The Best Battery Maintainers

Deltran has a wide range of offerings, and the Battery Tender Plus is our best overall pick. This is a 1.25A battery charger that is designed to fully charge a battery and maintain it at proper storage voltage without the damaging effects often found with trickle chargers.

Included with the Battery Tender Plus is a quick-connect harness, along with ring terminals and alligator clips. The power cord is 6.0 feet (18AWG), while the DC output cord is 4.5 feet long (18AWG). Safety features include reverse polarity protection.

What makes this product the ideal battery maintainer is that it automatically switches from full charge to float charging mode to maintain your battery. The company also includes an impressive 10-year warranty.

NOCO is perhaps the industry’s biggest name in battery maintenance. One look at the NOCO GENIUS1 and it is easy to see why.

Ultra compact and smartly designed, the GENIUS1 is a 1-amp (15-watt) device that is designed to keep 6-volt and 12-volt batteries going strong. The GENIUS 1 can charge all types of lead-acid and lithium-ion batteries while also repairing battery damage. Thanks to an integrated thermal sensor that recognizes ambient temperature, the GENIUS1 ensures it will not accidentally overcharge when it’s hot or undercharge when it’s cold.

NOCO outfitted the GENIUS1 with slow-pulse reconditioner technology, which can detect both battery sulfation and acid stratification. Once it recognizes the issues, it can repair them and restore your battery’s performance.

The package, which is small enough to fit in your glove box, comes with everything you need to keep your batteries topped up and performing their absolute best. It is fully compatible with your car, truck, ATV, motorcycle, RV, or boat.

If you're using a battery maintainer, there's a good chance you will be using it often. That means you might not want to have to remove and re-install the charger every time, connecting and disconnecting to the battery over and over.

The Schumacher SC1300 is designed to be installed semi-permanently in your vehicle. It has mounting holes to attatch it to a fender liner, firewall, or other surface. Plus ring terminals to secure it to your battery even if you're driving. Then you just plug it in using the attached cord and unplug when you're ready to leave. Like a block heater, but for your sports car.

The SC1300 delivers 1.5 amps, plenty to keep even the biggest vehicle batteries topped-up. It will automatically detect 6 and 12-volt batteries, and it has reverse polarity detection for safety.

BLACK+DECKER is likely a brand you are familiar with, and the company offers a fully automatic battery charger/maintainer that can charge 6- and 12-volt AGM, GEL, and WET batteries. It's a fairly basic battery maintainer that is affordable and easy to use, simply connecting to your battery with battery clips or O-ring terminals. As a maintainer, it'll automatically stop charging once the battery is fully charged or topped off, switching to float mode monitoring to maintain the battery.

Built-in circuit protection prevents overcharging, reversing polarity, or short circuits. This battery maintainer is ETL certified for performance and safety. As a small plus, a built-in mounting bracket makes it easy to place the maintainer somewhere convenient.

BLACK+DECKER includes a limited 1-year manufacturer warranty with this product.

Cleveland-based NOCO* has come to dominate the jump starter market, even being sold as a factory option in some new cars, and is known as an industry leader. The genius5 is no exception, combining battery charger, maintainer, trickle charger, and desulfator functions in one very small unit.

Replacing the G3500, the Genius5 is 35% smaller than the old model while providing 60% more charging power. It operates at 6 and 12 volts, with 5-amp, 75-watt charging for lead-acid automotive, marine, and deep-cycle batteries, including flooded, gel, AGM, and maintenance-free, plus lithium-ion batteries. Unlike many car chargers, it automatically works with as little as 1 volt remaining, or you can manually override and attempt to charge a fully dead battery. NOCO also claims it will detect the performance loss from a damaged battery and enter a repair cycle. It also has a thermal sensor to account for external temperatures so that you can use it from -4°F/-20°C to 104°F/40°C. Once a battery is fully charged, the genius5 automatically switches into maintenance mode for as long as you leave it connected.

The trickle charger itself is 4.61 x 3.43 x 7.95 inches, and it weighs 1.59 pounds. A mounting strap and screws are included if you want to tuck it away permanently under a hood, or strap it to a battery on a shelf. Voltage, damaged battery, reverse polarity, and temperature warnings and safeguards are built in. NOCO’s fix-or-replace warranty is five years.

*NOCO means “No Corrosion,” for a product the company founder Joseph Henry Nook developed in 1914 ( and which they still sell). The Nook family still runs NOCO.

One of the most affordable options on our list comes from MOTOPOWER with its fully automatic battery charger/maintainer. Designed to charge all types of 12-volt lead-acid batteries, this maintainer features a microprocessor-controlled program that will monitor the entire charging progress and automatically stop once the battery is fully charged. This is when it will start monitoring the battery's voltage and maintain the battery with a float charging current. Constant Pulse Current Maintenance also aids in making sure the battery doesn't excessively charge or discharge.

Safety features on this device include overcharge, short circuit, and reverse polarity protections, along with being sparkproof. You can use ring terminals or alligator clips to attach this battery maintainer to your car's battery. You can also quickly connect and disconnect the maintainer from your car's battery using the included harness. The device is certified by CE, RoHS, UL, and CEC and comes with a 2-year warranty.

Another option that works with both 6.0- and 12-volt batteries comes from LeicesterCN. This battery maintainer can be used as an automatic trickle charger, and after it's done monitoring the whole charging progress, it will automatically switch to float mode. This maintainer also provides visual feedback and diagnostic information, even in maintenance mode, so you can keep an eye on how your battery is doing.

This is an ultra-compact and lightweight battery maintainer, which also makes it great for motorcycle owners. This spark-proof device has reverse polarity protection as a safety feature.

LeicesterCN offers a lifetime quality warranty for its battery maintainer and a 12-month refund policy.

You may not know the TecMate name, but the Belgian company manufactures battery products for companies including Honda, Triumph, Ducati, and Aston Martin. Tecmate also makes its own line under the Optimate name, often identical to factory accessories but without the brand name. That includes the Optimate 1 Duo, a simple and effective 0.8A, 12V/12.8V battery charger/maintainer.

This little 1.2-pound, 7.0 x 6.0 x 3.0-inch unit is designed to work with not just AGM, GEL, STD, starter, and deep cycle batteries but lightweight lithium batteries as well. It automatically detects the battery type, taking the worry out of maintaining and charging batteries in motorcycles, ATVs and UTVs, lawn and garden equipment, jet skis, and more. There's literally nothing to do—you attach it to the battery, and it does everything. It's intended both for charging and 24/7 automatic maintenance use—perfect for seasonal vehicles.

Tecmate Warranty and Customer Service

All of TecMate's battery products have excellent ratings, and the Optimate 1 Duo is one of the best, with an outstanding 98% positive rating and over 200 reviews. The Optimate line has a three-year warranty. The only thing keeping TecMate out of the top spot on our list is the lack of customer service. There's only a web form on the Optimate1.com site; you must find your way to the TecMate.com site to get a local California number. The Optimate1 site does have extensive documentation, FAQs, and even videos for most products, including the Optimate 1 Duo.

Schumacher offers various battery maintainers, depending on the amperage and charge rate you require. Options include 0.75A, 0.8A, 1.5A, 2A, and 3A. These options are powered by a microprocessor that automatically adjusts the amperage rate to charge and maintain the battery. Multi-stage charging contributes to precision, safety, and battery life, while reverse hookup protection ensures the charger won't function if the clamps are reversed.

The more affordable battery maintainers from Schumacher are more basic, with just a charging status LED indicator. Other units have a display with a start/stop interface that is easy to use. Most do have float mode monitoring to ensure an optimum battery charge for maintenance.

This 5A smart battery charger/maintainer is designed to work with 12-volt batteries and comes from BMK. If you're using this as a battery maintainer, it's best to make sure the battery capacity is higher than 15Ah. Constructed from high-quality ABS, this battery charger/maintainer is IP65 waterproof, and safety features include protection against short circuit, over-voltage, overcharging, overload, and reverse polarity protection. This device also uses Constant Pulse Current Maintenance to avoid overcharge and discharge.

Along with a spark-proof design, using this device is easy thanks to a quick disconnect harness. There is also a built-in 72-hour safety timer, which protects marginal batteries from overcharging.

BMK includes a lifetime quality warranty with its battery charger/maintainer.

Another reputable brand on our list is DieHard's smart battery charger/maintainer. Designed for both 6- and 12-volt batteries, this is a fully automatic, microprocessor-controlled 5-stage charging system with LED indicator lights to show progress. Safety features prevent overcharging and will shut off the device if your clamps are reversed. As a battery maintainer, Float Mode Monitoring will keep your car's battery at a normal voltage to maintain the battery's charge.

DieHard includes a 3-year warranty with this specific product, along with a handy quick-connect harness. Connection options include 50-amp clamps, a 12-volt accessory plug, or permanently attachable ring connectors.

DieHard also offers more expensive options in the form of a Gold Shelf Charger and a Platinum Shelf Charger if you need something more heavy-duty.

What's the Difference Between a Trickle Charger and a Battery Maintainer?

How do I Choose the Right Battery Maintainer?

How Does a Battery Maintainer Work?

Battery maintainers work by delivering a steady electrical current to maintain a car battery's charge over long periods of time.

Can you leave battery maintainers on all the time?

In theory, this is the idea behind a battery maintainer, and most operate constantly without you having to maintain them. Please check your specific product for guidelines on use.

Can a battery maintainer charge a dead battery?

While there are certainly better methods of doing this (battery jump packs, for example) a maintainer will hypothetically charge a battery, though we’d recommend using other methods.

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