Boat Battery Died? Here's What You Need To Do

A dead boat battery can be a nightmare, but there are several ways to deal with it. First, you need to identify the cause, which could be anything from a charging issue to a parasitic draw. If you're able to prepare ahead of time, it's a good idea to buy a set of jumper cables and keep them on your boat. If you're already stranded, you can try jump-starting your boat with a spare battery, with a battery from another boat or car, or with a jump starter. Alternatively, you can take the battery out of the boat, charge it, and then put it back in. If none of these methods work, there may be a problem with your battery or your outboard.

Check the engine cutoff switch

If your boat won't start, it is recommended that you first check the engine cutoff switch. Engine cutoff switches can become disconnected when there is a lot of activity on a boat, especially if young children are on board. They tend to sit in the captain's seat and play with things. Therefore, it is important to ensure that the engine cutoff switch is properly connected before doing anything else.

If you are stranded with a dead battery, there are a few other simple steps you can take to try to get your boat up and running again. Firstly, check the connections. Ensure that all connections and the ground wire have a proper and tight connection and that there is no corrosion buildup on the battery. Touch the wires to make sure they aren't hot. If the wires are hot, there is likely a bigger problem somewhere else on the boat, which could lead to other issues or even a fire. If this is the case, do not jump-start the engine.

Secondly, if possible, keep a small meter or battery tester with you on the boat. This can help you determine if your battery is actually dead, has low voltage, or if something else is wrong. A battery is fully charged at a minimum of 12.8 volts with no load. However, due to onboard computers and other technology, it is normal for the full-charge voltage to be a bit lower. When a battery reaches no higher than 12.4 volts at full charge, it's time to replace it.

Finally, some boats are equipped with more than one battery and a battery switch. If one battery does not start, try switching to the backup battery or the "BOTH, ALL, or 1&2" position to get the motor running again so you can make it back to shore.

Check the connections

If your boat battery dies, you should check the connections. Ensure that all connections and the ground wire have a proper and tight connection. Check for any corrosion buildup on the battery. Touch the wires to make sure they aren't hot. If the wires are hot, there is likely a bigger problem that could lead to other issues or even a fire. Do not jump-start the engine. Instead, get a tow.

If you have an on-board generator, you could fire it up to charge the dead battery and then start the engine. It may also be possible to use jumper cables to connect the engine to the generator battery, assuming the generator itself is healthy.

Jumper cables are often impractical on boats because they usually aren't long enough to reach another boat's battery. However, if you have a spare battery, you can jump-start your boat with it. Connect both the battery terminals properly. Connect the negative (black) jumper wire to the dead battery's negative terminal and the good battery's negative terminal. Similarly, connect the positive (red) jumper wire to the dead battery's positive terminal and the good battery's positive terminal. If the spare battery is in good condition, it will immediately start the battery, and you can remove the jumper wires right away.

You can also jump-start your boat with a battery from another boat or car. Connect both the battery terminals properly. Connect the negative (black) jumper wire to the dead battery's negative terminal and the good battery's negative terminal on the battery of the other boat or car. Similarly, connect the positive (red) jumper wires. Start the other boat or car, but do not start your boat. After 15 minutes, remove the jumper cables and start your boat. It will start, and you can wait another 15 minutes to fully charge your battery with the boat alternator's help.

Another option is to take the battery out of the boat and use it after fully charging it. Disconnect all the wires and remove the battery from your boat. Locate the battery and remove all the wires that are connected to it. After removing the battery from the boat, charge it fully. Then, place the battery back in the boat, connect all the connections, and start your boat. It will start unless the battery is bad or needs replacement.

Finally, you can use a jump starter to start your boat. Jumpstarters are portable battery devices that allow for jump-starting boats and other vehicles. Connect the negative (black) jumper wire from the jump starter to the dead battery's negative terminal. Similarly, connect the positive (red) jumper wire from the jump starter to the dead battery's positive terminal. It will start the boat, and you can remove the jump starter cables right away if the boat starts.

Check the voltage

If your boat battery is acting up, it's important to check the voltage to see if it's dead or dying. This can be done with a small meter or battery tester, which will help you determine if your battery is dead, has low voltage, or if something else is wrong.

A fully charged battery should have a minimum of 12.8 volts with no load. However, due to onboard computers and other technology, a full-charge voltage can be a bit lower. When a battery reaches no higher than 12.4 volts at full charge, it's time to replace it.

If you're experiencing a sluggish engine or your boat isn't starting at all, it's likely that your battery is dead. In this case, you have a few options to try and get your boat going again. You could try jump-starting your boat with a spare battery, or by connecting to another boat or car battery. If these methods don't work, you may need to take the battery out of the boat and charge it externally before placing it back in.

It's important to note that you shouldn't try to jump-start a boat if its battery is damaged. Additionally, attempting to jump-start a marine battery with a car battery could damage the boat battery and the boat itself. Instead, you can use a jump starter, which is a portable battery device specifically designed for jump-starting boats and other vehicles.

By regularly checking your boat battery's voltage and keeping it properly charged, you can help ensure that you won't be stranded with a dead battery on your next boating trip.

Switch to a backup battery

If your boat battery dies, one of the solutions is to switch to a backup battery. This is a good solution if your boat has more than one battery and a battery switch. If one battery does not start, try switching to the backup battery, or the "BOTH, ALL, or 1&2" position to get the motor running again so you can make it back to shore.

If you are on the water and your boat battery dies, there might be an issue with the charging system or the electronics on the boat might have drained the battery. If the engine's charging system is not operating properly, the engine will use electricity from the battery to operate the ignition system. Once the battery is drained, the engine will shut off.

To prevent your boat battery from dying, you can take a few precautions. Firstly, check that the engine cutoff switch (ECOS) is properly connected, especially if there are children on board who might have tampered with it. Secondly, ensure that all connections and the ground wire have a proper and tight connection, and there is no corrosion buildup on the battery. Thirdly, touch the wires to make sure they are not hot, as this could indicate a bigger problem. Finally, keep a small meter or battery tester with you on the boat to determine if your battery is dead, has low voltage, or if something else is wrong. A fully charged battery should have a minimum of 12.8 volts with no load, but due to onboard computers and other technology, a full-charge voltage may be slightly lower. When a battery reaches no higher than 12.4 volts at full charge, it's time to replace it.

If you don't have a backup battery, there are a few other ways to deal with a dead boat battery. One way is to jump-start the boat with a spare battery, a battery from another boat or car, or a jump starter. Another way is to take the battery out of the boat, fully charge it, and then place it back in the boat and reconnect all the connections.

Call for a tow

If your boat battery dies, you may need to call for a tow. Here are some detailed instructions and considerations for when to call for a tow:

First, it is important to note that if you are stranded with a dead battery, you are not alone. Dead batteries are a common issue for boaters, and Sea Tow Captains frequently receive calls for assistance with low voltage or dead batteries. In fact, according to Captain Christian Orfanello of Sea Tow New Orleans, they typically jumpstart over 50 boats during the summer months alone. So, if you find yourself in this situation, don't panic and know that help is available.

Before calling for a tow, there are a few simple steps you can take to try to get your boat running again. Captain Christian recommends first checking the engine cutoff switch (ECOS), as it is not uncommon for this to become disconnected, especially if there are young children on board who may have been playing with things. If the ECOS is properly connected, the next step is to check the connections and ensure that all connections and the ground wire have a proper and tight connection, with no corrosion buildup on the battery. It is important to touch the wires to make sure they aren't hot, as hot wires could indicate a bigger problem that could lead to other issues or even a fire. If the wires are hot, do not attempt to jump-start the battery and call for a tow instead.

If the connections look good and the wires are not hot, the next step is to check the voltage. It is helpful to keep a small meter or battery tester on your boat to determine if your battery is actually dead, has low voltage, or if something else is wrong. A fully charged battery should have a minimum of 12.8 volts with no load, but due to onboard computers and other technology, it is normal for the full-charge voltage to be a bit lower. When a battery reaches no higher than 12.4 volts at full charge, it is time to replace it.

If you have more than one battery on your boat and a battery switch, you can try switching to the backup battery or the "BOTH, ALL, or 1&2" position to get the motor running again so you can make it back to shore. This may be enough to get you going without needing to call for a tow.

However, if none of the above steps work and you are still stranded with a dead battery, it is time to call for a tow. Sea Tow members, for example, receive free jump starts as part of their covered services. If you are not a member of a similar service, you may need to contact a local towing company or marine assistance provider for help. Keep in mind that attempting to jump-start a boat with a car battery could damage the boat battery and the boat itself, so it is generally not recommended.

In summary, while a dead boat battery can be frustrating, there are steps you can take to try to get your boat running again. But if all else fails, don't hesitate to call for a tow to get the assistance you need.

Frequently asked questions