Have you ever experienced unexpected boat battery drain outs? It’s a common problem where boating enthusiasts often find themselves short on power due to unknown reasons. In most cases, the problem stems from short circuits in the boat.
Having a short circuit can be hazardous to your boat and the battery. In some extreme cases, it can potentially blow away your vessel before giving you a chance to act and resolve the problem.
Therefore, finding and rectifying a short circuit in your boat is quite critical for a comfortable boating experience.
In this post, we will explore the short circuits in boats. I will share some techniques to identify the shorts. Moreover, there are some tips for you to avoid such problems from occurring in the future.
What’s a Short?
The two terminals of a battery, also known as the hot and ground sides, come in direct contact. This is when a short circuit occurs. Most of the time, it happens through the boat’s body because that’s connected to the ground. However, there can be other reasons too.
Types of Short
Generally, there are two types of shorts. Here is a quick look:
This short occurs when a part of the circuit creates a direct path between the ground and power. It can happen in loads like lights, pumps, etc. Usually, a short circuit may take much longer to trace, but it has a more straightforward solution than ground shorts.
When a ground short happens, the current bypass through direct contact. Usually, it leaks through the rudders, drives, shafts, and hull fittings.
Therefore, the battery loads won’t get sufficient power. Hence, bypassing the current drains the battery. If you’re not aware of shorting problems, it’s easy to diagnose the issue as a battery problem and disregard the drainage’s actual cause.
Finding the Short
There are a couple of techniques that often work best. For that, first, grab a multimeter. This means that a multimeter should be on your list of boat accessories if it’s not there already.
Quick Tip for a Multimeter
Before we start finding the short, learn how a multimeter indicates a short circuit. Usually, a multimeter will have a buzzer symbol. So, locate the sign and follow the next steps:
- Set the multimeter dial to the buzzer symbol
- Touch the metallic end of both the probes to your suspected short circuit area.
- If the buzzer gives a beep, it means that the path is short, signaling a short circuit.
Detecting a Ground Short
One of the leading causes of ground shorts is poor or lack of insulation between the circuits and your boat’s body. Especially if you have a large boat, there are higher chances of ground short.
It usually occurs through the bilge water that creates electrical contact between the body and the power line. The other reason could be a broken ground wire, but that is quite rare.
To detect the ground short, first, switch off the loads on your boat. If you have solar panels, disconnect them too. Next, follow the given instructions:
- Keep your battery switch ON and remove the cable connected to the positive terminal of your battery.
- Set your voltmeter to DC volts and measure the voltage between the disconnected cable and your battery’s positive terminal.
- If you get the rated battery voltages (12Volts in most cases), it means there is a short.
- Turn off the battery switch. At this point, only the bilge pumps remain connected to the battery.
- Check for voltage again.
If you’re getting voltages, it means that the issue is on the battery side.
- Rewire the suspected connections and check for short again.
- If there is no voltage, the issue resides at the boat side.
In such a case, you will have to isolate the boat side to prevent further shorts. Do the following:
- Turn the battery switch ON. The meter should give a voltage reading at this point.
- With the meter still connected, sequentially remove the breakers, and check which breaker induces no voltage reading.
There can be more than one breaker in the panels that are causing the leak. In such cases, remove the breaker connections. Turn them off and check for continuity. If it still shows connectivity, that’s the real culprit.
Detecting a Short Circuit
Finding a short in a circuit is much simpler than a ground short. Although it’s visually impossible to figure out, your multimeter set on the buzzer should efficiently do the job. Follow these steps:
- Turn OFF the battery switch
- Remove a suspected circuit from the panel
- Turn all the switches in that circuit to the ON position
- Place the multimeter probes on the positive and negative terminals of the circuit
If the multimeter beeps, it’s a signal for a short circuit. Otherwise, a high resistance reading means that the course is just fine.
- If your circuit passes the test, move on to the next circuit until you find the fault.
In case none of your circuits is shorted, it means that a ground short has occurred.
Quick Tips for Finding Shorts
At times, you can figure out a short without any equipment. For instance, if you see any wires dipped into the bilge water, it’s a strong possibility of a body short. If there are any uncovered terminals or circuits, start testing the shorts with them. Hence you will be able to catch the culprit quicker.
Areas in constant water contact, like the bilge pumps, live well pumps and the washdown, are often the cause of body shorts.
How You Can Avoid Short on a Boat
To prevent shorts, ensure that your boat terminals and contact points are well insulated. Also, make sure that the electrical contacts haven’t worn out. It’s one of the essentials during boat maintenance.
Secondly, check if there are any loose wires or cables, and reinforce them. Such simple measures can help prevent huge losses.
Regardless of what boat you might have, if it’s electrically powered, there can be shorts. It’s also essential to take professional help if you’re unable to detect the problem.
Start by making a habit of checking for shorts before a new boating adventure. Small things matter when you’re out in the waters, so never take a chance.