Deep cycle batteries are designed to provide sustained sources of power that can last over extended periods.
Smart battery chargers can now prevent permanent damage occurring from undercharging and overcharging batteries. Batteries can be safely discharged to 80% or more, and it is at this stage they need to be charged again.
As part of your battery maintenance, you could notice many smart or automatic deep cycle battery chargers on the market.
Many vary between deep cycle battery charger brands from manufacturers, as does the range of prices. Selecting the right one can be a challenge, as can picking the right one to meet your battery charging needs.
The best deep cycle automatic battery charger allows you to have precise charging, making sure you don’t undercharge your battery. (Find the Best RV Surge Protector)
By the end of our deep cycle battery charger reviews, you’ll know more about the types of deep cycle battery chargers and which is the best for your needs and your budget.
Why You Need a Good Deep Cycle Battery Charger?
Deep cycle batteries provide a controlled flow of power, delivering power for significantly longer periods of time. To charge such batteries, you’ll need a special type of battery charger, such as a deep cycle battery charger.
Here are a few reasons you need a deep cycle battery charger:
Battery Monitor: Any suitable deep cycle battery chargers should monitor the condition of your battery during charging. With this, you can monitor specific parameters of your battery, so you’ll know it is in the perfect state and optimal condition.
Battery Equalizing: When you see the equalizing feature on your deep cycle battery charger, it enables you to balance the battery’s charge and make sure it delivers sufficient power output for the expected duration. It can also reverse any effect of sulfation on your batteries.
Capacity: When you charge any large capacity battery, you’ll need a suitably large deep cycle battery charger. To properly charge, your charger needs to deliver a sufficient amount of input to your battery. Once the capacity of your charger increases, you can discover your amount of charging time decreases.
You can find many times you need such a charger. These can vary from chargers for trolling motor batteries or too large capacity batteries; you’ll need a high-performance RV battery charger. (Learn How To Protect Outdoor Extension Cord From Rain)
Top Deep Cycle Battery Charger Reviews
1. Battery Tender Plus 12V Battery Charger and Maintainer: 1.25 AMP Powersport Battery Charger and Maintainer for Motorcycles, ATVs, UTVs – Smart 12 Volt Automatic Float Charger
- Dimensions: 4.75 x 2.75 x 2.75 Inches
- Weight: 4.3 Pounds
- Voltage: 12V
- Ampere: 1.25 Amp
Many RVers, hold the Battery Tender Plus 021-0128 in high regard. The 021-0128 holds deep cycle batteries at full charge without fear of overcharging, where it switches to float mode when maximum capacity is reached. Furthermore, Battery Tender’s battery charger has superior temperature compensation, ensuring its charging is constant irrespective of air temperature.
- The setup process is straightforward
- Dependable and reliable
- Outstanding resistance
- Portable and lightweight
- Small battery clamps
- It can become hot on large batteries
With a guide price of just under $80, you get a lot of 12v deep cycle battery charger for your money. It’s easy to spot the stage of charge thanks to the colored LED lights. Additionally, if the battery voltage falls under a set threshold under load, the Battery Tender high-voltage model defaults to ISM adaptive charging to restore maximum performance.
Battery Tender offers a ten-year guarantee on its product, and you can see why the Plus 021-0128 is the best deep cycle battery charger for the money.
2. BLACK+DECKER BM3B Fully Automatic 6V/12V Battery Charger/Maintainer with Cable Clamps and O-Ring Terminals
- Dimensions: 8.00 x 3.00 x 2.00 Inches
- Weight: 1.2 Pounds
- Voltage: 6 &12V
- Ampere: 1.5Amp
The housing of BM3B is made from strong, durable plastic. It’s very light yet can deal with a few physical shocks and bangs. The small choice of best deep cycle marine battery charger comes with mounting brackets, and it is easy to set up the Black & Decker.
Black and Decker are among the largest names in power tools, and you’ll find this flows over to their chargers. The BM3B offers RVing enthusiasts two methods of connectors, like the battery clips and O-ring terminals. Because of this, you can quickly match the BM3B to the battery bank of your rig.
Like other chargers from the brand, this mighty battery charger offers low voltage compensation and can make up for voltage loss during use. The BM3B can still deliver full-rated charges when connected to deep cycle batteries via an extension cord.
- Very Economical
- Tiny and portable
- Durable build quality
- Circuit protection against overcharging, reverse polarity, or short circuit
- Poor owner’s manual
- Users’ reports of rusted parts
Despite its low guide price of just over $20, you’ll find plenty of features in the Black+Decker BM3B not available on some other costlier chargers.
B&D has engineered in a voltage selector for 6V and 12V batteries, and the charger automatically switches to float charge when it senses a full battery charge. It is easy to see the Black+Decker BM3B scores in our deep cycle battery charger reviews.
3. Battery Tender 5-Bank Charger: Selectable 6V /, 4 Amp Automotive 12V Battery Charger with 5 Banks – Smart and Switchable Multi-Bank 12V Battery Charger and Maintainer Station – 021-0133-DL-WH
- Dimensions: 18 x 9 x 12 Inches
- Weight: 13.1 Pounds
- Voltage: 6V & 12V
- Ampere: 4 Amp on 5 banks
The 5 bank charger from Battery render can keep five 6 or 12-volt car batteries charged without the risk of overcharging.
This is the first fully automatic, constant-current charger designed to power starter batteries on vehicles like SUVs, pickup trucks, and boats. Once batteries are at full battery capacity, the charger can automatically change to float for the maintenance phase of charging.
Using innovative battery management system technology, you can automate your vehicle’s charge by completely charging your battery, where it will then sit in float mode.
Also, microchip circuitry stops output voltage until clips are correctly connected to your battery, thus preventing dead-short sparking.
- The setup process is straightforward
- Dependable and reliable. Can be left unattended
- Quick connection harnesses
- Charges 5 batteries at once
- Short output wires
- Clips are not insulated
With a guide price of just under $800, it is a costly option. Yet, if you have a multi-battery solution you need controlling, there isn’t any other solution that can maintain battery life on several batteries at once.
4. Schumacher SC1281 100 Amp 30 Amp 6V/12V Fully Automatic Smart Battery Charger 100A Engine Starter and 30A Boost Maintainer and Auto Desulfator Advanced Diagnostic Testing
- Dimensions: 7.25 × 10.75 × 11.13 Inches
- Weight: 12.65 Pounds
- Voltage: 6V & 12V
- Ampere: 6/2Amp (continuous), and also a 30/100 Amp (boost for jump-start)
Since there is a microprocessor to control power output, the Schumacher SC1281 optimizes charging time and will keep your batteries charged simultaneously. The SC1281 excels at increasing battery bank lifetime thanks to the multi-stage charging mechanism.
As a result, the Schumacher charger is known as the best deep cycle battery charger for anyone wanting battery honesty. The charger can keep batteries in the best condition before they need replacing.
The Schumacher charger can deal with multiple types and charges AGM batteries, gel, and charge a deep cycle battery. Besides this, it is compatible with most recreational vehicle batteries.
You will discover the SC1281 sits perfectly with many battery banks that contain several battery types. In addition, it can detect 6V and 12V batteries once they are connected before the charging process starts. For safety, should you connect the charger with reverse polarity of clamps are on the wrong way, the charger won’t start charging.
- Very Versatile
- Great performance to features
- Easy to use controls
- The microprocessor-controlled system automatically adjusts amperage
- Users report loose parts upon receipt
- Battery readings may not be accurate
With a rough guide price of just under $80, The Schumacher SE SC1281 gets lots of positive feedback from many deep cycle battery charger sources because of the ease of use, yet the way it delivers high performance. It offers users a simple LED display and also a start or stop push button.
5. Optima 150-40000 Digital 400 12V Performance Maintainer and Battery Charger
- Dimensions: 7.10 x 3.90 x 2.70 Inches
- Weight: 5.0 lbs
- Voltage: 12 Volt
- Ampere: 4 Amp
If you need portability for your deep cycle battery chargers, then you’ll discover the Optima Digital 400 is a fantastic choice.
The Optima deep cycle battery charger uses a lightweight, space-saving design, which means you can quickly place it in the tightest of spaces. The Digital 400 has a flexible hook and tilt stand so that you can use countless battery configurations.
The charger uses a microprocessor for intelligent charging, and the Digital 400 optimizes charging current and improves battery efficiency.
As the Optima battery charger offers advanced spark, reverse polarity, and overcharging protection, it comes with a long-standing safety record. The Optima Digital 400’s control interface has a flush LCD monitor with many built-in indicators for charging statuses.
- Decent manufacturer warranty
- Fast recharging of batteries
- Straightforward installation
- Works as a motorbike battery charger, marine battery charger, or an AGM battery charger
- Shipping needs improving
With a guide price of just under $100, it is on the more expensive side, yet its performance sets it apart from many other smart battery charger options.
The Digital 400 4-amp battery charger is a good purchase if your budget can stretch this far. Also, as proof of the manufacturer’s confidence, Optima backs their deep cycle charger with a three-year warranty.
Best Deep Cycle Battery Chargers Buying guide
To decide on the right automatic battery charger, you need to know a bit more about what varies on them and how they work.
How Does a Battery Charger Work?
Normal battery chargers work by supplying constant or pulses of DC power to a battery being charged. In the basic method, a battery charger is a device that puts electrical energy into rechargeable batteries by forcing electric currents through them.
Deep cycle battery chargers go through at least 3 essential stages and functions they perform. Some advanced chargers like the Noco Genius Gen 1 Chargers can go through 8 stages of operation.
These chargers are designed to charge a battery, optimize the rate of charging, and stop once the battery has reached full capacity.
- The first stage is known as the bulk phase charge. This is when the highest voltage and amperage are used to charge the battery.
- In the second stage or during the absorption charge, the charger slows down while charging the remaining 20% of the battery to prevent overheating and overcharging.
- The float charge is used when the battery is 90% or 95% full.
What is Charging Time?
The time it takes for the active chemicals inside the battery to be reconstituted while the cell’s temperature is maintained at a healthy level is referred to as battery charging. If the termination voltage is reached, the battery charging phase is complete.
Battery Type Support
The first thing you must understand is that there are many kinds of deep cell batteries, and the charger you purchase must be compatible with the type of battery you have.
Many deep cycle battery chargers can function for many or most types of batteries. Deep cycle batteries such as lead-acid, lithium-ion, gel batteries, flood, and AGM fall into this category.
Bear in mind that most smart chargers work with gel batteries, flood, and AGM. However, before you buy, double-check your battery form is sponsored.
The next thing to think about how many volts it must be rated for. The far more typical voltages of deep cycle battery chargers are 6, 12, and 24 volts, although larger voltages are possible.
A 12-volt battery, for example, must be charged to about 14.5 volts to be regarded as fully charged, while anything below 12 volts implies the battery is severely depleted.
Put bluntly; you’ll need to have a deep cycle battery charger made to charge the type of battery you have for the voltage. For instance, you can’t charge a 24-volt battery with a 6-volt charger.
How Long is Charging Time?
The charging process time is related to the amps and a factor to consider. The higher the charger’s amperage value, the faster the attached battery can charge. There is, however, a limit to how much you can charge.
The charger’s amps should not be greater than the total Ah or amp-hours of the battery. A 100 Ah battery, for example, can be charged with a deep cycle charger that draws no more than 30 amps.
You will have issues if the charger has far too many amps for the battery. For instance, if you have a 100 Ah battery and a 3-amp charger, it will take more than 30 hours to charge it from 0% to 100%.
Another thing to think about is getting a charger with a battery maintenance option. This feature allows you to keep the battery attached to the charger even when it is fully charged.
Simply put, a charger with this feature can switch off when the battery is full, keep track of the charge, and start again when the battery’s charge level drops below a certain level.
This is a fantastic feature because it ensures that batteries are kept fully charged at all times without the risk of overcharging.
Another factor to remember is the duration and scope of the manufacturer’s warranty. Of course, warranties vary greatly depending on the charger’s consistency, the price you paid for it, and the charger brands you selected.
If there is a flaw, the more comprehensive the warranty is and the longer it is active, the better off you will be.
It’s also a good idea to buy a deep cycle charger from a reputable brand or store with excellent technical support. These things can be complicated and frustrating, so having support available via phone or email to help you get back on track is a huge plus.
The main concerns for deep cycle battery chargers are much the same as a car battery charger. Safety features are vital, as, with lead-acid batteries, these can get warm during charging. If the charger doesn’t cut out once the battery is charged, it can cause accidents.
Besides this, there will be lots of electricity flowing through these chargers, so a smart charger for deep cycle batteries needs to monitor their own temperatures and halt the charging process if they get too hot.
You can find some chargers that come with a cooling fan while others don’t, so these may require positioning in cool areas. (Read Do RVs Have to Stop at Weigh Stations?)
In testing, all the chargers performed admirably. Yet, it was clear the Battery Tender Plus 12V Battery Charger and Maintainer: 1.25 AMP Powersport Battery Charger and Maintainer for Motorcycles, ATVs, UTVs – Smart 12 Volt Automatic Float Charger was coming out on top.
It catered for more battery types than other chargers can maintain these, as well as any battery charger with repair mode, could do.
It comes with all the features and size to sit out of the way unnoticed. Besides this, it offers a lot without breaking the bank. For the money, it is the best battery charger and maintainer you can find.