How to Use Marine Batteries in Properly

Published on: August 5, 2022
Written by Liam Jaxon / Fact-checked by David Rowan

This article describes how to use marine batteries on the property. All related information will help you to get knowledge about this sector.

Install a Marine Battery Selector Switch

Lock the wheels of your boat on the trailer. Disconnect the negative battery cable from the main trolling motor battery with a socket and a wrench. Choose a location for mounting the selector that is close to the battery as well as the excess wire will not be needed; Long wires from the dashboard location create too much resistance over time – keep the wiring short. Draw the outline of the mountain with a pencil on the inner plate of the transom or on the side rail.

how to use marine batteries in properly

Locate the (red) positive wire from the main trolling motor battery that goes to the starter relay or starter. Use a socket and a wrench to disconnect the starter cable or relay. Connect the starter wire with one to the number one post on the battery selector, using the washer and nut provided in the kit. Tighten with a socket and a wrench.

Trace (red) positive wire from the second battery to its source, which would be the additional connection on the positive lead of the main battery in the case of a parallel configuration. Loosen and remove the positive lead from the main battery with a socket and a wrench. Connect the other end of the positive second battery lead to the number two position on the battery selector, then tighten the kit nut and washer with one socket.

how to use marine batteries

Use the wire supplied in the kit to connect the third station on the selector to the starter or relay. If you do not have the appropriate caliber wire from the kit, refer to the owner’s manual for the appropriate wire size. Get the yarn from a marine feed store if it was not included in the kit. Cut a section of wire long enough to go from the third selector station to the starter or relay. Strip both ends of the wire with a wire stripper and crimp the two electric eyelets.

Connect one eyelet to the number of three posts and tighten the washer and the kit nut with one socket. Connect the other end of the eyelet to the starter relay or starter and tighten it with a socket. Route your wires in the most convenient and safe way that will lead to the selector switch.

Use the mounting screws in the kit to secure the switch from your predetermined location to the transom or rail hull. Use a Phillips screwdriver to tighten the self-tapping screws in the mounting selector. Reconnect the negative (black) battery cable to the main battery in the motor battery. Test the operation of the switch when you have the boat in the water and running.

Tips and Warnings

If you opt to secure your marine battery selector on the transom, you may need a drill and bits to complete the installation.

Make Marine Battery Cables

Marine battery cables carry starter loads and all 12-volt loads on board. The cables must be sized to carry the sum of the loads. Typically, the 00 gauge cable is used to ensure that loads are covered and minimum heating will occur in the cable. Use a cable that has many fine wires instead of some large ones. The finer wires will be more flexible and resist the tendency to break at the terminals due to the effects of vibrations.

Follow this Steps

Cut the red and black cables to the desired length with the cable cutters. Allow sufficient additional length for routing and strain relief at both ends.

3/4 inch insulation tape at the ends of the cable. Insert the stripped part of the cable into a terminal. Do not allow the tab to overlap the insulation on the cable. Place the tab into the crimp tab and strike firmly with the hammer until the tab is fully crimped on the cable.

Repeat step 2 for the other cable.

Treat the terminals with liquid electrical tape. Paint the tape over the insulation and the surface of the terminal that crimps the cable. This will protect the connections against corrosion. Do not paint the annular part of the terminals. Allow the liquid ribbon to dry completely.

How Often Should a Marine Battery Be Recharged

A marine battery should be recharged as soon as possible after use to prevent the battery from becoming deeply discharged, which can damage the battery and shorten its lifespan. The frequency of recharging will depend on how often the battery is used and how deeply it is discharged during use. A marine battery that is used frequently and discharged deeply may need to be recharged every day or every few days, while a marine battery that is used infrequently and only partially discharged may only need to be recharged once a month or less. It’s also important to regularly check the water level in the battery and to keep it topped up with distilled water as needed.

Marine Battery Test Procedures

Marine batteries, sometimes also referred to as deep discharge batteries, should be tested regularly so that they can be replaced before an emergency occurs. There is a series of tests that will provide a thorough evaluation of marine batteries.

Visual inspection

Most basic tests for regular inspection. Check the plastic battery case. If there are cracks, replace the battery immediately. Look at terminals and connections. Accumulation of heavy acid or corrosion is a warning sign. Check the electrolytic fluid levels while feeding up. This also provides a good opportunity to check other fluid levels.

Tension and Specific Gravity Tests

Voltage testing and density are two common ways to test marine batteries. Before you perform either, you must fully charge the battery. Cancellation Policy: If canceled up to 1 day before the date of arrival, no fee will be charged. Have a copy of the manufacturer’s specifications for the battery. If you have lost the features, you can find them online at the manufacturer’s website.

Use a voltmeter connected to the battery terminals to test the voltage. Refer to the datasheet to see how your battery measurements go up.

For the specific gravity test, you will need a single hydrometer. They are very inexpensive and available at any auto parts store. Press the bulb on the electrolyte from the battery. Take the reading and compare it to the datasheet.

A battery that fails one of these tests lives on borrowed time and must be replaced as soon as possible.

Load Tests

Perform a load test for batteries that pass the voltage and density tests but are not performing well. Load test devices are more sophisticated and expensive, take your battery to a battery retailer or automotive parts store that has a load tester.

As the name suggests, these machines test the battery as it is placed under a load. Although this type of test does not necessarily measure the capacity of the battery, it does or does not have the battery has an internal fault. A battery that fails this test must also be replaced.

Safety Tips

Each time you handle a marine battery, wear goggles, rubber gloves, an apron store, and old clothes. Fresh water and baking soda neutralize any acid spill

How to Connect a Battery in a Tandem

Unless you are a fisherman or you live on your boat, chances are your boat spends a lot of time on the dock. As a result, the batteries that power the engine tend to drain power, and right when you need to use your boat, the batteries do not have enough juice to turn the starter. One way to end this problem is to wire additional batteries in parallel, which will provide you with more amperage to run your equipment and make you less likely to have startup problems.

Connect a Battery

Place the second / or third battery in line with the stock battery in your boat, depending on how much space you have for the extra batteries. You want to align the positive and negative terminals on all batteries in the same orientation. This way, the wiring tracks will be shorter and easier.

Disconnect the positive and negative terminals of the batteries with your hands. Marine batteries have wingnuts to hold depressed terminals, so twisting them counterclockwise will allow you to remove the terminals properly.

Loop the battery cables from each terminal to the other. Meaning, you connect the positive terminal on one battery to the positive terminal on the next. Then fix each terminal down using the wingnut and your hands. When finished, the negative terminals of the two to three batteries will be connected with the wiring, and the same with the positive terminals.

Connect the positive lead for the boat to the positive terminal of the original battery and the negative lead for the boat to the negative lead of the original battery using your hands. The boat will now see a 12-volt charge on the first battery, but the intensity will be multiplied by the number of batteries in line.

What Precautions Should Be Taken When Connecting Multiple Marine Batteries Together

When connecting multiple marine batteries together, there are several precautions that should be taken to ensure safety and proper function.

  1. Make sure the batteries are of the same type and capacity. Mixing different types or capacities of batteries can cause damage to the batteries and the electrical system.
  2. Use the correct size wire for the connection. The wire should be of a sufficient gauge to handle the current flow without overheating or melting.
  3. Connect the batteries in parallel. This will keep the voltage the same across all the batteries but will increase the overall capacity of the system.
  4. Use appropriate terminals, lugs, and connectors to connect the batteries. These should be corrosion-resistant and properly sized for the wire being used.
  5. Be sure to use proper polarity when connecting the batteries. The positive terminal of one battery should be connected to the negative terminal of the other battery.
  6. Use a marine-grade battery switch to isolate the batteries from the electrical system when not in use, to prevent any unwanted discharge or overcharge.
  7. Monitor the battery voltage regularly, and charge the batteries as needed to ensure they maintain proper voltage levels.
  8. Lastly, it’s important to use approved safety gear when working with batteries, such as gloves, goggles, and other protective gear.

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About This Writer

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Hi, I am responsible for the 'Homeowners Power Solutions' category. My name is Liam Jaxon and a licensed technician with 7 years of experience in vehicle batteries, electrical gadgets, and home appliances. My working experience in different residential & light commercial electrical sectors and the automobile industry helped to acquire vast knowledge in this industry.

Hi, I am responsible for the 'Homeowners Power Solutions' category. My name is Liam Jaxon and a licensed technician with 7 years of experience in vehicle batteries, electrical gadgets, and home appliances. My working experience in different residential & light commercial electrical sectors and the automobile industry helped to acquire vast knowledge in this industry.

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