Common Marine Battery Issues

by | Feb 26, 2016 | Business

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When a boat is running smoothly, it is a pleasure to operate and everyone has fun. However, from time to time, problems may develop with the electrical system and it may concern one of the batteries. Here are some helpful tips for dealing with these issues, and hopefully avoiding a lot of headaches.

Insufficient Power

If you have more than one battery wired in parallel, the first thing to do is determine which battery is the problem. This means you need to disconnect the power from each of them. Some cables will be easier to work with than others. For example, number 8 AWG cable is relatively flexible, while 2 AWG marine battery cable is stiffer. 4/0 cable is much bigger, extremely stiff and may require more effort to uninstall and install.

If you have a battery health tester, it will be useful. However, this only works when you are checking batteries with a full charge. Instead, it’s best to use a multi-meter. A 12-volt battery should have at least 10.5 volts. If the charge is less than 10 volts, something is wrong. You should bring it to the shop for testing and possible replacement. However, for batteries in parallel wiring configurations, you can still use the other batteries by wiring around the bad one. You will have less available current, but this can get you by until you replace the old battery.

Hot Cables

Do your battery cables seem to be hotter than normal? Two things may cause this:

  • Increased load ? This might be a result of upgrades or something else draining the electrical system. For example, a bad starter motor will draw far more amps of current than a good one.

  • Undersized cables – If you have added on to your system, your current cables may need to be upgraded also. Maybe you have increased your lighting capabilities or added some accessories. You might need to replace a 6 cable with 2 AWG marine battery cable.

All the Batteries are Low or Dead

If you check the batteries and all of them are discharged or low, you should check to see if the alternator is working. If you have access to jump starting equipment, start the engine. Now disconnect the battery or batteries, making sure they do not touch anything grounded or other cables. If the motor dies, the alternator is not working. You also can check the voltage coming from the alternator with the engine running. On a 12-volt system, you should have close to 14 volts. Remember, when you replace a battery, consider also replacing parts like 2 AWG marine battery cable and check all inline fuses.

When you need wiring for your vessel like number 2 AWG marine battery cable, you can turn to EWCS (Electric Wire and Cable Specialists) for top quality materials. We also carry building, welding and security alarm cable and you can find us on the Web today at for more details.