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As occupants of a vehicle—both driving and riding—our list of plug-in gadgets is ever growing. Gotta charge your laptop on the way to the office? Need a charging port for that. What about that plug-in coffee mug to keep your morning fuel piping hot? Hmm, gotta find a plug for that too.
Thankfully, most vehicle manufacturers have heard our cries and are including multiple power ports in their vehicles, including USB, 12-volt cigarette lighter, and even AC outlets. While this is great, not all of us drive new cars with all of those bells and whistles. Or maybe you do and you want a few extra plug-in options. Whatever the scenario, buying a power inverter adds electrical ports to your vehicle for a plethora of things.
But which one should you get? To aid in your power inverter buying process, we put five of the top-rated options to the test. We analyzed each inverter through a range of parameters in our Gear Team gauntlet. Here's what we uncovered.
Our Top Picks
How We Tested Power Inverters
We tested power inverters as practically as we could, plugging in common devices to see how much juice each would deliver. We tried a variety of electronic accessories ranging from iPad chargers to a hair dryer and a blender. To get a sense of which power inverter works best for any given situation, we tested the following parameters:
Number of ports
Surge protection results
We assembled our notes and testing data to decide which power inverters were the best for certain situations. Our data contained both objective and subjective observations and, surprisingly, none of these units had the smaller USB-C ports that are used by a lot of the latest electronic devices. Here are our picks for the best power inverters.
SuperOne 150W Power Inverter
For a light-duty power inverter that does a little bit of everything, the SuperOne 150W is our pick. Featuring two USB, one AC, and two cigarette lighter–style ports, there's room for a host of different gadgets.
The cupholder design is nice, but only if you have the room to spare (a road-trip beverage is the priority, right?). During our device test, the SuperOne handled the phones, iPads, and battery chargers, and regulated our hair dryer to a low output without blowing any fuses.
It's rated for 150 watts, which might not sound like a whole lot but is enough for most electronic devices necessary for a pleasant family road trip. Because of its versatility, it's our pick for the Best Light-Duty Power Inverter.
Energizer 500W Power Inverter
If you need a power inverter for higher-draw devices, we recommend the Energizer 500W. With the ability to plug into your vehicle's cigarette-lighter port and connect directly to the battery, it offers a few more options.
There are four USB ports and two AC outlets to choose from, so there's room for everyone. In our device test, the Energizer was able to handle two iPhones, two iPads, and the battery charger, but blew the internal fuse when we tried to power on a blender.
To utilize the full 500-watt rating, you'll need to connect it directly to your vehicle's battery with the included alligator clamps. Because of the six plug options and internal protection, this is our pick for the Best Power Inverter for Higher-Draw Devices.
DeWalt 140W Power Inverter
If you just need a couple of charging ports, the DeWalt 140W is a great option. The inverter is built with durability in mind, featuring rubber grips and a thick power cord. This thing isn't going to break any time soon.
There's also a handy status light that burns blue when power is being supplied and red when a fault is detected. In our device test, the DeWalt survived a phone, iPad, and blender, but blew the internal fuse with the hair dryer.
We loved its rugged construction and the status light but wish it had more options for plug-ins. Regardless, it's an honorable mention and a fine choice.
Bestek 300W Power Inverter
While the Bestek 300W looks slick, it did fail our device test. It was able to power an iPhone, iPad, battery charger, and hair dryer for 5 seconds—until it popped our van's 20-amp fuse.
Is this the Bestek's fault? Not necessarily. It's rated for 300W (our van's circuit was rated for 240W) and goes to show that you need to check your vehicle's capacity if you want to avoid replacing a fuse all the time. Bestek says the internal fuse is rated at 40 amps—which seems really high compared to our vehicle's 20-amp fuse.
It's a solid power inverter that looks great, but be careful—it will pop your vehicle's fuse if too much load is demanded.
Duracell 800W High-Power Inverter
No, this isn't a supersized Duracell battery, but we do like the design. The Duracell 800W power inverter is a true brick, capable of producing up to 800 watts when directly connected to the battery. It's rated at 175 watts when connected to the cigarette-lighter port.
It's lacking in port options, with just one USB and two AC outlets. It also failed our device test, powering an iPhone, battery charger, and hair dryer—but blowing the vehicle's fuse. It should've blown its internal fuse before that but somehow didn't.
While there are definitely applications for larger devices connected to the battery, this inverter is just too unwieldy to keep and use regularly inside the vehicle.
How We Tested Power Inverters
We wanted to test power inverters in the same way most people would use them. The no-brainer test ended up being, "If I plug this in, will it work?" While this was the main parameter we wanted to try, we included other valuable data in our test results. Gear Team Tester Katherine lent her dependable 2001 Ford E-150—affectionately known as Rhonda—for this test, and it was a true vehicular champ.
For our main supported devices test, we plugged in various gizmos starting at the lowest wattage and working our way up. Our first devices were iPhone and iPad chargers, then we progressed through a Milwaukee battery charger, a blender, a dual-action polisher, and finally, a hair dryer. Here's the power draw for each device we measured with a Kill-A-Watt:
iPhone charger: 14 watts
iPad charger: 14 watts
Milwaukee battery charger: 90 watts
Blender: 290 watts at peak, 125 watts continuous
Polisher: 260 watts at peak
Hair Dryer: 547 watts at peak
We stacked these devices in ascending watt-usage order until the internal power inverter fuse popped or, in two cases, the 20-amp vehicle fuse blew. We then took notes on how much each inverter could take and which fuse blew first for our surge protection test.
We counted the number of USB and AC ports each inverter had, along with the weight via a mail scale. We then measured the power-cord length from the base of the inverter to the end of the plug. And finally, we took notes on the usability of each inverter.
Things to Consider When Shopping for a Power Inverter
There are a whole bunch of different power inverters out there, each with different wattage ratings. Which one do you get? To make your power-inverter party run smoothly, here are some things to consider.
Wattage rating: This might be the most important factor when it comes to buying a power inverter. All it takes is some simple math to know if an inverter can handle what you want to plug in. Multiply the voltage (5 volts for USB, 12 volts for cigarette lighter, and 120 volts for an AC) by the amperage of your device to get the wattage. Compare that to the wattage rating of your power inverter, and that'll tell you if it can handle the draw.
Another thing to check is your vehicle's fuse rating for the 12-volt port—the fuse on our test van was 20 amps. By doing the math, that circuit can handle 240 watts. Any draw above that will pop the fuse.
The easy solution is to just install a larger fuse, right? Wrong. That entire circuit, including the size of the wiring, is rated for no more than 20 amps. If you demand more, you run the risk of starting an electrical fire. If you need to run a high-wattage device, consider getting a power inverter that hooks directly to the vehicle battery—which can handle a lot more juice than the 12-volt cigarette lighter.
Number of outlets: Check to see how many USB and AC outlets the power inverter offers. They're all a bit different, and it's important to double-check that an inverter has the ability to handle what you need.
Power-cord length: If you need devices to reach the inverter from the back seat, it's important to take the power-cord length into consideration. There's nothing worse than taut cords reaching from every seat like a spider's web.
Heat: These little devices work hard to put out the power you need. A side effect of this is heat, and the devices can get piping hot if powered on for long periods of time. Keep that in mind, and make sure it doesn't melt delicate surfaces or those road-trip chocolate chip cookies.
What does a power inverter do?
In short, a power inverter changes 12-volt direct current (DC) from your vehicle's cigarette-lighter port to 120-volt alternating current (AC). The devices you plug into wall outlets use AC, although some of them, such as phone chargers, convert that back to DC.
Do power inverters drain your vehicle's battery?
Yes, and it's important to keep an eye on the battery charge level or keep the vehicle running. Some power inverters feature an audible "low-power" beep or shut off when low power is sensed. If you're looking at getting a larger power inverter that runs off the battery, it's important to verify your vehicle's electrical system can handle the strain. Consulting a professional is a safe bet.
How long will it take a power inverter to drain a car battery?
If you use a smaller power inverter for a low draw like charging your laptop, you can expect to get between 30 and 60 minutes of power before your vehicle's battery dies. This, of course, depends on the draw and state of the battery. It's best just to leave the vehicle running.
What kinds of things can I use in a power inverter?
It depends on the wattage rating of said power inverter, but typical devices include phone and laptop chargers, small televisions, and gaming systems. Larger power inverters are capable of powering just about anything—your vehicle's electrical system needs to be significantly upgraded, though.
What do you do if the power inverter's fuse blows?
Most power inverters come with some extra fuses, and they're generally easy enough to replace. Simply unscrew the end of the 12-volt plug adapter, remove the cylindrical fuse, drop a new one in, retighten the end, and you're good to go.
What do you do if the vehicle's fuse blows?
If your vehicle's 12-volt cigarette-lighter fuse blows, check the owner's manual for the fuse locations—there are typically multiple fuse boxes on any given model. Find the fuse for that circuit, and pull out the old fuse with a pair of needle-nose pliers. Hold it up to the light and look for a break in the metal portion. It might even look burnt. Replace it with a fuse of the same amperage rating, and you're good to go.
Why Trust Us?
Hearst Autos combines the talent, resources, and expertise of three of the largest, most influential automotive publications in the world. The Gear Team has tested a wide variety of automotive products, parts, accessories, and gear, such as GPS trackers for cars, OBD2 scanners, and electric car chargers. We get our hands on each and every product we test. Most are purchased; some are supplied by manufacturers.
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