short and run a clean and clear signal. Power inverters are not weatherproof and should be kept from getting wet. It should be kept dry like any other electronic device seeing as wetness will destroy your device and cause an unsafe situation. You should not allow your power inverter to get struck by lightning. Lightning will destroy it. Make sure to keep your power inverter away from any kind of generated heat or flammable source that can cause overheating and fires.

Is it better to have a modified sine wave power inverter or a pure sine wave power inverter?
It all depends on the conditions you will be using your power inverter in. Will it be on the go, in a vehicle perhaps? If so, a modified sine wave power inverter might be the better choice in this circumstance because modified sine wave power inverters are more portable and are lower priced than pure sine wave power inverters. Most devices do fine with modified sine wave power inverters. If your situation requires you to need a power DC to AC inverter daily in your home, like in the circumstance of using solar energy as a main source of power, you may want to consider a pure sine wave inverter DC to AC output. Pure sine wave power inverters are longer lasting, reliable, and their motors run at a cooler temperature which creates safer and more desirable regular running conditions. It is notable to mention that there are electronic devices that actually require pure sine wave power inverters to run properly. It might be a good idea to check with the manufacturer of the device in question if you are unsure.

What type of battery should I be using with my power inverter?
Deep cycle batteries are highly recommended and most often used with power inverters because they tend to maintain a consistent voltage more efficiently, are longer lasting than conventional batteries, they work well in extreme weather conditions, and they deliver a higher capability of amp surge than a conventional battery ever could carry.

Is it possible to use an extension cord with a power inverter?
It is possible to use an extension cord with your power inverter, but VAC extension cords shouldn't be run beyond 200 ft in any direction or you may suffer from an extreme signal loss.

Should a vehicle with a power inverter installed in it remain idle while using it to help maintain its battery charge during use?
Yes, most people allow their vehicles to remain idle while using power tools and other electronic equipment when they are running a power inverter off their vehicle's battery supply. It may be a good idea to check with your vehicle's manufacture to find out what kind of charge your alternator can handle on a consistent basis just to be sure.

How do I know how many batteries I will need to run my power inverter properly and efficiently?
The amount of batteries you will need to run your power inverter on properly and efficiently all depends on what you will be using your power inverter to supply power to. If your home runs solely on the bank of solar energy you collect and convert to AC power through your power converter, you may want to get a whole bank of batteries that will work together to meet your home energy needs. Adding 2 or more batteries will double or triple your output and length of power and so forth, depending on the amount of batteries you have in your power bank. If you only use a power inverter as a back up source of energy or partial source of energy, only 1 or 2 batteries should be a sufficient source of power for your power inverter to run properly and efficiently.

Can I run a microwave on a power inverter?
Yes, if you have dedicated ample wattage use solely towards the operation of the microwave. The wattage use that the microwave states are just its required wattage for operational use, not its actual wattage used when in operation. Power surges are very common in microwaves and they require extensive amounts of wattage to run regularly.

Are there appliances that are not compatible with power inverters?

There may be some small appliances that may get damaged or will not work properly with DC to AC inverters. Small rechargeable appliances can be damaged if they normally run on batteries but are able to be recharged through an AC outlet. It is a good idea to check if they carry a small nickel-cadmium battery before charging them on a power inverter. These types of appliances cannot run on a power inverter. They will actually get damaged if you plug them into a DC to AC inverter.

What is the best type of surface to set a power inverter on?

Your power inverter will do best and run most efficiently and safely on a flat, dry surface that is preferably indoors where it is away from extreme weather elements and exposure, and it should be placed within fairly close range of your battery supply to get a direct and clear signal.

What is the ideal temp to store a power inverter?
Keep your power inverter out of direct sunlight and kept at a storing temperature of between 50 degrees and 80 degrees Fahrenheit. You should also make sure your power inverter is getting proper ventilation to avoid issues with overheating.

What is a low voltage alarm?
Power inverters come with a low voltage alarm that sounds off ahead of time to make you aware when your DC power drains down below 10 volts. Once the low voltage alarm has sounded it will then begin to shut itself down to avoid completely draining your battery of power where it would be unable to restart.

Should a power inverter on a vehicle be stored under the vehicle’s hood?
No, a power inverter should never be installed under the hood of a vehicle because of many problems that would arise from this. Power inverters on vehicles should be installed in an area away from any source of heat or where they are sufficiently protected from susceptibility to acid corrosion or endangerment of becoming wet. Many people have their power inverters installed in a compartment on the back of their vehicle, and they run an extension hook up from that point to their vehicle's battery supply. Some people even add an extra battery to keep this type of connection running more continuous and efficiently.

Why do I sometimes hear a buzzing sound coming out of my audio appliances when I run them on my power inverter?
Some audio devices pick up a modified sine wave power inverter's electronic hum signal. These types of lower quality audio devices will operate noise free if you use a pure sine wave power inverter on such devices. A pure sine wave power inverter is very efficient in filtering out common-mode noises in audio devices.

If I use a computer printer in my home, which kind of printer will work more efficiently with my power inverter?
An ink jet printer will operate more efficiently and with less power usage than a laser printer. This makes an ink jet printer the more reliable and intelligent choice in homes that use a power inverter as their main power source.

What are the different types of power inverters available?

There are square power inverters, modified sine wave power inverters, and pure sine wave power inverters available. They are all available and convert DC power to AC power. The type that you will need to purchase depends on your own personal power needs.

Why would my power inverter turn itself off and allow a red light to come on while making a beeping noise?
Insufficient energy draw or bad connections can cause your power inverter to shut down. It does this as a safety mechanism to prevent unsafe conditions.

What are solar power inverters?

A solar inverter is a crucial element in a solar energy system. The solar power inverter is an electrical inverter that converts the direct current energy (DC) into alternating current (AC) for use either in a home or on an energy grid. The inverter is often the most expensive component of solar energy system.

Solar inverters are a critical components in solar power systems. In a solar energy system energy from the sun is gathered in photovoltaic cells (PV) that consist of semiconductor layers made of crystalline silicon or gallium arsenide. These layers are arranged in panels consisting of positive and negative layers. When the sun shines on the panels, light is absorbed and energy is transferred into the photovoltaic cell. Electrons in the light move from one layer to the other and produce an electric current. This current is direct current energy (DC). Depending on the type of system, it can either be stored for later use or sent directly to the inverter.

For regular consumer use, alternating current (AC) is required. The inverter works by running the direct current through two transistors that are rapidly turned on and off and feeding two sides of the transformer. In this way the direct current which runs in a direct line is converted into alternating current. Alternating current consists of a true sine wave (on an x-y graph a sine wave moves from zero up to a positive point then back down through zero to a corresponding negative point. Each of these cycles is called a hertz.) The current moves up and down in a smooth wave like motion consisting of 60 cycles or hertz per second.

Solar inverters can be grouped in three broad types:

Stand-alone inverters or off grid inverters do not tie into the utility grid and do not require anti-islanding protection. Stand-alone inverters are used in isolated systems where the DC energy is gathered directly from the photovoltaic cells or another source like a wind turbine.

Grid tie inverters work with a utility supplied sine wave. For safety reasons they are designed to shut down during a power failure.

Back up battery inverters are specialized inverters designed to draw energy from the battery, manage the battery charge through an on board charger and export excess energy to the power grid. This type of inverter requires anti-islanding protection. This prevents the inverter from continuing to function if the utility grid is shut down. Since 1999, any inverter listed to the UL standard of 1741 can be tied into the power grid without additional anti-islanding protection.

Read more power inverter FAQ.