Skip the 12-Volt Car Port. There’s a Faster Way to Charge Your Power Station.

Let us tell you about what an alternator charger can do.

Road warriors and overlanders know all too well that the 12-volt port in a car or truck recharges large devices slowly. Case in point: a power station. Most come with a 12-volt adapter for this purpose, but even a midsize model can take nearly 13 hours to recharge this way.

The solution to speed up the process is installing an alternator charger. They deliver a lot more power while you’re on the road and have the added benefit of reverse charging a dead starter battery using a power station.

Recommended Alternator Chargers

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Anker Anker Solix 800-Watt Alternator Charger
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Alternator Charger Basics

Alternator chargers only work with cars that have a 12- or 24-volt battery (i.e., the starter battery). Essentially, an alternator charger is an intermediate controller that connects the car’s battery to your power station, drawing power from the car at a higher voltage than a 12-volt connection. The term alternator might be misleading because the primary connection to the car is via the battery, not the engine’s alternator.

Alternator chargers tend to come in models that output 500 watts or up to 800 watts, but not all engine alternators support the higher amount, particularly older or smaller economy cars. Any engine alternator that produces less than 60 amps should only be paired with an alternator charger that outputs 500 watts or less (or is set to do so automatically or manually).

Another key point: Always keep your car running while using an alternator charger. Not doing so is a sure way to drain your battery, especially in hybrids, which tend to have smaller-sized 12-volt starter batteries.

Installation Isn’t All That Hard

While it’s always a good idea to leave any aftermarket car installation up to a professional, installing an alternator charger is pretty simple. Just keep your Most aren’t much larger than a medium-sized book and have mounting brackets on the back that affix to the back of the rear seat, the trunk, or somewhere out of the way in a hatchback. Wherever you choose to install it, however, make sure it’s in a ventilated area, as these devices can get hot when in use.

The trickiest part of the installation is running the wire from the controller to the battery. The main cable splits into positive and negative wires that connect to the 12-volt battery’s positive and negative terminals (you can also connect the negative wire to any bolt that is attached to the frame of the car).

Since most batteries are near the engine under the hood, you’ll need to fish that wire from the interior of the car via the firewall port, which is typically located under the driver’s-side dashboard area. Every car is different, so always consult your manual on where that is located.

Trevor Raab
The connection to the car is as simple as connecting the negative and positive cables to the starter battery. In this case, the battery is located in the trunk area of a Lexus Hybrid.

From there, run the cable to the controller. If you want the cable to be out of sight, locate the wire channels in the car. Often, these are found by pulling up the plastic thresholds along the edge of the floor of the vehicle, which you can see clearly when you open the door. Then, simply connect that cable to the controller, connect the power station to the controller, and you’ll be up and running.

Trevor Raab
Though each brand would prefer you use their charger to power their own stations, since most use a standard DC input (the same one a solar panel connects to), you can pretty much recharge any power station.

Special Considerations for Hybrids

Anyone who buys a hybrid is familiar with the learning experience that comes with locating the 12-volt battery, since its location varies depending on the car make and model. Often, it’s somewhere in the back, accessible from a panel in the trunk or hatchback area. Sometimes they’re inconveniently located beneath the rear seat.

Regardless, the connection process is the same, using the positive and negative terminals, but how you fish the cable to the controller varies. Something you must also do is verify that your hybrid vehicle can handle the continuous draw of the alternator charger. The good news is that most can, supporting 100 to 120 volts, which is compatible with both 500- and 800-watt alternator chargers.

What About Electric Vehicles?

Since these types of cars don’t have 12- or 24-volt starter batteries, alternator chargers can’t be used with them, so you’ll only have the 12-volt port to rely on; however, some electric vehicles feature built-in 120-volt or 240-volt AC household outlets and can output higher voltage (sometimes referred to as a Vehicle-to-Load [V2L] option). These can work to recharge your power station at a faster rate than 12-volt.

Dos and Don’ts of Using Alternator Chargers

Connecting any third-party device to your starter battery is outside of what the vehicle is designed to do. An alternator charger draws a lot more power than a car typically demands while operating, so be careful not to overload the system. Some things to keep in mind:

• Don’t use the alternator charger while running a lot of other items that tax the electrical system, like recharging or powering other devices from the 12-volt ports or running the air conditioner on high.
• Avoid using the alternator charger while idling. While the alternator charger will work, an idling engine doesn’t deliver enough mechanical energy to the starter battery, and you risk the possibility of running it too low, which puts stress on the battery and could deplete it.
• If you have a longer drive, lower the output. If you’re going to be on the road for many hours and have an alternator charger that allows you to vary the amount of power it draws, set it to something lower. For example, this EcoFlow charger can output up to 800 watts, but you can set it to 500 watts. It may take just under double the time to charge your station, but it puts less stress on the car’s electrical system. If you have a long drive, you’ll probably have the time to perform a slower charge.

Editor-Recommended Power Stations

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David Dritsas
Reviews Editor

David is a Reviews Editor for Hearst’s Enthusiast Group, contributing to Popular Mechanics, Runner’s World, Bicycling, Best Products, and Biography. He has over 25 years of experience writing about and reviewing consumer electronics, kitchen appliances, DIY products, outdoor gear, and more. He also spent years covering the ever-changing world of online retail. To relax, he loves experimenting with new recipes, tweaking his smart home setup, and spending time outdoors on his bike or camping.