Power Inverter Basics

What does a power inverter do?

A power inverter is used to convert DC power (direct current - the power produced and stored by batteries and solar panels), to AC power (alternating current - standard power used to run regular household lights, electronics, appliances, etc.), and are used in places where AC is not available, or when the amount of AC power available on a site is limited and/or inadequate.

What is the difference between Modified Sine Wave Inverters and Pure Sine Wave Inverters?

Modified Sine Wave Inverters are simple devices that are able to convert DC power produced from your vehicle power system, into useable AC power.  The AC power output from a Modified Sine Wave Inverter can run most standard electrical devices and equipment.  Modified sine wave power inverters are usually more portable and lower priced than pure sine wave power inverters.
Pure Sine Wave Inverters produce the most reliable and consistent power wave signal, ideal for crucial applications such as medical equipment, essential rechargeable tools or situations such as using solar energy as a main source of power.  Pure sine wave power inverters are longer lasting and run at a cooler temperature which creates safer and more reliable running conditions. 


Power inverters are usually 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 inverter box would normally have about two outlets for you to plug in your electrical devices or equipment.

Common applications are using the inverter in your car or boat to power small electronic devices such as laptops, video games consoles, a small television or DVD player.  They are also helpful sources of power for outdoor activities or for emergency backup in the case of an unstable power supply or power outages.

Never leave an inverter connected to a line where other power (Vac) may feed into inverter.  It doesn’t matter if inverter is on or off

Using inverters in moist areas is a common cause for their drivers to burn out.  Even an outdoor extension cord that was laying in a puddle a day previously, may have enough moisture to burn out the drivers of the inverter.  Tip: if using inverter in rain one day, allow cords that may have gotten wet to dry a few days before using in inverter again

Always prevent foreign objects from entering inverter through the vent or fan openings

Keep cables between inverter and batteries as short as possible.  This will help your batteries perform their best

Don’t over tighten nuts to battery or inverter, but do check them occasionally.

If the cables between your battery and inverter get hot while under heavy load, then you should consider using heavier cables

Both “hot” and “neutral” lines are hot on inverters.  Do not ground the neutral line.  Do not connect neutral to panels that may have neutral grounded.

Using a 12Vdc inverter, your input Voltage should never exceed 15Vdc or the inverter may shut down with Over Temp and you should hear an audible beep

When selecting an inverter, try to buy one that will stay in the continuous operating range and do not rely on advertised surges

Standard 110Vac outlets are typically rated at 1500W or 15Amps.  This is for heat dissipation through the outlet and is not a limitation of the inverter

If cables need to be run, it is best to keep inverter as close as possible to batteries.  Use extension cords on the output side (Vac output) rather than extending the Vdc cables.  Tip:  Contractors often need to mount the inverter in the back of their trucks.  In a case like this it would be best to mount a secondary battery near the inverter and wire it to the primary truck battery

Ac plug testers do not work with inverters.  You would see an open ground

Be aware of lighting storms.  If struck, inverter would go to a permanent Over load state and may even smoke

Vac extension cords should not exceed 200 feet or you will have signal loss

Inverters emit RF and may cause interference.  This is noticeable in AM radio and often monitors and computer mice