An inverter is an electronic device that takes a DC input and converts it into an AC output. Since car batteries provide DC voltage, and most consumer electronics work on AC, inverters are useful for using laptops and other devices on the road. However, there are some vital constraints to keep in mind whenever you use an inverter in your car. Factors like the capacity of the car battery, rated output of the alternator, and output wattage of the inverter can all play a part in determining which devices can be plugged in and used.
Anyone who spends a lot of time on the road can benefit from some type of inverter. These devices are especially useful on long road trips, for camping, people who travel for business, over-the-road truck drivers, and other similar applications.
Some devices, like cellular phones and laptops, can be used with 12v attachments that plug directly into a cigarette lighter or accessory jacks. However, any electronic device that requires an AC input calls for an inverter. Some devices that you can run off a car inverter include:
DVD and Bluray players
There are a number of different types of inverters, but the two main types that you’ll find in automotive applications are:
Modified sine wave
These inverters are the more affordable of the two. They produce a “modified sine wave” that’s perfectly fine for most consumer electronics, so they work well in a lot of different applications.
Pure sine wave
These tend to be more expensive, but they produce a sine wave that is much closer to the AC power available from the power outlets in your home. Some devices, like uninterruptible power supplies, may fail to work properly without a steady, pure sine wave, but most consumer electronics will work just fine without one. If you’re concerned, you should check with the manufacturer of your device before investing in an expensive pure sine wave inverter.
In order to work, an inverter has to be hooked up to the car battery in some way. Some of the most common configurations include:
direct to battery
12v accessory socket
The easiest way to hook an inverter up is to simply plug it into the cigarette lighter or another 12v accessory socket, but there are some limitations to that type of setup. Since there may be other components hooked up to the cigarette lighter or accessory circuit, there is an inherent limitation on what type of devices can be hooked up to the inverter. Inverters that are connected like that are generally limited to a 5 or 10 amp draw.
In heavier duty applications, the inverter needs to be connected to the fuse panel or directly to the battery. Some fuse panels have empty slots that an inverter can be wired into, which will provide a dedicated circuit to the device. In other cases, the inverter can be connected directly to the battery with an in-line fuse. In either case, it is vital to use some type of fuse to avoid a potentially hazardous situation.
Since most cars and trucks aren’t really designed with inverters in mind, it’s important to avoid overtaxing the system. One vital factor to consider is the capacity of the battery. If an inverter is used when the vehicle isn’t running, it will tend to rapidly deplete the battery. Some trucks have extra space under the hood for an additional battery, which can help reduce the impact of using an inverter when the vehicle isn’t running, but that isn’t always an option.
While using an inverter when the vehicle is running will allow the alternator to keep the battery topped up, it’s also vital to avoid overstressing the alternator. Since alternators are typically designed to provide enough power to run all of the electronics in a vehicle and keep the battery charged, they may not have enough additional capacity to run a powerful inverter. The best way to avoid a problem in this area is to check into the rated output of your alternator and then buy an appropriate inverter.
There are some steps to wire a Car Inverter to a Car Battery:
Drill a one-quarter to one-third inch opening in the section of the firewall of your vehicle which runs from the upper left side of the engine compartment to the area immediately below the passenger-side glove compartment. Do not drill into the glove compartment unless you intend to locate the inverter therein.
Set a grommet of appropriate size in the hole.
Pull the red fused wire from the engine compartment side through the hole using a wire coat hanger or similar tool by attaching the tip of the tool to the end of the red wire with duct tape and pushing it through the hole. Make certain that the fuse compartment of the red wire remains on the engine compartment side of the fire wall. Remove the fuse from the fuse holder.
Pop open the rocker panels on the floor of the front passenger side and tuck the red wire underneath. Reattach the rocker panels. Run the red wire out of the rear of the rocker panel and under the passenger seat.
Mount the inverter under the passenger seat with the AC sockets facing to the rear of the vehicle. If permanently mounting the inverter, it may be necessary to remove the front passenger seat. After removing the seat, drill mounting holes into the floor of the vehicle and attach the inverter using metal screws. Attach the red and black wires to the red and black posts on the inverter. If the inverter has a chassis ground lug nut, attach a short length of black wire from there to one of the metal mounting screws attached to the chassis. Attach the black wire running from the black post next to the red post to any grounded bolt or screw going into the vehicle chassis. This can be one of the screws holding the passenger seat to the floor of the vehicle.
Attach the red wire in the engine compartment to the positive post of your car battery. Insert the fuse into the holder and turn on the inverter. Test the inverter with a volt/ohm meter or small appliance.