Deep cycle batteries are a little different from normal batteries. Instead of providing a big burst of energy like a regular battery, a deep cycle battery is designed to provide a sustained source of power over a prolonged period of time. This kind of battery is most often used for marine purposes such as boats, and for RVs and campers, as well as for solar power storage.
They’re also designed to be safely discharged 80% or even more, at which point it will need to be charged. That said, while you can use a normal charger, a smart deep cycle battery charger comes with many benefits.
A deep cycle automatic battery charger allows for precise charging, so you don’t under or overcharge your battery. These smart chargers prevent permanent damage due to both undercharging and overcharging; they can prevent sulfation; some smart chargers can even recover totally dead deep cycle batteries, all of which a normal charger usually won’t do. At the end of the day, this all leads to a longer battery lifespan and money saved.
However, there are so many available smart or automatic battery chargers on the market at varying price levels from different brands, that choosing the right one can be a challenge, not to mention that you need to look for the proper size of charger.
Today I want to take you on a thorough investigation of how these deep cycle battery chargers work, how to choose the right one for your needs, and further below I have also reviewed a multitude of these chargers to help get you on the right path.
Top 7 Chargers for Deep Cycle Battery
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Top Choice
- Small size and suitable for Most Vehicles
- It's lightweight, fully automatic and easy to use
- Perfect for all lead-acid
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- Automatically detects battery sulfation
- It's not just a trickle charger, it's an advanced battery maintainer.
- Compatible with all types of vehicles
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- Complete 7-step Charging Program
- Multi-Protection
- Advanced Winter Charging Mode
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- Simple and practical to use
- Smart charging mode
- High compatibility
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- Intelligent Charging Mode
- Wide Application
- Multi-Protection
- Customized Design
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- Battery charger for cars, motorcycles, boats, and more
- Made of durable metal with a sleek black finish
- Compatible with lead acid and absorbed glass mat (AGM) type batteries
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- Charge and Maintain 12 and 24 Volt Batteries
- Advanced multi-phase charging process
- Soft Start Mode for severely depleted batteries
Deep Cycle Battery Charger Buyer’s Guide
Right now, I am going to help you find everything you need to know about these deep cycle battery chargers.
How Does a Battery Charger Work?
A normal battery charger works by supplying a constant or pulse DC power source to a battery being charged. In layman’s terms, a battery charger is a device that put electrical energy into a rechargeable battery by forcing an electric current through it.
Deep cycle battery chargers work a little differently, particularly the smart versions. A deep cycle battery charger goes through at least 3 essential stages and jobs that they perform. Some advanced chargers such as Noco Genius Chargers even consist of 8 stages. These chargers are designed to charge a battery, to optimize the rate of charging, and to stop once the battery has reached full capacity.
In terms of stages of charging, the first stage is known as the bulk charge. This is when the highest voltage and amperage is used. This is when about 80% of the battery is charged in a limited amount of time.
The second stage involves the absorption charge. This is when the charger slows down while charging the remaining 20% of the battery. This is a bit slower than the first 80%, but due to the slower charging time, it helps prevent overheating and overcharging.
The third and final stage is known as the float charge, which usually starts when the battery is 90% or 95% full. Here, once again, the amperage of the charger decreases in order to bring the battery to full capacity without causing damage to it.
What is Charging Time?
Battery charging time is how long it takes for the active chemicals inside of the battery to be reconstituted while the temperature of the cell is kept at a safe level. The battery charging process is complete once the termination voltage has been achieved (in order to prevent overcharging).
How to Choose the Right Battery Charger
When I first started using deep cycle batteries and their respective chargers, I had a lot of issues finding the right one. There are lots of factors to consider and technical terms to be familiar with. I’ll run down a list of the most important things you need to consider when making a purchase.
Supported Battery Types
The first thing that you have to wrap your head around is that there are different types of deep cell batteries, and the charger you get needs to support the type of battery you have. For instance, if you have a lead acid battery, you will need a lead acid battery charger.
However, quite conveniently, most deep cycle battery chargers will work for most or all types of batteries. This includes lead acid, lithium ion, gel, flood, and AGM deep cycle batteries. Keep in mind that most smart chargers are compatible with all gel, flood, and AGM batteries. That said, before buying, ensure that your battery type is supported.
Voltage
The next thing that you need to consider is how many volts it is rated at. The most common voltages for these deep cycle battery chargers are 6, 12, and 24 volts, but there are also larger ones.
If you have a 12 volt battery (for example), it actually needs to be charged to around 14.5 volts to be considered fully charged, whereas anything under 12 volts means the battery is very depleted.
Simply put, you need a deep cycle battery charger which is specifically designed to charge the battery you have (in terms of voltage). You can’t use a 6 volt charger on a 24 volt battery, etc.
Charging Time – How long does it take?
The next thing you need to consider is the charging time, and this has to do with the amps. Generally speaking, the higher the amperage rating of the charger, the faster the connected battery will charge. However, there is a limit on how high you can go.
The amps of the charger in question should not exceed the total Ah or amp hours of the battery itself. As an example, a 100 Ah battery should be connected to a deep cycle charger that is has no more than 30 amps behind it.
If the charger has too many amps for the respective battery, you will start running into problems. For example, if you have a 100 Ah battery and a 3 amp charger, to get it from 0% to 100%, it would take somewhere over 30 hours. If time is crucial to you, I suggest you should calculate battery charging time first.
Battery Maintenance Feature
Something else to consider is that you get a charger with a battery maintenance feature. This is a feature which allows you to keep the battery connected to the charger even when the battery is full.
Simply put, a charger with this feature will turn off when the battery is full, keep track of the charge, and once the charge level of the battery drops below a certain level, the charger will activate once again. This is a great feature because it allows batteries to stay topped off at all times without fear of overcharging.
Length of Manufacturer Warranty
Another consideration is the length of the manufacturer’s warranty and how comprehensive it is.
Of course, depending on the quality of the charger, the price you paid for it, and the brand name, the warranties can greatly differ. The more comprehensive the warranty is, and the longer it is active for, the better off you will be if there is some sort of defect.
I want to say that you get what you pay for, and if you expect to get a quality item with a good warranty, you will have to invest a little extra.
Technical Support
It is also wise if you go with a deep cycle charger from a brand name or retailer that is known for providing top-notch technical support. These things can be complicated and confusing, so having support just a phone call or email away that can help get you back on the right track is a bonus.
How to Determine the Right Size of Battery Charger
Before you start looking at various chargers, you need to know the right size of charger for your battery. The size of the deep cycle battery charger you require is going to depend mostly on the type of battery that you have.
Remember that there are many different kinds of deep cycle batteries, such as flooded, AGM, and more. Let’s take a quick look at how to determine the size of charger you require based on the type of battery you have.
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For an AGM deep cycle batteries, the size of the charger can be up to 30% of the maximum capacity or size of the battery. As an example, a 100 amp AGM battery could handle a charger of up to 30 amps
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See Also: How to Size Battery Bank for Solar Panel
Best Deep Cycle Battery Charger Round-Up Reviews
Here I have a selection of 9 deep cycle battery chargers that I will be reviewing. One of them might be right for you.1. Foval Automatic Trickle Battery Charger
This is a very simple battery charger known as a trickle charger. This charger can be used for all sorts of deep cycle batteries including lead acid, flooded, AGM, and gel cell batteries. The Foval Automatic Trickle Battery Charger is ideal for virtually 12 volt batteries, particularly for automotive purposes.
It should work with cars, golf carts, boats, airplanes, and everything in between. Keep in mind that this charger has 4 stages, including initialization, bulk charge, absorption mode, and float mode.
What is convenient about this charger is that it is very small and lightweight which makes it portable and easy to store. To let you know what the state of the charge is, the Foval Automatic Trickle Battery Charger comes with LED indicators, which also provides information about diagnostics. This charger comes with a maintenance feature as well.
Features
- Support all lead-acid including flooded and sealed (AGM and GEL) batteries.
- State-of-charge LEDs to indicate when it's fully charged or in maintenance mode.
- Over temperature, overload, low voltage and high voltage protection.
- Reverse polarity hook up protected.
- Automatically switch to maintenance mode (floating charge) when fully charged.
- Well built sturdy design
- Very Affordable price for 1A charger
- Small and light weight
- Two years manufacturer warranty
- Not supporting Lithium-Ion battery
- Only have 4 charging phases
- Slow charging time for battery larger than 100Ah.
2. Schumacher SP1296 Fully Automatic Battery Charger
The Schumacher SP1296 is a 2A battery charger with a maintenance feature. This means that it can charge batteries quite quickly, and due to the maintenance feature, it can also maintain a full battery charge without causing damage to the battery.
What is really nice is that the Schumacher SP1296 is controlled by a microprocessor with multi-stage charging. It can easily detect how much charge the battery has and what type of charging the charger needs to engage in, whether bulk, absorption, float, or otherwise.
Keep in mind that the float mode helps ensure a maximum battery charge. What’s also cool here is that the Schumacher SP1296 can charge both 6V and 12V batteries, plus it works for standard, AGM, and other deep cycle batteries. There are also a number of safety features such as reverse hookup and voltage detection.
Features
- Support standard lead-acid, AGM and Gel batteries
- Charging status LEDs to indicate stage of charge
- Automatic 6V /12V voltage detection
- Reverse polarity hook-up protection
- Affordable price for a 2A charger
- Bright battery charging status LEDs.
- Two years manufacturer warranty
- Not supporting Lithium-Ion battery
- Slow for battery larger than 100Ah
3. NOCO Genius G3500 6V/12V Battery Charger
In case you haven’t noticed, we are constantly moving up to more powerful units, as this one is a 3.5A charger and maintainer. The NOCO Genius G3500 is an extremely versatile unit, as it can handle both 6V and 12V batteries.
It is ideal for use with lead acid, wet, gel, and flooded batteries, as well as common marine, deep cycle, automotive, and maintenance-free batteries. This unit even comes with an optimized charge mode to safely charge and maintain 12V lithium-ion batteries.
The NOCO Genius G3500 comes with a so-called advanced repair mode which can help repair and charge batteries that have not been charged for an extended period of time. This unit also features reverse polarity protection, spark proof tech, and other safety features too. It is fully automatic, so all you have to do is connect it to your battery.
Features
- Work with wet, gel and AGM lead acid, deep cycle, and lithium-ion batteries
- Feature protection against over-charge, over-current, over-heat, and reverse polarity
- Backed by 5-year warranty
- Automatically switch to maintenance mode when fully charged
- Support lead acid and Li-Ion batteries
- Well built sturdy design
- 4 visual LEDs to show state-of-charge
- 5 years manufacturer warranty
- Not showing charging voltage
- Comes with non SAE connectors
4. AIMTOM Smart Battery Charger 4 Amp 6/12V Fully Automatic Maintainer
Something I want to mention is that the AIMTOM Smart Battery Charger has a high waterproof rating and a snow mode for extreme weather operation. As far as I can see, it’s one of the more durable options available. Keep in mind that it’s a 4 amp charger, so it is getting up there in power.
What is impressive about the AIMTOM Smart Battery Charger is that it can accommodate both 6V and 12V batteries. Moreover, it works with all sorts of battery types including SLA, et, MF, Gel, Flooded, VRLA, AGM, EFB, LIFEPO4, and lithium ion, and can therefore be used for a wide variety of applications.
It also comes with a 24/7 battery maintainer feature to allow batteries to remain fully charged without fear of damage. Speaking of safety features, the AIMTOM Smart Battery Charger comes with reverse polarity, over voltage, overload, overcharge, and over temperature protections. It comes with a simple LCD display to view all of the info you need access to, and it’s quite practical as a whole.
Features
- Work with SLA, wet, flooded, gel, VRLA, AGM, LiFePO4 and lithium-ion batteries
- Feature reverse-polarity, over-voltage, over-charge, and over-temperature protections
- Sturdy design with IP65 waterproof, ready to use in extreme outdoor condition
- Auto sulfated batteries detection and repair mode
- Switch to maintenance mode automatically when fully charged
- Very affordable price
- Well-built sturdy design with back-lit display
- Work with lead-acid and lithium-ion batteries with IP65 waterproof
- Smart 8-stage charging process
- Mode selection button is too stiff
- Lightweight clamps
5. Battery Tender 5 Amp, 12V Battery Charger, Battery Maintainer
Going up the list, this is a 5 amp battery charger and maintainer that is ideal for 12 volt batteries and a wide variety of deep cycle battery types. To be exact, the Battery Tender can be used with lead acid, flooded, and sealed maintenance-free batteries.
It can quickly charge batteries, but it is also ideal for maintaining a full charge while a battery is not in use, something that the maintenance features makes sure of. The Battery Tender itself barely needs any maintenance.
The Battery Tender has a two-color LED light that indicate the charging status of the battery and if the voltage drops too much. There are 4 charging stages, including initialization, bulk, absorption, and float. It’s also worth mentioning that this unit comes with a 5-year warranty.
Features
- Work with standard lead-acid including flooded, sealed, AGM, and gel batteries
- Feature reverse-polarity, short-circuit protection, and spark proof
- Switch to maintenance mode automatically after fully charged
- Agency approvals: UL/CSA/BC
- Great customer support
- Well built sturdy design.
- Come with 5-year warranty
- No de-sulphation feature
- Only has 4-stage charging process
6. ADPOW 5A 12V Automatic Smart Battery Charger Automotive Maintainer
Right off the bat, something worth mentioning is that this charger comes with DC adaptors, as well as a limited quality warranty, and even a 30-day money back guarantee in case you are not happy with it.
This is a 5A charger, so it has a moderate amount of power, and it is designed to work specifically with 12V batteries. This unit is compatible with a wide variety of battery types including Pb, SLA, Gel, AGM, VRLA, wet, flooded, and sealed lead acid. Moreover, it is compatible with lawnmowers, boats, cars, electric vehicles, and more.
This unit comes with safety features including short circuit, overload, reverse polarity, and several others. What’s neat is that this is a 7-stage charger. The stages include desulfation, soft start, bulk charge, absorption, test mode, recondition, and float.
Features
- Work with SLA, Gel, VRLA. wet, flooded, AGM, and sealed lead-acid batteries
- Smart 7-stage charging process
- Protect against short circuit, overcharge, overheat, and reverse polarity
- Automatically switch to float mode after fully charged
- Able to re-condition drained batteries
- Well built sturdy and compact design
- Bright battery charging status LEDs
- Able to charge drained battery
- User manual is hard to follow
- Print on the label is too small
7. Clore Automotive PL2410 Battery Charger
If you need a big charger for big batteries, this Clore Automotive PL2410 Battery Charger might be right for you, as it can handle both 12-and 24-volt batteries. This unit is also quite impressive as it can handle lead acid batteries including flooded, AGM, gel, spiral wound, marine, and deep cycle batteries.
One of the coolest features of the Clore Automotive PL2410 Battery Charger is that it has a reconditioning mode that can bring a battery back to life after being distressed or drained too far.
The enhanced maintenance mode is another great feature as it allows for long-term storage. Also, keep in mind that this unit features 2, 6, and 10 A charging rates, plus it also comes with all of the necessary safety features.
Features
- Work with standard 12/24 volt lead-acid, flooded, Gel, deep cycle and AGM batteries
- Soft start mode for severely drained batteries
- Automatically re-condition a battery when sulfation is detected
- Enter float mode automatically after your battery is fully charged
- Protect against reverse polarity
- Charge severely discharged/dead battery
- Compact and light weight
- Large digital charge indicator
- Doesn't support lithium-ion battery
- It doesn't maintain or trickle charge
- Not meant for commerical use
8. Tower Top Smart Battery Charger 2/8/15A
What is super neat about the Tower Top Smart Battery Charger is that the amps can be adjusted to meet your needs. You can set this unit to 2, 8, and 15 amps, which makes this unit versatile. It will automatically detect the correct voltage as well, thus making it very simple to operate.
Moreover, the Tower Top Smart Battery Charger is designed for 12-volt batteries, specifically for lead acid batteries including Gel, AGM, and STD. However, be aware that this unit cannot be used for batteries drained below 3 volts.
This charger features a 7-step charging program. These steps include Desulfation, soft start, bulk charge, absorption, battery test, recondition, and float. The Tower Top also comes with safety features including over voltage, overheat, short circuit, and reverse polarity protection.
Features
- Work with 12V standard lead-acid, Gel, and AGM batteries
- Re-condition battery when sulfation is detected
- Advanced "Winter Charging Mode" to charge battery at -4°F / -20°C
- Protect against over-voltage, over-heat, over-charge, short circuit, and reverse polarity
- LCD display for charging status, charging current/voltage and error info.
- Built-in cooling fan
- Very reasonable price
- Built-in cable storage organizer
- Manual battery re-condition option
- User manual is thin
- Doesn't charge a battery below 3 volts
- Doesn't support lithium-ion battery
9. Schumacher SC1308 6/12V Fully Automatic Battery Charger
When it comes to a high power charger that you can use to start an engine, this Schumacher model is up there with the best of them. It comes with a basic 30A charging mode, which is already very powerful, as well as a 100A engine starter mode which can be used to start pickups, SUVs, and more.
The Schumacher has an auto-detection mode which will automatically detect whether you are using a 6V or 12V battery, and this charger is compatible with both of those voltages. What’s also neat is that this unit comes with a battery and alternator tester with an easy-to-read display. It comes with reverse hookup and other protections as well.
Features
- Work with standard 6/12V sealed lead-acid, deep cycle and AGM batteries
- Microprocessor controlled with float mode to charge and maintain automatically
- Powerful 30 / 100A engine starter
- Protect against reverse polarity hook-up
- Well built sturdy design
- Affordable price
- 100A engine starter for jump start
- Built-in cable organizer
- Clamps are a bit weak
- Doesn't support lithium-ion battery
Conclusion
I know that choosing the best deep cycle battery charger for your needs can be a difficult task, and even just figuring out what your needs are in the first place can be quite the challenge.
The most important factors to keep in mind are that the charger needs to have the right amperage; it needs to be compatible with the specific battery type; and it needs to be compatible with the specific battery voltage.
Something that I want to make clear is that deep cycle chargers and all related equipment are of course electrical in nature, and electricity comes with certain risks. Therefore, always take all safety precautions possible. Furthermore, if you don’t know what you are doing, it might be best to ask a professional technician for assistance. There is no shame in asking for help if it makes the difference between a proper hookup and a broken battery or worse.
Thank you very much to the writer for writing this informative article. This article can be very helpful for choosing the best deep cycle battery charger that we needed.