Which battery tender to buy

There are several kinds of portable car battery chargers, including a solar battery charger. That said, if you're going to pick up a portable charger, you want to make sure it's the right one.

Here's a list of some of the best car battery chargers, depending on your specific car battery and charging mode needs, and based on user reviews and expert opinions. And make sure to keep reading for a deeper dive into the different car charger types. Read more: Best battery maintainers in When it comes to picking the right battery charger, the kind of vehicle you drive typically doesn't play a major role. After all, most cars, motorcycles, SUVs, trucks and other road vehicles use lead-acid batteries, which are relatively resilient and inexpensive to manufacture.

A charger that can power up a 12 V lead acid battery in an SUV can do the same for one in a motorcycle, for instance.

The best overall charger for your vehicle's lead-acid battery is the Battery Tender Plus it works with multiple types of lead-acid batteries, including absorbent glass mat and flooded. It's an automatic charger, with charge controller which means it will shut down on its own when your battery charge is full, preventing overcharging.

It even has a "float" battery maintainer mode that will keep it at full power during periods of inactivity, compensating for the self-discharge associated with lead-acid batteries. The 1. It's easy and safe to connect and disconnect, spark-proof, and checks to make sure a connection is established before transmitting power.

It's also cited as working well in extreme temperatures -- both hot and cold. The efficacy and user-friendliness of the Battery Tender Plus have earned it a good deal of popularity on Amazon: it's currently the site's fourth best-selling car battery charger, with a rating of 4.

What makes the Genius1 so popular besides its price is its versatility. It works with all sorts of batteries -- including lithium-ion, AGM and deep-cycle -- and both 6- and volt battery types. It charges and maintains batteries, with a trickle charge feature that keeps your battery charged over long periods of inactivity.

It also uses sensors to measure the temperature and adjust its 1-amp charge accordingly. Another feature that makes the Genius1 portable car battery charger useful is the fact that it can charge completely dead batteries.

Typically, this is a problem for automatic chargers, but the Genius1 has a "force mode" that allows it to function as a manual charger.

This means that it will deliver a continuous charge that proceeds unabated until you switch it off, and it can be used to resuscitate a battery with zero battery voltage. NOCO's Genius line also features models with higher amperage, providing more power and, if you desire, a faster charge. It's the Genius1, however, that delivers the best bang for your buck, making it an excellent introductory product when it comes to charging your own battery.

Battery chargers come in different sizes and power levels, with some of the larger ones possessing the juice required to charge a car battery as quickly as possible. However, some automotive battery chargers are so large that they're better used in auto garages than in consumers' homes. Finding a powerful automotive battery charger that also makes sense for home use is a delicate balance.

The Schumacher SC model offers the best of both worlds -- high power and handy maneuverability. The product can charge a car battery slowly with amps of power, but can also provide 30 amps for a quick boost -- or even to act like a jump starter.

The charging unit itself weighs about 12 pounds and has a handle to make carrying it easier. Despite the power that it delivers, the Schumacher SC charges with finesse: it's an automatic smart battery charger so you don't need to worry about overcharging your battery, and the trickle charge feature lets you easily keep an unused battery juiced up. The charger's reverse polarity protection ensures that it can't be used if the clamps are attached to the wrong car battery terminal, helping it function more safely.

Deltran's Battery Tender Plus ranks as our top overall car battery charger, but the company's Battery Tender Junior is the perfect choice if you're simply concerned about long-term battery storage. There are definitely some things to consider that may limit this type of usage. Think about how consumer electronic products are used and consequently, how they are designed. To keep the price low and competitive, it is important to limit the battery charger applications to a realistic, manageable portion from the vast number of ways in which a battery charger may be used.

The simplest applications involve charging and maintaining vehicle engine start batteries. The advantage in this application is that there is almost always another, larger source of electric power to charge the battery while the vehicle is running.

So the off-line engine start battery charger need not normally supply the full amount of charge stored by the battery. One common exception would be when the vehicle battery is drained because lights were left on. The point is that the engine start battery charger is not normally expected to deliver its maximum charge current for extremely long, extended periods of time.

As long as the automotive electronics system is functioning properly, there should be no problem. Typical automotive electronic systems run on the alternator output of approximately 14 to 15 volts. Typically, power sports engine start batteries are in the 12 Ah to 20 Ah capacity ranges.

Both chargers are constant voltage type with precisely regulated output current limits. Both chargers have a regulated, nearly constant 1. Physically, there is virtually no difference between these 2 chargers.

Both the Battery Tender and the Battery Tender Plus operate in 3 charge modes, bulk charge, absorption charge, and float charge. These specific changes were made to accommodate the charging requirements of Absorbed Glass Mat AGM style lead acid batteries. Background: The motorcycle dealers receive batteries from the manufacturer in a dry state.

The plates are dried out, and there is no acid in the cell compartments. Do not confuse this with a dry-cell battery.

The dealer must fill the individual battery cells with acid and then put them on a shop charger to pre-charge prior to selling them to a customer. The initial pre-charge, post-formation charge, or more correctly, formation-finishing charge, must be conducted at a specific power level and for a specific time period.

For example, a 16 Ah battery will take about 13 hours to get to the absorption voltage constant It may take another 6 to 8 hours to reach the float voltage constant This may sound awkward; because what happens is that the battery charge current drops while the absorption voltage is held constant. When the battery current drops to 0. So it may take the better part of 20 hours to reach the float stage. Add another 24 hours to that and you are at 44 hours.

Throw in another 4 hours for good measure and you get a nice round, even 48 hours, or 2 days. Qualification B Although there are probably several charging methods that will be equally effective, regardless of who manufactures the battery, in the interests of technical consistency, they will not officially sanction any initial charging method other than those published in their technical applications literature.

You would think that a 3 amp charger would recharge a battery roughly 3 times faster actually only 2. There are 2 main reasons why this is not true. First, the way a battery reacts to charge current is complex. Second, and just as important, is the way that battery charger manufacturers rate the output current of their charger products. The dimensions or units describing electrical charge are the Coulomb or, more conveniently in the context of battery charging, the Amp-Hour. The abbreviation for amp hour is Ah.

A battery charger delivers charge amp-hours to the battery by using an electrical current Amps at its output over a period of time Hours.

The numerical product of the electrical current and time period is the amount of charge delivered. This is true in a general sense for any charger. Marketing and sales people like big performance numbers because they believe that those numbers enhance the perception of value. The truth is that the best value for a battery charger should be based on the total cost of ownership for both the charger and the batteries that it is charging and maintaining.

Once the AC power is removed from the Battery Tender Plus battery charger, the green light will go out and the charger not have any effect on the battery. The Battery Tender Plus battery charger is protected from reverse current, so it will not discharge the battery. Of course, like we said earlier when discussing nominal voltage mismatches between a battery and a charger, the battery will not be recharged either. When AC power is restored to the Battery Tender Plus battery charger, it will restart its charge cycle.

The sequence of events should go something like this. The red light will come on for a few minutes. Then the green light will start flashing while the red light stays on. The next thing that happens is what may confuse some people who use the Battery Tender Plus battery charger.

The charger immediately tries to bring the battery voltage up to about This takes a finite amount of time, although it should only be a few minutes if the battery is fully charged. Then, when the battery reaches Either the battery charge current will drop to less than 0. There are a couple of reasons why the battery current may not drop below 0. First, on a larger battery, like an automotive SLI battery, the internal losses of the battery may consume more than 0.

Second, if the vehicle or the system that the battery is connected to has appliances that consume electricity, then that consumption of electricity, coupled with the battery internal losses may very likely exceed the 0. So it will take 6 to 8 hours for the green light to come on.

Fortunately, the Battery Tender Plus has the ability to continue to supply its full current even after it has switched over to the lower, float, maintenance charge voltage of When the charger turns the green light back on, it also drops its output voltage to this float, maintenance charge level of The actual maximum and minimum battery sizes these products can charge and comply with energy efficiency requirements are as follows:.

If you have any questions, please contact DBT customer service at: , or email service batterytender. Visit Product Page. As long as the Wireless Battery Monitor is connected to a Wi-Fi network, you will be able to access the Wireless Battery Monitor no matter the network you are connected to.

Once you have added a Wireless Battery Monitor to your account, you can login to the Deltran Connect app one or more mobile devices and read the status of the Wireless Battery Monitor. It needs a period of time to learn the vehicles battery. As long as your router sends an To view information of each individual battery, there needs to be Wireless Battery Monitor installed to each battery.

The Wireless Battery Monitor requires little power to operate. The amount of time it can be installed without the vehicle in use will vary due to different battery sizes, age of the battery, condition, etc. If there is no red triangle it is already connected a Wi-Fi network.

The Wireless Battery Monitor will only work with a 12v system. Anything above 15V will damage the Monitor. If possible, have a dedicated SSID for the 2.

The Wireless Battery Monitor tracks the state of charge of your battery. If the battery appears to be discharging, an alert is pushed to your mobile device. On certain Android smart phones, the phone will drop the connection to the Wireless Monitor and re-connect to your WiFi router or to your mobile data network. This is caused by a setting on some phones that is called "Smart network switch". If the phone determines it has not data connection, it will revert to the most recently used data connection.

If this happens while setting up a Wireless Monitor, the setup will fail. To work around this, temporarily disable the "Smart network switch" or do not allow it to switch network connections if prompted. The IP address can be changed if you want. Check Price. Battery Tender Plus 1. It works as advertised!

Keep putting it on the charger after every ride, and there will be no more jumper cables each morning. Check Price at Amazon. Pros Can charge power sport vehicles boats, etc. Cons Not powerful enough to charge a car battery. Battery Tender 4A is a versatile device that can charge both 6V and 12V battery systems regardless of lead-acid or lithium ones.

Pros Can charge both 6 and volt battery systems Powerful enough to charge and maintain car batteries Charge 12V Lithium batteries Small overall size. Cons No temperature sensitive charging control. Highly recommend it for cars that are heavy in electronics or if you need a versatile charger for all jobs in your garage. Cons Cannot charge 6 volt systems No temperature sensor. Bonus: Ctek 4. Related Posts. About The Author. Tim Miller Tim has over 8 years of experience in car charging system repair.

It's also a highly regarded motorcycle battery charger, with 4. Using a solar charger or maintainer isn't just good for the environment, it's also convenient. You still have to hook it up to your car's battery, but you don't need to hook the other end up to an electrical source. That means you can maintain your battery wherever you are, so long as there's some sunlight for a solar panel to collect. It's available in a variety of wattage levels, but for the purposes of this piece we're focusing on the BC-6W model, which delivers 6 watts of power.

It offers a continuous charging process, but also has a protection against overcharging, meaning you can leave it plugged in as long as you need to without worrying about damaging the battery. Another great feature of the Suner Power 12V battery charger and maintainer is how easy it is to use. You can hook it up to the battery by plugging it into your car's lighter dock, if it has one. If it doesn't -- or if your car's lighter won't operate when it's off -- it comes with alligator cables, as well.

When considering purchasing a battery maintainer, it's important to remember that it's not the same thing as a battery charger -- although there are many models that do both. A charger is designed to give a charge to a battery, filling it up from a depleted state and, depending on the charger, maybe even bringing it back from the dead. A "smart" charger automatically shuts off when the battery is full, while a manual charger continues to deliver the same charge as long as it's plugged in.

The latter poses the risk of overcharging. Melanie creates written and video content on the topics of automation technology, vehicle safety and insurance. Thankfully, car batteries are designed with safety features to prevent explosions, so the overcharged exploding battery is essentially an urban legend. Undercharging a battery leads to sulfation. When you try to recharge the battery, the sulfation blocks the charge from doing its job of recharging.

By contrast, car battery maintainers are all "smart" -- they have sensors that allow them to "know" when they're connected to the battery terminal of low batteries and full ones. Once a battery is completely charged they stop delivering a charge. Also, the charges that they deliver are typically of lower amperages than those of battery chargers. Since maintainers are used for maintenance during periods when cars aren't going to be used, time isn't of the essence when charging.

This means that a maintainer can give a battery a "low and slow" charge, which is better for its health than a faster charge or a jump. Williams has over 15 years of automotive and DIY experience across a variety of industries.

Fast charging will cause issues and reduce battery lifespan over time. So always trickle charge when you have the time to do so. Though battery maintainers work similarly to trickle chargers chargers that come in smart or manual varieties and deliver consistent low-level charges to batteries -- and sometimes the terms are even used interchangeably -- they are not the same thing and should not be used in place of one another.

Trickle chargers are meant to be disconnected when they're done charging, while battery maintainers can be left plugged in. Remember, since all battery maintainers are "smart," they won't deliver any charge to a battery that's already full. Sometimes maintainers are called "float chargers," after the "float" mode in which they remain.

In this mode, they activate to refill standard discharge and then turn off again. This may cause some confusion, but they're distinct from trickle chargers. So, as the battery reaches full charge, the maintainer stops charging the battery.