Best Car Battery Chargers and Maintainers for 2023, Tested

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These car battery chargers and maintainers are the antidote to the dreaded click of a lifeless ignition.

As with many modern conveniences, a vehicle's health hinges on its power source. Battery maintenance is an accessible skill regardless of your experience level. It's also arguably one of the most important pieces of vehicle maintenance since, according to AAA, taking care of your battery health can help prevent many instances where you would need a costly tow.

In addition to routine battery upkeep, leaving a car to sit for an extended stretch practically guarantees you a lifeless battery. So, whether your goal is to dodge a towing hassle or ensure your summer ride fires up without a hitch after hibernation, it's important to take proactive steps toward caring for your battery. Why not start by investing a little effort and money into a car battery charger and maintainer, potentially saving you from financial strain down the line?

Not all battery chargers and maintainers are created equal. Before you decide which one to buy, here are some important factors to keep in mind.

While most chargers on the market are also maintainers, you should know the difference in the modes.

Charging a battery refers to the process of charging a partially discharged battery to regain the battery's voltage. Charging is usually done with higher amperage and is meant to charge the battery quickly and to full health.

Maintaining a battery refers to a low and steady trickle of electrical current to an already charged battery. Batteries, especially over time, lose their charge due to their natural chemical processes. The maintainer function detects and counteracts the loss with a small amount of amperage to top up the battery without overcharging.

We recommend you purchase a product that both charges and maintains. Most products on the market (including all that we tested) will detect the voltage and switch to maintenance mode on their own. But if you purchase a different product than we tested, ensure they will automatically switch to maintenance mode. Otherwise, you risk overcharging.

You'll encounter various battery types in the current market, such as lead-acid, AGM, and gel. It's important to ensure your charger is compatible with your battery type. To confirm your battery type, you may have to look at the side or top of the battery.

Amperage refers to the strength of an electric current and is often used to gauge the charging capacity. A higher current leads to faster charging. So if speed is a major consideration, opt for a higher amperage.

You'll need an external power source to charge your battery. When making your choice for purchase, note your available power sources to confirm the cord can reach from your intended 120-volt wall outlet to the battery terminals. For our testing, we measured the length from the ends of the alligator clamps to the 120-volt plug.

Determining the effectiveness of a charger can be clear as mud, given the sheer amount of variables—from amperage to battery type, battery health, and state of charge. For our test, we steered toward a more subjective test of user experience and evaluated the following parameters:

Here are the results of our test of some of the top battery chargers and maintainers on the market.

The NOCO Genius 1 belongs to a broader NOCO Genius line of products. The Genius 1 employs a lower 1.0-amp setting to begin a slow, steady charge. It's designed to work with the gamut of battery options—regular lead-acid, AGM, and lithium. Navigating the mode selection button provided a satisfying tactile feel when cycling through options. The bright white LED display made setup a breeze. And once the battery began charging, the pulsing red light indicating charging was underway added a hypnotic quality.

NOCO is a reputable company known for its smart charging features, such as integrated thermal sensors and desulfation modes, designed to prolong your battery's life. It's worth noting, however, that while these modes are reportedly integrated, their activation was not visible during our tests. So, sure, the charger doesn't display the intricate processes at play, but we don't think that's a problem. NOCO seems focused on delivering an effective, user-friendly charger, and to that end, the company nailed it with the Genius 1.

The Schumacher SC1280 is a beefy, cutting-edge battery charger. Blowing all the competitors out of the water with 15.0-amp rapid charging, this massive current will quickly bring your battery back to usable health—if you can wait patiently for the initial desulfation mode.

Of all the chargers we tested, the Schumacher distinguishes itself from the others with its LED display, rather than just indicator lights. The display provides an array of information we were not given with other chargers, including voltage, state of charge, and SULF (desulfation) mode.One thing we couldn't look away from was the sound level. Do you know the sound your computer makes when it gets too hot and the fans roar? That's the sound the Schumacher makes all the time. An editor passed by during testing without seeing the charger and asked, "Is that a Schumacher? My dad has one. They're loud." Despite this, we reckon the charger's operational sound does not pose a huge inconvenience, given you don't tend to linger around your chargers for too long.

If you're looking for a reliable and foolproof charger, Battery Tender is well established in the charging game. For its 3.0-amp model, we struggled to find any flaws other than some users may find the LED lights a little dim.

Otherwise, in terms of its operation, the Battery Tender uses a single button to toggle between 6- and 12-volt. Once a selection is made, you set it and forget it. It's that straightforward. This model doesn't offer extravagant features, but we commend Battery Tender for adhering to the essentials, especially in a market where products can become overly complex. Frankly, most folks are looking for a dependable, easy-to-operate battery charger, and we think the 3.0-amp Battery Tender has that down pat.

To include those in the realm of powersports, we tested the Battery Tender Junior. The Junior model caters to 12-volt battery types, including lead-acid, AGM, and gel batteries. Its 0.75-amp charging capability is most compatible with charging and maintaining motorsport batteries like ATVs, boats, motorcycles, and even lawnmowers.

We hooked the Junior up to senior testing editor David Beard's 12-volt gel ATV battery, which took no setup beyond clamping the alligator clips to the battery posts. After connection, a simple dual-color LED indicator uses red and green hues to convey the operational state of the Junior.

This is where the Battery Tender products shine the greatest: the simplicity of their setup process. The ease of use for both products is a notable advantage, particularly for those who may harbor reservations about electrical systems.

If your vehicle will be parked away from a conventional power source, consider harnessing the sun instead with the Sun Energise 10-watt solar panel. The Sun Energise is a mobile charging solution compatible with 6- and 12-volt vehicle and powersports batteries. Maintenance mode is run through a Maximum Power Point Tracking (MMPT) charge controller. The MMPT boosts efficiency and ensures a sustained charge without the chance of committing the cardinal sin of overcharging the battery.

Designed to be used inside or outside of your car, the Sun Energise features four suction cups for windshield application, which can be mounted to either side of the panel for various configurations. A notable highlight is its ability to charge your battery via the 12-volt port within your vehicle. However, not all vehicle models' 12-volt adaptors function when the ignition is off. For those vehicles, you'll have to use the supplied alligator clips or, alternatively, you can opt to hardwire the panel using the additional set of power and ground cables provided.

Naturally, the prime limitation of Sun Energise is its reliance on sunlight. While our testing left us impressed with the power capabilities of the charger, we recommend using it as a reliable backup rather than your sole charging provider.

The amount of time it takes to charge a car battery depends on many factors—so many that we couldn't realistically measure charging times and get fair, objective results to compare. Instead, we assessed each charger's features and ease of use over two days. Unboxing and taking notes along the way, we were curious about how each product differed in its setup, complexities, and behavior.

However, no matter how you cut it, you can't test chargers without a couple of batteries. For the testing batteries, we visited our friends at Town and Country Auto Parts, where they graciously allowed us to raid their core charge batteries, searching for batteries over 10 volts and at least 50 percent health. After pulling six batteries, we returned them to Gear Team HQ, cleaned and serviced each battery, and prepared for the test.

We unboxed the unit for each product, reading through their user manuals to note features, modes of operation, and battery compatibility. Next, we attached our batteries to charge, assessing the ease of use and setup. Lastly, we observed each charger's behavior, taking note of sounds, displays, and any information communicated by each device in the charging process.

Always read the instruction manual before setting up any battery charger or maintainer. Here are some basic guidelines to follow:

Prioritize SafetyAlways ensure you're in a well-ventilated area, and consider wearing protective eyewear.Prepare the BatteryIf your battery displays signs of corrosion, clean and service it before hooking up any charger or maintainer. This means cleaning the terminals and filling the battery cells with distilled water (if applicable).Set Up the ChargerOnce you've plugged in the charger, it's time to configure the appropriate settings for your battery. Select battery type and appropriate voltage.Connect the Leads to the BatteryThis applies to all battery-power procedures, whether using a battery charger, a jump pack, jumper cables, or simply removing your battery from your vehicle.To CONNECT: Positive (red) FIRST, Negative (black) SECOND

To DISCONNECT: Negative (black) FIRST, Positive (red) SECOND

A car battery charger is designed to recharge a vehicle's battery back to a healthy state, whereas a maintainer detects and optimizes a battery's state of charge.

No, but they are very similar. The main difference is that a trickle charger will continue to charge even after the battery is fully healthy, which can result in overcharging. If you use a trickle charger, you must monitor and disconnect the battery at the correct time.

How long it takes to charge your battery depends on many factors, such as the initial level of charge, battery capacity, and the amperage of your charger. However, if your battery is at a decent level of health, you can expect a full charge between four and 18 hours.

No, compatibility varies. Determine your battery type (lead-acid, AGM, or gel) and then select a suitable battery charger for that specific type.

Yes, there are chargers that cost more and feature jump-starting functions, but we didn't test any of those this time around. Need a quick jump? Try one of these jump packs.

To begin charging, start by attaching the positive side of your battery to the positive lead (red). Next, connect the negative side to the negative lead (black). For disconnection, follows the same steps in reverse.

You can, but exercise extreme caution. Before proceeding, thoroughly research the auxiliary battery. Be particularly cautious around components with bright orange cables as they indicate high voltage, which can be deadly. In short, prioritize safety.

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 garage flooring, catalytic converter anti-theft devices, and foam cannons. We get our hands on each and every product we test. Most are purchased; some are supplied by manufacturers.

Hearst Autos doesn't need to game algorithms for traffic or promote lousy products to earn a buck. Instead, we're more concerned with our legacy, our reputation, and the trust that our readers have in Autoweek, Car and Driver, and Road & Track to deliver honest opinions and expert evaluations.

Visit our Tested & Trusted page to see the very best in automotive gear. Read more about our product testing and evaluation process here.

Katherine Keeler is an Assistant Testing Editor at Hearst Autos. By day she evaluates tools for your enjoyment; by night, she Frankenstein’s her ever changing fleet of rust-bucket-oddities back to repair. Her dream is to open a roadside attraction where the public can view, drive, and learn repairs at her emporium of curious cars.

Gannon Burgett loves cameras, cars, and coffee: a perfect combination for his Hearst Autos work. His byline has appeared in USA Today, Gizmodo, TechCrunch, Digital Trends, the Detroit Free Press, and more.

Collin Morgan is an Associate Commerce Editor at Hearst Autos, where the former Rust Belt mechanic and gadget enthusiast presents the best gear for your automotive endeavors.

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