6 Ways to Tell When Marine Battery Cables Need Replacing

Battery cables on boats are very durable but they do not last forever. Each time you start the motor it heats the cables and then they cool off afterwards. Constant heating and cooling can eventually cause the insulation to break down and, over time, the battery cables may have more resistance inside. Whether you have #8 AWG marine battery cable or 0000 cable, it’s important to check them periodically. Here are six signs of potential trouble ahead.

1. Engine Starting Problems

Does the engine have to turn over more times than it used to to start up? Perhaps you have tuned up the motor and are still having problems getting started sometimes. If you can’t otherwise find the source of the problem, you might want to check your marine battery cables.

2. Hot Cables

Sometimes one battery cable may get much hotter than the other. This usually occurs after running the motor for some time. If you are having problems getting started, try feeling both of the cables after you have brought the boat in. If one cable is hot, it may be time to change them.

3. Strange Odors

Have you noticed any strange or unusual odors around the boat battery lately? Maybe it smells like burned rubber or plastic. This could be a sign your cables are getting overheated. When cables get too hot it can cause the insulation to begin to burn or melt, which may emit strong odors.

4. Stiff Cables

As cables begin to wear they will stiffen. This is often caused when the insulation begins to break down. Grab the cables and see if they are soft and flexible. For example, if you grab a #8 AWG marine battery cable it should sag or bend. If it keeps its shape, then it may have significant wear and you should consider replacement.

5. Increased Voltage

As marine battery cables wear they may conduct more voltage than normal. For example, once a 12-volt battery is fully charged it may hold as much as 14.4 volts. However, if you notice voltage in excess of 14.5 volts, it probably isn’t a good sign for the cables.

6. Greater Resistance

Marine battery cables need a certain amount of resistance to operate properly. Heat, vibration, and wear will cause more resistance. When resistance increases so does friction and friction causes heat. This can make your cables excessively hot and lead to all kinds of problems. Check your cables with an ohmmeter and if there is more than one ohm of resistance, you should consider replacement.

When you replace cables, always use premium, copper tinned cables. This will deliver the best performance and it won’t cost you much than a discount cable. The best suppliers provide top quality #8 AWG marine battery cable and many other popular sizes.