Your car’s electric system runs on DC. Your laptop charger craves AC. What do you do? You grab a power inverter, which allows standard electronics and appliances to run off your car battery.
There’s a smorgasbord of various designs and tiers for converters, from single-outlet accessories that plug into a cigarette lighter adapter and stow away in the glove compartment, to massive permanently-installed bricks drawing enough power directly from the engine’s alternator to run TVs or power tools. Most users won’t need anything particularly elaborate, so we’ll begin our selections with a modest step up from a basic inverter you can grab at any truck stop.
For anything more than a very light load (like charging a laptop or handheld electronics) you’ll need to take a moment to really assess the power draw requirements of your equipment and the electrical output of your car’s battery to make sure the inverter you choose can handle your specific situation. Plugging in to the 12-volt cigarette lighter is enough to charge a laptop or few pieces of car stereo equipment, but anything above 200 watts or so will need to be wired either to the car battery or the fuse box. If you don’t know what you’re doing, find someone who does, or simply pay a car mechanic to install your inverter permanently. Messing around with this level of electricity can seriously injure or kill you.
Inverters output electricity at 120 volts, the same as a standard home power outlet. To determine how many watts you need, here’s a few quick examples of running power draw for electrical appliances. Some, like power tools, need a higher “peak” watt rating to start; inverters can usually handle 1.5-2 times their standard watt rating for peak bursts.
- High-speed phone charger: ~15 watts
- Laptop charger: 45-90 watts
- Game console: ~150 watts
- Television: 80-400 watts, depending on size
- Mini-fridge: ~40 watts
- Microwave: 900-1500 watts
- Power saw: 1200 watts
- Electric air compressor: 2000 watts
If you happen to overload your inverter, the internal fuse will trip and it will stop working before it damages itself. Some of the more robust models include user-serviceable fuses that you can replace.
Best Cigarette Lighter Inverter: Bestek 200-Watt Cup Portable ($30)
If all you want is a convenient way to charge up some portable electronics in a car with no factory installed outlet, this is it. This handy little design sits snugly in your car’s cup holder, presenting two AC outlets with a maximum of 200 watts of electricity. It also has two USB charging ports with 4.5 amps each (enough for standard-speed charging) and a pass-through cigarette lighter port, so you can keep your regular charger active so you can keep using your GPS unit—or, um, light cigarettes, I guess.
There’s a handy power button so you don’t need to unplug it when you turn off your engine, and the top closes down to protect the ports when not in use. This design is excellent if you’re planning on travelling in someone else’s car as a passenger, and want to make sure there’s plenty of charge to go around. Just don’t try to pour your coffee in it.
Best Budget Inverter: Potek 750-Watt ($46)
This budget option is a great pick if you need some flexibility, or aren’t sure you’re ready for a permanent installation. When plugged into a cigarette lighter port, it can output 150 watts to two AC outlets with two USB charging ports as a bonus. When you’re ready for more juice, you can connect the power clips directly to your car’s battery for 750 watts, enough to power a game console and TV or high-end car audio.
Though the combined package is under $50, it includes a wattage LCD readout and spare fuses if one of the safety fuses should trip. If you want to run more powerful equipment without stopping and popping the hood, you can plug standard battery cables into the rear-mounted ports for a permanent installation.
Best Overall Inverter: Krieger KR1500 1500-Watt ($140)
If you’re ready to step up to a permanent, high-quality solution, Krieger’s 1500-watt offering is our pick. This heavy-duty model is designed to be fixed in the car or truck interior, with an included remote power switch you can mount to the dashboard for easily enabling and disabling of the power draw.
Cables are included for a direct battery installation, along with a spare user-replaceable cable fuse. The LCD display can cycle between electricity input and output, as well as total car battery level, allowing you to keep a close eye on your car’s electrical system. Similar KR models are available at different ratings: $65 for the smaller 1100-watt version, and $190, $300, and $350 for the 2000-watt, 3000-watt, and 4000-watt versions, respectively, all of which have the same features.
Best High-Power Inverter: AIMS Power Compact 5000-Watt ($370)
If you need enough electricity to run IBM Watson in your pickup bed, you’ll need to drop some serious cash on your inverter. The AIMS Power series is about as high as you can go without reaching into the much more expensive pure sine wave industrial market. The 5000-watt version should be powerful enough to run multiple power tools at once, and there are even higher watt models in the series if you need it (and your budget can accommodate it).
This model foregoes an LCD readout and USB ports for four AC outlets, though it still has an LED display for output and car battery levels. A direct hard wire connection allows compatible tools to pull all 5000 watts at once. There’s no included installation hardware, but for an investment like this, it’s probably best to get it professionally mounted and connected anyway. It’s compatible with a standard dash-mount remote power switch for easy activation and deactivation from the driver’s seat.