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It can be frustrating to get your motorcycle out of winter storage and discover that the battery is dead. Or maybe you have a vehicle that’s been sitting for a long time that just doesn’t want to start. You can avoid costly battery replacements by properly maintaining the batteries in the first place. High-quality battery maintainers make life a lot easier. Once you hook one up to your vehicle, you can relax knowing it will start when you need it. Here are the best battery maintainers to choose from.
The Best Battery Maintainer
This 12-volt, 1.25-amp battery charger has two separate charging circuits. It’s ideal for both charging a battery and maintaining it at the proper voltage levels. It works on flooded, sealed, maintenance-free, AGM, and lead-acid batteries. It features Infinite Sequential Monitoring (ISM) to ensure your battery is safely charged at all times.
The maintainer complies with U.S. and international safety standards and features reverse polarity protection and spark-proof application, so you can “set it and forget it.” You connect this unit to the batteries and leave it without worrying that your batteries will become overcharged or damaged. The smart charger comes with a two-year warranty, two alligator clips, two sets of ring terminals, and a 72-hour safety timer.
12 volts and 1.25 amps
Features two independent charging channels
Has Infinite Sequential Monitoring
72-hour safety timer
- BrandBattery Tender
- Weight1.7 pounds
Complies with safety standards
Set it and forget it
One channel may burn out prematurely
Attached wires and connectors could be longer
Indicator lights are unreliable
This 12-volt maintainer is intended for motorcycles, ATVs, scooters, and automobiles. The device can be used on lead-acid, flooded, or sealed maintenance-free batteries, both AGM and gel cell. It features a 12-foot output cord, an 80-hour safety timer, and is reverse polarity protected.
The Battery Tender Junior is compact, lightweight, and completely automatic. It’s perfect for small spaces and features initialization, bulk charge, and float mode to maximize power without overcharging. The two-color LED indicators show the state of the charger, and when the voltage drops too low the device provides full output power. It comes with alligator clips and ring terminals for installation, as well as a five-year warranty.
Input voltage: 120VAC / 60Hz
Output voltage: 12 volts
80-hour safety timer
Reverse polarity protected
- BrandBattery Tender
- Weight1.8 pounds
Light and compact
Includes failsafe to prevent overcharging
May fail prematurely
May not connect well to an extension cord
Wiring is a little short
The Optima is both a maintainer and a charger that works with 12-volt AGM and flooded batteries. It features a USB charging port that works with smartphones, cameras, and tablets. The backlit LCD gauge features quick-set selections for ease of use. It’s designed to extend battery life and recovers batteries that have been deeply discharged.
This digital charger and maintainer charges faster than some of its rivals and produces up to two times the output. It will not overcharge a battery, it feels substantial, it’s well-made, and it’s easy to use. It allows you to choose auto/marine, motorcycle/powersport battery, or Optima batteries, and the LCD panel displays all the information you need.
Charges and maintains batteries
12 amp max
USB charging port for smartphones and other devices
Backlit LCD gauge
- Weight7.75 pounds
Has a large amount of output
Feels substantial and is easy to use
It’s a little expensive
Plastic case is not durable
Company may not stand behind its warranty
This maintainer can be used with eight batteries at a time and is compatible with cars, trucks, motorcycles, ATV, boats, and RVs. The device adjusts voltage based on temperature readings, so your battery is properly charged and maintained in all conditions. It also features reverse polarity and short-circuit protection.
The device uses high frequencies to reverse sulfation, which is the top cause of battery failure, and it also reconditions weak batteries. This extends the battery life up to four times versus batteries that are improperly maintained. It has 2-, 4-, and 8-amp settings, which are dependent on the shape of the battery. The maintainer also comes with a five-year warranty.
90-140 VAC 47-63 Hz input
Settings for 2, 4, or 8 amps
- Weight3.2 pounds
Reconditions weak batteries
Reverse polarity and short-circuit protection
Parts of the maintainer may get very hot
Y-connectors must be purchased separately
Customer service could be better
This device maintains up to four batteries at a time and works on automobiles, motorcycles, ATV, boats, and campers. It is a SmarTECHnology plug-‘n-run 1.5-amp battery charger and maintainer. It includes a high-frequency pulse desulfator to extend the battery’s life up to four times longer.
The device is compatible with 12-volt flooded, sealed, maintenance-free, starter, deep-cycle, Optima brand sealed AGM, and marine batteries. It includes reverse polarity, short-circuit, and over temperature protection. It includes a failsafe to ensure batteries are not overcharged or undercharged.
90-240V AC 47-63 Hz input
12-foot power cord
Insulated battery clips
Ambient temperature sensor
- Weight15.2 ounces
Reverse polarity protection
Won’t over or undercharge your battery
May stop working prematurely
Isn’t great at desulfation
Requires Y-connectors for parallel connection, which aren’t included
This 10-amp device charges and maintains one 12-volt battery. It is enclosed in a waterproof housing, which makes it particularly useful in marine environments, and can be submerged up to three meters. The charger is compact and lightweight and has the ability to detect, diagnose, recover, charge, and maintain lead-acid batteries. It’s compatible with flooded, gel cell, AGM, and deep-cycle batteries.
It offers protection against reverse polarity, sparks, and short circuits. It automatically and continuously monitors a battery and shuts off power when it detects a full charge. It comes with a five-year warranty, and the manufacturer calls it “one of the most advanced battery charges in its class.” In addition to boats, they’re great for golf carts, ATVs, and work trucks.
Reverse polarity protection
Shuts off power when it detects a full charge
- Weight1 pound
Compact and lightweight
Great for boats, ATVs, work trucks, and more
May fail after a short period of use
Indicator may be faulty
Sleep mode not ideal if there is a load connected
Best Battery Maintainer Buying Guide & FAQ
The best battery charger maintainers are built to completely charge and/or maintain your vehicle's battery. They send a small amount of electricity to the battery to keep it in operating condition when it's stored for an extended period of time. The best car battery maintainers are designed so they do not overcharge your battery.
They sense the amount of charge that is necessary to keep the battery functioning properly. The charge is transferred to the battery over a time period of several hours. Once the battery is completely charged, the maintainer will typically go into a float mode. When the device detects that the battery is losing power, it kicks on and resumes its job.
Benefits of a Battery Maintainer
There are several advantages to using the best battery maintainer for cars and motorcycles. It's a good investment because it will keep your automotive and bike batteries charged and ready to go. Vehicle batteries have a limited lifespan, and over time, the charge will drop to the point that it's nonexistent. If you use a battery maintainer, it will top off the charge, which extends the battery life.
Another benefit of using the best 12V battery charger maintainers is that you can store batteries when you're not using them. A battery will eventually lose its charge whether you're using it or not. A maintainer will ensure that it still functions optimally even when it's in storage. Plus, there's no risk that the battery will be overcharged or get damaged.
Finally, some of the best auto battery maintainers will actually restore an old battery. There are some brands that are a combination of a maintainer and charger. Depending on which model you choose, it can take an old lead-acid battery and bring it back to life.
- Extend battery life
- Keep stored batteries fully charged
- Restore old batteries
Types of Battery Maintainers
There are three types of battery maintainers: a single-bank maintainer, a multi-bank maintainer, and a hybrid maintainer. They each have their purpose, depending on what your needs are. You will need one type of maintainer if you're just charging one battery, while you'll need a different type if you're charging several at once.
Different Kinds of Battery Maintainers
A single-bank maintainer is the most common and basic type. It is designed to be used with a single battery and is usually less expensive than other kinds. Despite its simplicity, this type of battery maintainer can include some added features that make it perfect for use on a single car or motorcycle.
If you are storing just one bike, ATV, or classic car in the garage over the winter and want to keep it charged, a single-bank maintainer should do the trick. You don't need to spend the extra money on a device that has multiple banks if you're only going to use it on one vehicle.
This type of maintainer is useful if you want to maintain more than one battery at a time. The great thing is that you can choose the number of banks you require based on the number of vehicles you want to keep charged. You can get a device with two banks for two vehicles or as many as 10 banks for 10 vehicles.
These maintainers work on several batteries at once. The caveat is that you have to make sure that the cables are long enough to reach all the batteries. You may have to purchase additional hardware and cables to ensure that each battery is properly connected.
While you can just purchase a basic battery maintainer, you may want one with more bells and whistles. Some brands have a lot of features that make them more versatile. While certain types of battery maintainers only maintain the battery, others are able to charge it as well. If your battery is nearly dead, it has the ability to bring it up to a full charge.
Be sure to check that the device offers the features you require. For example, some even have the ability to recondition old batteries by reversing sulfation, which is the build up of sulfur crystals on the device.
What to Consider When Buying a Battery Maintainer
The batteries in your truck, motorcycle, ATV, and boat are all designed differently. While lead-acid batteries are the most common, there are other types as well. It's critical that the battery maintainer you select is compatible with the battery types it's expected to charge. There are also other factors you need to consider before making a purchase, such as amperage, charging modes, and safety features.
The Most Important Features with Battery Maintainers
The amperage is the amount of current that flows from the maintainer to the battery. Usually, a higher-amp device will charge faster. However, this isn't necessarily what you need or want. The best battery maintainer for motorcycles and cars are meant to be used long-term. That means that a low-amp device will use less energy in order to make sure that the battery is full.
If you're storing a vehicle for an extended period of time, you don't need a lot of amps. However, if you want to charge something quickly, you want a model that has higher amps.
- Charging Modes
If you purchase a high-amp battery maintainer, it will have several different charging modes for certain situations. For example, if the battery charger/maintainer has the ability to juice up a dead battery, in all likelihood it will have a fast charging mode. This enables the unit to deliver a lot of electrical charge in a relatively short period of time.
Another mode to look for is maintenance mode. This will keep your car, ATV, bike, boat, or camper battery charged over an extended amount of time. This is essential if you winterize your vehicles and want them to start right up at the beginning of the new season.
- Safety Features
Different battery maintainers have different safety features. They are important because charging a battery can potentially be hazardous. If you are unable to control the power, you can put yourself and/or the vehicle in danger.
The best 12V battery charger maintainers have spark-proof clamps as well as reverse polarity protection and short circuit protection. Smart battery chargers also feature voltage and amperage limits, so they don't overcharge the battery. These features will automatically kick in on smart maintainers, so you don't have to do anything manually to ensure that they are functioning properly and protecting your vehicle.
Tips for Buying and Using a Battery Maintainer
As we previously noted, charging a battery can be dangerous or ineffective if you do it incorrectly. Therefore, there are some things you should do to ensure that your battery is properly maintained. For example, there's a difference between maintaining a full charge and charging a battery that is low on juice. You need a higher-amp charger to revive a dead battery, but remember that this can be a slow process.
You can use a battery booster to inject life into a dead battery. It will provide just enough current for you to start a vehicle. However, the battery will need more amperage than one that simply has a low charge. Many people keep boosters in their vehicles for emergencies. Another advantage is they recharge low batteries quicker than standard chargers.
Battery maintainers can also provide you important diagnostic information. The best car battery maintainers will let you know when there is an issue with a battery that keeps it from properly functioning.
- Select a higher-amp charger if you need to revive a dead battery.
- Keep a battery booster in your vehicle for emergencies.
- Make sure your battery is functioning properly by paying attention to the diagnostics on the maintainer/charger.
Best Battery Maintainer FAQ:
By now, you know how important battery maintainers/chargers are for keeping your vehicle, motorcycle, boat, or RV up and running, especially if they've been sitting for a long period of time. But you may still have some questions about the devices, including how they differ from trickle chargers, how long they take to operate, and why overcharging a battery is not recommended.
Q: What's the difference between a battery maintainer and a trickle charger?
A: A trickle charger will transfer a constant charge to a battery, whether it's fully charged or not, while a battery maintainer will charge the battery until it's fully charged. It then changes to a float mode and will only charge it if the voltage drops.
Q: How long does it take to charge a battery?
A: The charging process depends on several factors, including the battery capacity and current. You can figure it out by dividing the capacity by the current.
Q: Why is overcharging a battery a problem?
A: Overcharging a battery can damage it, the charger/maintainer, as well as surrounding objects. The best automatic battery charger maintainers and those with float modes prevent this because they turn off after the battery is completely charged.
Our Top Pick
Our pick for the best battery maintainer is the Battery Tender 2-Bank 12V, 1.25A Battery Charger. It has two separate charging circuits, so you can use it on two vehicles, including a motorcycle battery. It both charges and maintains a battery, whether it's lead-acid, flooded, sealed, maintenance-free, or AGM. It provides some peace of mind because you can set it up and leave it without fear that it will overcharge or damage your battery.