One of the most common symptoms of a car battery that has run its course is that it depletes really fast when not used daily. Even newer batteries often go flat when left sitting for a few weeks. That has the potential to leave you parked somewhere with a dead battery which will require a jump start and a full charge after that. Luckily, most of the best car battery chargers today come with a built-in jump starter mode, as well as a battery maintainer mode. In other words, look for the all-in-one models that will make sure your battery stays healthy throughout its life cycle.
In this buyer’s guide, I will show you the top models for this year and then we will go through the features that define a good car battery charger. Later on, we will also dedicate a whole section to properly charging your car’s battery and the steps you need to take during the process. now, without further ado, let’s jump straight into it!
Car Battery Chargers Comparison Chart
Schumacher SC1308 6/12V Fully Automatic Battery Charger
The Schumacher brand has been dominating the battery chargers and maintainers market for quite some time now. Their SC1308 Fully-automatic battery charger is one of the current best models due to its wide range of functions and compatibility.
The charger works at both 6 and 12 Volts, allowing it to widen its battery range. The voltage is automatically detected making it easier for your to work with multiple batteries without worrying that you will damage them. In terms of safety, it also has a reverse hook-up protection that keeps both the battery and the charger safe. The charger can also double (or triple) as a battery maintainer and a jump starter. For its battery maintainer mode, it works between 2 and 6 amps depending on your battery’s needs. Regarding maintaining your battery’s health, it also has a microprocessor that takes care of the charger’s “Float mode” which allows the battery to safely stay at 100% without deteriorating its long-term life and quality. The SC1308 also has a 30-Amp mode that is used to quick-charge Standard and AGM batteries. Lastly, the crank mode uses a 100 Amp current. While this is enough for most smaller engines, bigger diesel and petrol engines won’t crank up with that low Amperage.
There are some small additional features that fill up the image of practicality. For instance, the built-in cord storage isn’t something you necessarily need but is really convenient to have, especially if you move the charger from place to place a lot. There is also an advanced diagnostics test for your battery and an easy to read user interface with a large display and equally big buttons. One notable downside of this, or any other Schumacher product for that matter, is that it is quite expensive compared to other chargers with similar metrics.
- Automatic Voltage detection
- Works at 6 and 12 Volts
- Has a battery maintainer and jump starter modes
- Chargers fast at 30 Amps
- Material quality is market-leading
- Easy to read display and interface
- Weak jump starter mode
Clore Automotive PL2320 6/12V Battery Charger
The Clore Automotive PL2320 battery charger is a compact model that is quite diverse in its features and presents a good value for the money deal if you’re looking for solid charger/maintainer combo. It works with 6 and 12 Volt AGM, Gel, and STD batteries and can charge them at either 2, 10, or 20 Amps. The 10 and 20 Amp modes are primarily used for quickly topping up your battery, while the 2-Amp mode is geared towards maintaining bigger batteries or slow-charging a smaller battery. All the charging and maintaining here is fully-automatic, meaning it has an integrated “Float mode” and a multi-phase charging process.
The interface at the front of the charger is very user-friendly. On the left, you have your battery-types and Amperage options. There, you can toggle between 6 and 12 Volts, the type of battery you’re charging, and the Amperage you want to select for the process. In the middle, there is a big easy-to-read display that shows you either the percentage of charging or the current Voltage. Below that is the start/stop button. On the right, you have your “Status center” which has 2 big lights for the charging progress and two smaller ones for the reverse-polarity protection and potential safety issues or errors.
A little pet peeve of mine with this charger is that it isn’t officially compatible with some sealed lead-acid batteries. It also isn’t very easy to hold and carry around if you’re moving it constantly. Also, at that price range, some chargers have jump-starting features, while the PL2320 doesn’t.
- Decently priced
- Quality cables and clamps
- Solid construction
- Detailed control panel
- Works as a maintainer and charger
- Fully-automated charging process
- Not very compatible
- Hard to carry around
Schumacher SC1309 Wheeled Battery Charger
Having another Schumacher entry in this top-6 list is a statement of their brand quality and diversity. While the brand’s flagship SC1308 is potent and highly portable, there is an even bigger and more widely compatible version. That is the Schumacher SC1309 Wheeled battery charger. As the name suggests, the standout difference is that this charger is bigger and therefore in a different form-factor. It is also much more powerful with a 200-Amp jump-starter boost and a 40-Amp charging. There is also a 2-6 Amp maintaining mode that helps to keep your batteries topped up during their off-season.
As with every Schumacher battery charger, there is a microprocessor on the inside which controls the multiple-phase charging as well as the Float mode for battery maintaining. Unlike other products of the company’s line up, however, the SC1309 has a more sophisticated control panel that has buttons and indicators for every single function of the model. While that might complicate its user-experience a bit, it makes it a wonderful widely-compatible tool for larger garages. The clamps with which it comes are also bigger mainly having trucks and SUVs in mind.
In terms of safety features, there is reverse-polarity protection which is standard to the company’s chargers. There are also battery and alternator test options which can tell you their health status and battery levels. These modes also help you diagnose potential issues along the electrical system of the vehicle. As potential downsides, I can only point out that the price isn’t ideal for people with smaller vehicles and/or small garages. While this is a highly capable charger/maintainer, there are cheaper models that can do just fine with your car’s battery if you aren’t driving a large truck or SUV.
- Wheeled design helps with moving around
- High-quality large clamps
- Has charger, maintainer, and jump starter modes
- Works with 6 and 12 Volt batteries
- Perfect for large trucks and SUVs
- Reverse-polarity protection
- Battery and alternator test modes
- Not ideal for small garages
NOCO GENIUS5 Fully-Automatic Smart Charger
Ever since NOCO products appeared on the market, they’ve quickly covered the top spots in any list regarding portable battery chargers and jump starters. The NOCO Genius5 is one of their bigger most potent products that is capable of charging a wide variety of batteries.
One of the standout Genius5’s features is its form-factor. This is by far the smaller and most powerful battery charger that you can find out there. While it is a little expensive compared to other similarly sized chargers and maintainers, it is worth the investment. It works with both 6 and 12-Volt batteries and it can detect the battery’s voltage even if it is as low as 1 Volt. If the battery is or drops below 1 Volt, the Genius5 will automatically begin charging them. Its wide range of batteries it works with consists of Flooded, AGM, Gel, Marine, and Deep-cycle batteries. In terms of its Amperage, it charges at a fixed rate of 5-Amps. While there is a Float mode to keep your battery topped up, it will struggle with fully charging a dead battery from 0 to 100% if it is a large SUV/truck type battery and will take more time on average than other chargers that operate at 20-30 Amps.
One other unique feature of the Genius5 is that it has a Thermal Compensation mode which works according to the ambient temperature of your garage. If it gets above 104 degrees Fahrenheit, it will prevent over-charging your battery, while if the temperatures drop below -4 degrees, it will avoid under-charging it. That is great for the long-term health and performance of any vehicle battery. It also comes with a battery desulfator, acid stratification detection, and auto-repair modes that add more on top of its list of unique traits.
As I previously pointed out, while the Genius5 is quite powerful for such a small device, it is also quite expensive when compared directly to other small chargers. It also is relatively week (5-Amps) when it comes to charging bigger SUV and truck batteries fast. It will charge them alright but at a slower pace than a 30-Amp charger, for example.
- Widely compatible
- Automatic voltage detection
- Auto-repair mode
- Acid stratification detection
- Reverse polarity-protection
- Thermal compensation function
- Super small and durable
- Won’t charge large batteries fast
- Relatively expensive
Jethax 12V 4A Smart Car Battery Charger
The Jethax Smart Car Battery Charger is one of my favorite budget products right now. It is versatile, and most importantly – it can charge, repair, and maintain a wide variety of batteries.
The charger works at 4 Amps and 12 Volts and is compatible with all sorts of batteries such as AGM, Gel, VRLA, Deep-cycle, Marine, and SLA. One of its limitations, however, is that it can handle lead-acid batteries only in the 4-100 Ah range. If you have a truck or an SUV, chances are that your battery will be bigger and therefore this charger will only be able to maintain it at a certain spot or charge it at a very slow pace over the course of a few days. When charging, the Jethax utilizes 4 different modes – initialization mode, bulk charge, absorption mode, and a Float mode to keep things steady at the end of the charging cycle and maintain the battery’s longevity.
While it isn’t typically expected at that price point, the alligator clips and ring terminals are of decent quality, and so is the body of the charger. It also has reverse-polarity protection, as well as protection against overcharging, discharging, over-current, sparks, short-circuiting, and even overheating. As one of its biggest disadvantages, I should point out that it only works with 12 Volt batteries but that is also fairly typical for this budget class chargers.
- Very cheap
- Uses 4 different charging modes
- Works with a wide range of batteries
- Has a ton of safety features
- Doubles as a charger and maintainer
- Doesn’t work with 6 Volt batteries
- Not strong enough for some bigger SUV/truck batteries
Battery Tender Plus Battery Charger
Last on this list is the Battery Tender Plus Battery Charger. It is one of the most commonly used chargers out there due to its affordability, good quality, compatibility, and ease of use. it is by no means a potent charger and it will definitely not charge your battery as fast as you’d want to so treat it more like a battery maintainer or trickle charger at best. Still, people with smaller vehicles and batteries tend to love the consistent and low current this charger provides.
There is an ongoing debate on whether slow-charging is better than fast-charging, especially when it comes to car batteries. While I won’t take sides, I would just say that if you have the time to spare, slow-charging seems more logical, as it will gradually turn into maintaining and float-charging the battery, ultimately increasing its performance once you start using it in your vehicle. The 1.25-Amp, 12-Volt charging works with Standard SLA batteries as well as AGM and Gel types.
As with most other chargers, you get reverse-polarity protection here. When the charger detects a faulty connection, its red and green lights will flash alternately to let you know about the issue. As I previously mentioned, my main problem with this charger is that is simply doesn’t cut it when it comes to fully charging batteries. Also, there isn’t a 6 Volt mode for 6V batteries. Which narrows its range a bit.
- Excellent slow-charging properties
- Compatible with a lot of battery types
- Good material quality
- Comes with all needed cables and extensions
- Good for small vehicles
- Doesn’t work with 6-Volt batteries
- Tends to run how when charging for a long time
Car Battery Chargers Buyer’s Guide
Batteries are an essential component of your vehicle. However, people often disregard them and rarely think about their health and long-term performance. That is one of the main reasons most people have batteries that deteriorate faster than normal and can often leave them stranded on the road or in the best-case scenario, put an unnecessary amount of strain on their vehicle’s alternator.
Before we get into the do’s and don’ts of charging your car’s battery, let’s discuss some of the most important features that you should consider when cross-shopping different car battery chargers…
Car Battery Charger Features
A good battery charger should be widely compatible and also potent enough to cover your battery’s energy needs. Good all-rounder models perform well in all of those categories:
- Charging Capacity & Compatibility
- Design & Build quality
- Safety features
- Extra features & accessories
Charging Capacity & Compatibility
The capacity of a battery is mainly determined by its Amperage. The amps at which it works also determine, to an extent, how compatible is going to be. Low-amperage chargers aren’t strong enough to charge up big SUV and truck batteries, while higher Amp models can charge both big and small ones. The voltage also determines a battery’s compatibility. While most chargers work at both 6 and 12 Volts, others only work at 12, making them less desirable by people that have both types of batteries. Some models like the NOCO Genius5 can detect voltage drops and even charge up batteries from 0 Volts.
The charging capacity can be also supplemented by various charging modes that perfect the process by implementing precise calculations. The most common mode used by almost all chargers and battery maintainers is the Float mode which keeps your battery at 100% by charging it up every time it dips under a certain threshold.
The practicality of a battery is determined by its design, accessories, and how easy it is to move around. Things like indicators and a detailed control panel also help with the ease of use.
While control panels are often overlooked by people thinking they only need a button or two, they are essential to the functionality of the device. A detailed control panel can give you various types of information such as the detected voltage, the amperage used for charging, the charging level, the typ eof battery the charger detected, and the stage of charging. It can also give you control on whether you want to quickly charge up the battery or jsut trickle charge it and keep it at 100% for the winter, depending on the charger type.
Design & Build quality
The design of the battery charger shouldn’t be your first consideration but it definetely is important if you move around a lot and you need the charger by your side. A solid build quality paired with a top handle or a design that is portable is a must-have combination for any technician that needs the charger by his side when he’s on the road fixing dead batteries or faulty alternators. A good feature to have in that situation would be a jump starter with high cranking Amps.
The build quality of the charger also translates to its accessories with the clips being the prime example of that. Well-build charger with poorly build clips is a bad combination. If that is your case, I suggest investing a little more in a solid pair of alligator clips that will ensure proper flow of the electrical current without disruptions or sparks.
Speaking of sparks…
There are numerous safety features that a car battery charger should have. Some of the most important ones are:
- Reverse-polarity detection
- Protection against overcharging and overheating
- Protection against discharging
- Over-current protection
- Sparks and short-circuiting protection
Along with those safety features, there can be a thermal compensation mode which will work in according to the ambient temperature by controlling the electricity flow towards and from the battery.
I touched on that briefly a few moments ago but it is important to mention it again. While most trickle chargers are made for garage use, real battery chargers are often bigger and require a bit more practical approach to their design. A top handle is often the best way for manufacturers to tackle the bulky size of their chargers. Wheeled models aren’t rare either. Wall-mounting your charger is a good idea but if you want to bring your charger in case your battery or alternator die on the road, then you need it to be portable and in a practical form-factor.
Extra features & accessories
There are a lot of additional features that you might want to get on your car battery charger. But are they all worth it? Well, depending on your budget it might not always be the best idea to get all the bells and whistles and the highest-end models since they are oftentimes uselessly packed with otherwise unnecessary features. That is especially true if garage use is the only thing you will expect from your charger. Nevertheless, one of the most desirable features of a charger is its jump-starting capability. While some models have 1000 cranking amps, typically anything more than 200 is good enough to start most bigger diesel and petrol engines. Models with less than that will struggle with the big engines but will successfully manage to start a smaller boat or motorcycle engine.
Other extra features include various internal components such as a charging microprocessor that handles complex tasks such as coordinating float mode or other types of charging phases. Handles, wheels, extra cables, and other accessories are also a plus unless they bulk up the price out of proportion.
Benefits Of Using Car Battery Chargers
There is a common belief that car batteries should only charge on their on from the car’s alternator when you’re driving the car. That, despite being partially true, isn’t ideal for your battery’s life and long-term performance. Fully charging and then trickle charging your battery a few times per year is one of the best things you can do for it. Not only will that increase its performance but it will prolong its service life greatly. Typically, a modern car battery starts fading around its 5th year if treated poorly. If you treat your battery well and charge it up nicely it can last up to 10 years or even longer. This is especially true if you’re using it for short-distance runs most of the time.
If you don’t have a charger, the best way to keep your battery in a good shape is to do a longer run at least once per week.
How To Charge A Car Battery
Before I give you the steps on how to charge your car’s battery, you must make sure that you read the user manual of the charger carefully. Typically, all the necessary instructions will be laid out there but I will be giving you the universal steps which are more or less identical across all models:
- First and foremost you must make sure that your car battery charger supports the type of battery your vehicle has. There are many types of batteries like AGM, Flooded, Gel, Marine, Deep-cycle, Lithium-ion, and others. Not all chargers are compatible with all of those and compatibility is a major point here. Secondly, make sure that the voltages are compatible. Some chargers only with 12-volt batteries and aren’t compatible with 6-Volt ones.
- Your second step would be to disconnect the battery from the car’s cables. First, remove the negative cable (black) and then the positive one (red).
- Make sure that your car is turned off and that your charger isn’t yet plugged into an outlet.
- Connect the positive (red) cable of your charger for the positive terminal and the negative cable (black) to the negative terminal.
- Once that is done, adjust your charger’s amperage if it has that option (trickle charging or fast charging). Most modern chargers are automatic so you don’t have to worry about the correct setting.
- Turn the charger on
- When you finish charging the battery, turn off the charger first then remove the negative cable (black) and then remove the positive one (red)
Choosing The Right Car Battery Charger Size
When thinking about charge times the primary two attributes to take into account are engine size and amperage. Engine size directly correlates to the battery size needed to power it so it is more or less the same thing. The Amps are related to the speed with which the charger will charge a specific battery. The more Amps the charger has, the faster it will charge. We can divide vehicles and their batteries into the following groups:
- Small motors, boat motors, motorcycles – To charge a battery for these types of motors fast, you typically need a 5-10 Amp battery charger. Anything more than that would be an overkill and will disproportionately increase the price-to-value ratio of the charger based on your needs.
- Large motorcycles, small cars – These batteries will need more Amps to charge them up fast. Chargers in this range should have around 15-25 Amps to properly charge those types of batteries fast.
- Large cars, SUVs, Trucks, large boats, caravans – These are the most common type of vehicles in the USA and typically require an Amperage of around 30 Amps. That is why most companies offer their products in the 30 Amp range as well as with a low-amperage mode to trickle charge or Float charge after most of the fast-charging is done.
- Semi-trucks, campers – To charge these types of large vehicles fast, you will need a battery charger with more than 50 Amps.
Of course, if you decide that you don’t need to charge you battery quickly, you can always opt for a very low-Amp charger such as an 1.25-Amp one. Those might take a day or two to fully charge a large battery but some mechanics argue that this is healthier for the battery and increases its life expectancy. Most people prefer getting a charger with both trickle-charging and fast-charging options so they can choose between both depending on their need and their time-frame.
Diagnosing A Dead Car Battery
Car batteries are essential to almost all of the car’s components. Once the battery gives the engine its spark of life, the electrical side of things is taken over by the alternator. Still, without a good battery, our car can struggle to crank its engine and even start. There are different stages of a dying battery, though, and luckily there are a lot of symptoms that can point us to the cause of the issue and give us a hint at what we should be doing next…
Symptoms of a nearly dead battery
There are a few things that every car turns on before you get to the ignition stage. Those are the dom lights once you open the doors, the door chime when you insert the key in the ignition, the radio turning on before you startup, and so on. A nearly dead battery will immediately present itself by making all those features of the car appear weak and malfunctioning. The dom lights, for instance, will appear dimmer than usual if the battery is on its way out.
A slow engine crank can also be pointing to a nearly dead battery but that can also be caused by an array of other reasons.
Symptoms of a dead battery
You remember all those things we just mentioned about your car? Well, none of those will be happening if you’re dealing with a dead battery. Even your car’s alarm system can be turned completely off if your battery has no more juice left in it. The dom lights and any other electrically-powered interior feature won’t turn on upon your entry. This is a clear sign that something is really wrong with the battery. When you insert your key in the ignition and turn it, nothing will happen. Typically, a blown main fuse can cause all these issues or even a corroded battery connector. Turning on your headlights and them not working is typically a clear tell that any of those things is true.
Looking at the engine
Hearing your engine is one of the best ways to diagnose a dead or nearly-dead battery. If you turn the key in the ignition and nothing happens, then the most probable cause is a dead battery or a faulty starter motor. If you can hear everything preparing to crank the engine but the engine refuses to crank, a dead battery is unlikely.
Sometimes we can hear our engines barely wanting to crank up. While that can be due to a variety of reasons such as old spark plugs, old starter system, and so on, a common cause would be nearly dead battery that is on its death bed. The most proactive action in that scenario would be to slowly charge the battery up to 100% and leave it to trickle charge for a few more days (if possible). Fast-charging isn’t advisable in these occasions. You can charge your battery fast only if the battery is new and healthy and hasn’t been fully depleted prior to that.
Frequently Asked Questions
How Do I connect the car battery charger to my car?
You simply find where the battery is located in your car, remove the car’s connectors (a positive red one and a negative black one) and connect the alligator clips to the battery’s terminals. Make sure you connect them the opposite way of the disconnecting order. First the red one to the positive terminal and then the black one to the negative terminal of the battery.
How long should I charge my car’s battery?
How long you charge your car’s battery depends on the charging speed and the desired effect. Deep-cycle batteries need, on the average, longer charging times, while traditional AGM or other lead-acid batteries can be charged within 4-6 hours with a powerful enough charger. If you want to trickle charge your battery that would usually take more than a day but will ultimately increase the battery’s performance and longevity.
How fast will a charger charge my battery?
How fast a charger charges your battery depends on the charger’s current and your battery’s volume. A 100Ah battery can be typically charger well-within 6 hours if the charger works at 20-30 Amps. A low-amperage charger (2-10 Amps) will take longer to charge your battery even if it is a 30Ah one.
Can I charge my car’s battery while it’s connected to the vehicle?
No, you need to first disconnect the battery from the vehicle and then connect your charger to it. Otherwise, you risk damaging the car’s installation, the battery, and your charger.
Are solar battery chargers effective?
While solar battery chargers are effective for smaller lithium-ion batteries they are almost useless when it comes to big lead-acid batteries.
Finding the best car battery chargers is going to take a little prior research. Knowing the Amps at which a charger works, as well as its compatibility with different battery types, is typically enough for you to be able to filter out the better models. Don’t forget to take a look at the safety features of the models you’ve set your eyes on and make sure that it is well within your budget. If you are still struggling with your choice, I recommend going with one of our hand-picked models based on your car’s specifications and battery needs.