General Information on Batteries
A battery can simply be regarded as a storage vessel for electrical power. This implies you we are able to carry electrical energy from one place to another and use it anywhere we might need it, all thanks to the battery technology. This makes it a key player heavily relied upon by the system as a whole.
As a storage vessel, they provide a relatively steady source of energy during periods when your photovoltaic system is not producing power or when the grid is down. Batteries are predictable and stable enough for reliable long-term service although they are not 100 percent efficient.
While some batteries are able to store small amount of energy and also quickly discharge, others like the deep cycle battery are known to store larger energy and slowly discharge over a longer period. This simply properties makes them best for powering recreational vehicles, boats and to be used as backups in most systems. Also, in renewable energy systems that require the storage of huge quantity electrical energy, deep cycle batteries play a key role.
There are four main types of battery designs determined by the thickness of the lead plates. The thin plates less expensive design provide higher cranking power. Thicker plates more expensive ones have reduced cranking power, but longer discharge time. Generally, the thicker the plates, the longer the battery life and time it will take to discharge. As a rule of thumb, “starting” or “auto” batteries have the thinnest plates, whereas the highly expensive (and heavier) deep cycle industrial batteries have the thickest plates. “Hybrid” and “marine” batteries have plate thicknesses somewhere in the middle
Deep Cycle Marine Battery Review: Deep Cycle Battery
When we talk of battery in the context of renewable energy, we are mostly referring to the deep cycle batteries. Deep cycle battery gets its name from the ability to be discharged down to 20 percent and still be recharged (deep cycling) repeatedly without causing harm or damage to the battery. Deep cycle batteries are generally designed to have thicker plates and are used primarily in industrial applications as backup batteries, or in solar power plants, where extended discharge times are most important.
A deep cycle battery is an energy storage unit in which a chemical reaction occurs that produces electrical energy or electricity for short. These batteries are designed to be deeply discharged and recharged many times without damaging the battery hence the name Deep Cycle Battery.
A deep cycle battery is similar to a car battery in that they are lead acid battery, but they differ in many aspects. For example, while a car battery is designed to deliver a high burst of energy for a short time, a deep cycle battery provide a more constant (steady rate) charge or power over a long period and are thus commonly used with golf carts, motor homes, boats and other recreational vehicles.
While a starting battery has thinner plates and is more prone to warping and pitting when discharged, a deep cycle battery is designed with thicker plates, have less instant energy, but greater long-term energy delivery or discharge time. Their thicker plates make them capable of storing huge electrical energy (charge) and thus can survive a number of discharge cycles.
Deep cycle batteries after being heavily discharged over longer periods, recover fully. This is thanks to their thicker plates with a high content of antimony design features. When used overnight, their use might deplete about 50-70 percent of the battery capacity. The energy depletion rate largely depends on the house loads of the boat. This call for the need to recharge which again re-deposited energy into the bank, and the cycle, or process, starts over. Generally, the selected deep cycle batteries should be sized to store three to four times the expected amount of energy to be used between recharge cycles.
There are different types of deep cycle batteries such as AGM batteries (Absorbed Glass Mat), flooded batteries, gel batteries and recently lithium-ion. All of which are made differently.
The flooded battery is the most commonly used deep cycle battery. It is made up of lead acid similar to the standard lead acid battery in car batteries. The gel batteries, also famous has a gel-like substance in them while the AGM batteries consist of acid suspended in a glass mat separator. The next generation lithium-ion battery systems are projected to experience significant uptake among grid-connected and off-grid households in the future.
Deep Cycle Marine Battery Review: Deep Cycle Battery Ratings
They are basically two ways to rate batteries, volts and amps.
Amp hour (Ah) is the measure of the capacity of chemical energy available inside a battery that is converted into electrical energy. It also refers to as the discharge rate. The discharge rate is a measure of the time it takes to discharge a battery before it needs recharging. In other words it’s the amount of energy that the battery can store.
The capacity of the battery is reduced if the battery has a faster discharge rate or if it takes a shorter period, for instance over 1 hour to completely discharge. Thus, the amp hour capacity will be reduced by about 50% and so will the amount of cycles.
When a battery is discharged at a constant rate of current over many hours, it’s referred to as the “C” rating. For instance, many small batteries are rated at the C20 rate. This implies, the battery will deliver its amp hour capacity if discharged (in used) over 20 hours. Lager batteries in large stand-alone power systems are rated C100 rate meaning they are designed to discharge (used) over 100 hours or 4 days with a life span typically of about 15 years.
More recently, batteries for residential applications are often referred to by their kilowatt-hour (kWh) capacity.
Deep Cycle Battery Review: Discharge Cycles
Selecting the right battery for a particular use can be confusing. While all batteries claim to be particularly well suited to an energy storage purpose, all deep cycle batteries are not designed or created equal, even within their own type such as Gel, Sealed Lead Acid or AGM.
The goal of most deep cycle battery users is to select one that will last many years since purchasing a deep battery maybe quite an investment. The cycle rating is one of the best ways to determine a battery life span. This is the measure of the number of times a battery can be discharged and recharged during its life span. IEC 896-2 discharge cycle, based on a 100% discharge, is the best benchmark.
The IEC 896-2 provides a good baseline for drawing comparisons between different brands and also different battery lines from the same manufacturer although discharging a battery 100% is not recommended because it significantly decrease the life of any deep cycle battery.
Deep Cycle Marine Battery Review: Battery Charging
The battery sulfates or its performance and life span decreases if it’s not recharged thus charging a battery immediately after being used (discharged) is of almost important. Again, you won’t be able to reused it once discharge since it won’t also supply enough energy (if any at all) to drive the system.
The alternator, which is the battery charger, works well if battery is not deeply discharged. If an alternator is used to charge a deeply discharged battery, it tends to overcharge it which may intern damage the batteries. This is the more reason why they are never used to charge an engine-starting battery as they quickly destroy the battery, reducing it life span by about 50% each time they are charge with an alternator.
Deep cycle batteries are charge in a special way especially when they have been deeply discharged. This special type of charging is called 3-step regulated charging. Only special smart battery chargers using computer technology can perform 3-step charging techniques.
Step 1: Bulk Charging
This is where up to 80 percent of the battery energy capacity is replaced by the charger at the maximum current amp rating and voltage of the charger.
Step 2: Absorption Charge
This phase set in when the battery voltage reaches 14.4 volts. At this stage, voltage is kept constant at 14.4 volts and the current (amps) declines until the battery is 98% charged
Step 3: Float Step
The last step where the battery is fully (100%) charged or close to it. This is achieved by regulating the current at less than 1 amp and the voltage at not more than 13.4 volts. The float charge will not heat or boil batteries, but will maintain the batteries at 100% readiness and prevent cycling during long term inactivity.
Some AGM and gel cell batteries may require special settings or chargers for best charging.
Deep Cycle Marine Battery Review: Battery Testing
A battery can be tested in several ways with the most accurate method being the measurement of battery voltage and specific gravity. The battery voltage is measure with a digital D.C. Voltmeter and the specific gravity with a temperature-compensating hydrometer. A quality load tester may be good to test sealed batteries.
Before using any of the testing methods, start by getting the battery to full charge and then remove the surface charge. To surface charge is removed by discharging the battery for several minutes usually with the use of a headlight (high beam). After turning off the light, you’re ready to test the battery.
Another method of battery testing is Load testing. Load test removes amps (current) from a battery in much the same way as starting an engine would. You can get a load tester at most auto parts stores. A load test can only be performed on a battery that is near or at full charge.
Most battery companies label their battery with the amp load for testing. This number is generally half of the CCA rating. For example, a 400 CCA battery would load test at 200 amps for 15 seconds.
The following are some tips from the results of your testing:
Hydrometer readings should not vary more than 0.05 differences between cells.
Digital volt meters readings for the voltage should be as shown in this document. The gel cell and sealed AGM battery voltage at full charged will be slightly higher in the 12.8 to 12.9 range. A shorted cell is usually indicated by voltage meter voltage readings within 10.5 volt range.
The volt meter and load test are the only possible ways to test a maintenance-free wet cell. Maintenance-free batteries that come with a built in hydrometer (green/black window) generally give the condition of 1 of 6 cells. The problem with such reading is that, you may get a good reading from 1 cell but have a problem with other 5 cells in the battery.
Deep Cycle Marine Battery Review
Basically, a deep cycle marine battery referred to a deep cycle battery adapted to run marine engines and appliances like boats engine. The marine appliances running on such battery require power at very slower rate but for an extended period of time which can only be suitably provided for by a deep cycling battery. The best deep cycle marine battery has fewer but thicker lead plates than those of the cracking marine batteries. Thus, deep cycle batteries are specially manufacture to bear deep cycling (deep discharging and recharging cycles) necessary to power up the appliances for long period.
A marine deep cycle battery can also be used as a cranking battery to startup an engine, in which case the selected battery should have at least 20 percent higher power outing compared to the engine require power to be able to supply the needed cranking energy. In most cases, this is not so, thus the engine may not run at all that can be problematic if you are stuck at the water.
Types of Marine Deep Cycle Battery
There are different types of marine deep cycle that can be used to power boats and other recreational vehicles, each being different in design and construction. The reason for these differences is simply because they are used in different environments and thus they must withstand rough usages. This means that when choosing the best deep cycle marine battery for your requirement, you should be careful and pay attention to the details. These batteries are also slightly more expensive than others. That notwithstanding, they have a good number of advantages.
Among the most common and frequently used marine batteries is the flooded marine deep cycle battery. Their main drawback is with the case of a leakage which can damage the battery itself or damage the boat as well. Also, the most recommended flooded batteries are the 200 amps, because they offer a perfect money-value balance.
In order to prolong lifespan and for best performance, each deep cycle marine battery should be properly maintained. This simply means cleaning and protecting the cables and the terminals at least once per year as corrosion can compromise performance. You may also use heat-shrinking hoes in order to get the best protection.
Important also is the storage of your batteries. A boat battery must be properly stored and the best storage environment is in the garage or boatyard. Place it in a protective case, away from the elements and low/high temperatures. Bear in mind that extremely low or high temperatures can cause a battery to lose its charge and over a long period of time, this may lead to permanent damages.
Gel marine deep cycle battery may be a slightly better solution with its main benefit being its design and construction. This type of marine deep cycle battery is leak-proof, so they are much safer and can be used for a longer period of time. However, they are slightly more expensive and they can deliver less energy, which makes them not ideal for some boat.
Even the best deep cycle marine battery requires occasional recharging. Even if there are not used during the whole year, they must be recharged just to keep them in a perfect state. The best chargers to use are those that can deliver around 20 amps. If you are use those with 10 amps, its fine also, but they require more time to get the battery to full charge.
I actually still recommend gel deep cycle batteries, because they cannot leak nor can cause damage to the vessel.
How a Deep Cycle Marine Battery Works
A marine deep cycle battery is a high power, low maintenance solution for recreational boaters. However, it is vital to understand how they work and what types of behavior can render them vulnerable in order to maximize their potential for power.
The deep cycle marine battery is the sole mode of power backup and storage, not only for your boat, but also to run the various electronica appliances onboard. Their high used as backup and storage batteries in mainly due to the fact that, they are able to store huge electrical energy between their thick plates and only dissipate, release or discharge this energy at a slow rate. This also makes them not fit as cranking or starting batteries. Thus, for the best fishing and recreation experience, having the right marine battery is really important.
How to Trickle Charge a Deep Cycle Marine Battery
Trickle charging a marine battery is a technique of keeping your battery ready for immediate use during the summer months. It has two main functions;
It helps to make sure that your battery doesn't die in the middle of your journey (lake), leaving you stranded.
It’s also as a maintenance plan for the winter when you are storing your boat. The continual sending of electricity into the battery helps prolong its life and enhance its performance and efficiency.
To trickle charge a marine deep cycle battery, use a charger (which often has an electrical cord and two cables with clips on the end of them) and connect first, the black wire/clip to the negative (-) terminal and connect the red wire/clip to the positive (+) terminal of the battery. Then plug the battery charger into an electrical outlet. There is usually a red light on the charger that turns green when the battery is fully charged. When this light turns green, unplug the electrical cord from the wall and disconnect the charger battery terminals.
The best deep cycle marine battery charger is rated at 1.5 to 2 amps, meaning your battery is being given charges at the rate of 1.5 to 2 amps per hour. By providing a slow and low amperage charge, the battery's life will be maintained for a longer period of time and also prevent the battery from overheating. On the other hand, fast charging causes a high amount of heat generation, which can damage or destroy your battery by welding its internal plates together. In order to also prevent the battery or charger from overheating, avoid leaving the charger connected to the battery for more than 24 hours.
Overcharging and Undercharging
Either overcharging or undercharging a battery can have severe consequences, most of the time resulting in a destroyed battery. Overcharging a marine battery can cause it to overheat, which may reduce the life expectancy of the battery. By continually using an undercharged battery, a sulfur buildup (known as sulfation) occurs on the internal plates. Sulfation usually hardens and eventually disrupts recharging of the battery.
Immediately disconnect your batter or charger whenever they feel hot to touch. Over-heating may cause irreversible damages to your batteries.
There are onboard charges in the marine field. These chargers allow for a continuous trickle or slow charge to enter the battery during use. This is the best way in keeping the marine battery working for a long period of time. Solar powered trickle chargers are available and used during maintenance of the board and during regular use. Other trickle systems (mostly manual) can be carried on the boat, allowing a trickle charge during use. It’s best to always consider a waterproof battery charger in order to provide protection to the charger itself.
How to Add Water to a Deep Cycle Marine Battery
A lead-acid marine deep cycle battery is often found in operations where renewable energy batteries are in use. There are used in a variety of vehicles from recreational vehicles, golf carts to marine boats, and as backup power. Marine deep cycle batteries can be regularly deeply discharged and recharged without damage to the battery. Providing a marine deep cycle battery with the proper maintenance may not only double its life span but also keep its performance normal and trouble free for years.
Battery refilling is one of the more important procedures of the maintenance cycle. Check water level, the small square lead plate in each cell of your battery must completely submerged in liquid, and refill battery with distilled water as needed every six to 12 months.
In order to add water to a deep cycle marine batter, you will need the following:
- Deep-cycle battery
- Adjustable wrench
- Distilled water
You can then proceed with the process in the following steps:
Examine the battery for current water levels. Look to see the small square lead plate in each cell of your battery completely submerged in liquid. You may need to add distilled water to the cell if the level has dropped.
Examine the battery terminals to which the cables are connected to identify which is the negative terminal (marked by a "-" sign) and which is the positive terminal (marked by a "+" sign).
With the use of an adjustable wrench, disconnect the battery by removing any cables, loosening the bolts that hold the cable clamps in place, and then pulling the cable from the battery post. Start by disconnecting the negative cable and then the positive.
Unscrew and remove the fill cap on the top of the marine battery cell that needs refilling. Set aside this cap.
Carefully, with the aid of a rubber funnel, pour the distilled water into the battery, making sure the lead plate is completely submerge.
Fill lines are usually located about an inch from the top of the battery cell on the side of the battery housing; fill the battery cell to this marked fill line.
Screw the fill cap firmly back into place.
Reconnect the cables to the battery. Remember to start with the negative cable and then the positive.
How to Wire a Marine Battery Switch
Battery switches are an important safety device in recreational vehicles, motor racing cars and boats. The ability to shut off a battery in a boat can prevent dangerous attempts to start the motor in the event of a fuel leak in the engine compartment. In both recreational vehicles and boats, having a second battery to select can prevent being stranded when the main battery is discharged. Adding a battery switch is a good safety precaution for the do-it-yourself RVer or boater.
You’ll need the following to accomplish this task:
- Battery switch
- Battery cables
Start by disconnecting the negative cable from the battery.
Determine the best location for the battery switch. The position should be someplace easily accessed by the boat operator.
Install a second battery box for the second battery, if one is being installed.
Measure the distance from the main battery to the switch and get a battery cable of exactly this length.
Measure the distance from the secondary battery box to the switch and also get a battery cable of the measured length.
Get the distance from the secondary battery to the vehicle, or boat, ground connection and get a battery cable of this length.
Determine the distance from the battery switch to the terminal where the main battery's positive cable attaches to the solenoid or starter and also get a battery cable of this length.
Now, remove the positive cable from the main battery and starter or solenoid.
Install a cable from the positive end of the main battery to terminal one of the switch.
Repeat this process for the secondary battery.
Install the cable from the OUT terminal of the switch to the point on the starter or solenoid where the original positive cable from the main battery was attached.
Then attach the ground cable for the secondary battery to the battery and the chassis ground.
Turn off the battery switch.
Connect the main battery negative cable to the battery and you are ready to go.
Turn the switch knob to be able to select a battery to use.
Factors to Consider while Selecting a Deep Cycle Marine Battery
The deep cycle marine battery comes in different type, price, size, and features. Choosing the right marine battery may be a difficult task to most people. Below are some of the essential features of a deep cycle marine battery to help you get the best battery that fits your requirement.
Application or Purpose
This is the first and most important factor to consider before purchase any battery. What is your goal?
A deep cycle marine battery is usually used for two applications. That is, to power up various appliances and to starting the boat or other engines. According to your goal, you can select between Deep Cycle, Cranking (Starting) and Dual-purpose marine battery.
There are many rating to consider when choosing marine battery. These are the CA or MCA, CCA, RC and Amp hour.
Cold Cranking Amps (CCA) is the measure of the amps delivered in 30 seconds at 0°F in order to maintain voltage above 7.2 volts, which is also the least power required to start or crank an engine. Thus the CCA is used in determining the starting suitability. In a marine battery, it’s referred to marine cranking amps (MCA).
Marine Cranking Amps (MCA) is rating that is determined as the number of amps delivered in 30 seconds at 32°F while starting the engine. You must check the type of engine that you have and the recommended MCA for it and according to the requirement the battery can be decided. It’s always best to choose a battery that has equal to or more MCA rating than the recommended unit for your engine thus, if you need to start your boat during cold season, it will be better to choose a battery that has at least 500 CCA rating or more.
Reserve Capacity Rating
Also, if you are buying a marine deep cycle battery, you must consider the Reserve Capacity (RC) rating. RC rating is the number of minutes a battery can sustain a load of 25 amps at 80°F until it’s discharged to 10.5 volts. For instance, a battery with 300 minutes RC rating can last for five hours by operating a load of 25 amps. Mostly the high quality marine batteries have RC rating of 180 minutes and the low quality ones have around 35 minutes, with the average RC ratings ranging from 60 to 90 minutes.
Amp Hour (AH) Rating
The Amp Hour rating is another important factor in a deep cycle marine battery. It’s the number of amps a battery can deliver in a time period of 20 hours. For instance, a battery with 200 AH will deliver 10 amps per hour for 20 hours. It’s not possible that a 200 AH battery will fully deliver 200 amps. Thus, always choose the battery that has more amp hour rating than the actual amount required by you.
Size or Group
Marine batteries come in different groups. They are determined in sizes; for example, 24, 27, 31, 6D, 8D, etc. If you already have an old battery box, endeavors to purchase a battery which perfectly fits in the box. Also, make room for the ventilation system available in your boat. Don’t get large battery when you lack room.
Weight is a very important factor that you must consider when purchasing a marine battery. It’s obvious that you will be required to often move the battery in and out of the boat often, thus, choose the battery with average weight of 20 to 50 pounds to east this process. In case you don’t need to transport the unit quite regularly, then a battery of average weight around 70 to 80 pounds will do.
The battery is usually exposed to tremendous amount of constant vibrations constantly from the boats’ operating motor. Such vibration is the primary cause behind the damages done to the internal parts of most marine batteries. This vibration dislocates the inner cells, resulting in deterioration of the battery. For this reason, the best deep cycle marine battery manufacturing brands have designed batteries that are resistant to vibrations. Such vibration resistant batteries last a lot longer than their standard counterparts.
The compartment of the marine battery is not always in a horizontal position and also, running onboard may cause the boat to run at different angles. The best deep cycle marine battery has been designed to withstand different slightly vertical positions. Make sure to purchase battery that fit into the compartment. We-cell batteries are not recommended for any other complicated positions as there may be risk of acid spilling. AGM, gelled or lithium marine batteries can be placed virtually at any position except upside down.
This is another important selection factor. Most marine batteries come with different volts usually 12 volts, 18 volts or 24 volts.
The 12 volts battery is not capable of powering up singly thus buying it will mean buying a multiple of 12 volts batteries. 18 volts batteries are good but the power might also be too low. Most boats owners prefer 24 volts batteries as these are reliable and powerful. If your marine unit or boat has very less room for batteries then 24 volts battery the best choice.
Some marine batteries like the flooded marine batteries require a lot of maintenance like timely refilling of distilled water, routine inspection for acid spill and terminal corrosion check. Many users might find these maintenance tasks very annoying and time consuming. Most other marine batteries like the gel, AGM and lithium batteries require least maintenance and only external terminal check is necessary.
The price range varies widely with the variety of batteries. Although the best deep cycle marine battery is not always cheap, it’s not a guarantee that they will last more. It is up to your care and maintenance that decides the durability of the battery. Many low budget batteries are also of high quality and powerful as the high budget ones. Thus you should always go for the best battery that sorts your budget.
MFD and warranty
Manufacturing date of the battery can’t be left out. It’s important to cross check the date of manufacture before buying the battery. The MFD is always labeled on the battery. It’s best to always go for the ones that are fresh and never buy a battery which has MFD of more than 6 months from the day of purchase.
All the marine batteries offer some warranty period and warranty is a must. There are two types of warranty provided to buyers, a full-rated warranty and pro-rated warranty periods.
A full-rated warranty period offers the whole battery replacement for free if it fails before the warranty ends while pro-rated, offers just a percentage of the amount refunded for the unused period of warranty. Thus, you should be carefully while reviewing your warranty.
Battery Safety, Explosions and other Hazards
Most battery explosions are caused by the misuse or malfunction of a battery, such as short circuiting a battery or attempting to recharge a non-rechargeable battery.
Explosions often occur when a short circuit resulted to or generates very large currents. In addition, deep cycle batteries release hydrogen when they are overcharged. Normally the gas dissipates quickly but also easily be ignited by a nearby spark (e.g. when removing the jumper cables). On the other hand, hydrogen gas isn’t a problem with lithium-ion batteries.
By attempting to charge a battery beyond its electrical capacity (overcharging), may lead to a battery leakage, irreversible damage, or explosion of a deep cycle battery. Not only that, it may also cause damage to the electrical components in which the overcharged battery is used.
When a conventional battery (car starting battery) is recharged at an excessive rate, an explosive gas mixture of hydrogen and oxygen may be produced faster than it can escape from within the walls of the battery, leading to pressure build-up and the possibility of the battery case bursting (exploding).
In extreme cases, the acid may spray violently through the casing of the battery, cause severe injury.
Deep cycle batteries may also explosions in maintenance if the valves are blocked or fail. This cause pressure rise within the cells until maybe a short circuit ignites the hydrogen-oxygen mixture. The resulting explosions can cause severe injury. Such problems can be detected in most batteries if the battery feels hot to touch or if the sides appear swollen.
Battery Tips for Best Performance
The following tips are true for all battery types and should be regarded as the tool for best practise and improved battery performance, not forgetting your safety.
- Stay with one battery chemistry (gel, AGM or flooded). Each battery type requires specific charging voltages. Avoid the mixing battery types which can result in under- or over-charging. Also, its best practice to change all batteries at the same time.
- Regulate charge voltages based on battery acceptance and temperature (manually or automated) to maximize battery life and reduce charge time. Make sure the charging system is capable of generating sufficient amperage to charge battery banks efficiently. This means using an alternator with 25% to 40% as many amperes as the capacity of your entire battery bank.
- Keep batteries clean, cool and dry.
- Never mix new batteries with old ones in the same bank. This may seems like there would increase the resulting capacity, old batteries instead tend to pull down the new batteries to their deteriorated level.
- Regularly check terminal connectors to avoid loss of conductivity.
- To flooded lead acid batteries, add distilled water as needed and keep them charged.
- Clean corrosion with a paste of water and baking soda.
- Always wear safety glasses and gloves when working with batteries.
- A always disconnect the negative battery cable first then the positive.