Why Does my Jet Ski Battery Keep Dying?

Unfortunately, it is very common for jet ski batteries to die. In this article, I will explain the main reasons why jet ski batteries die, and also offer some ways to prevent it in the future.

Why does my jet ski battery keep dying?

The main reasons a jet ski battery dies are improper storage, infrequent use, old battery, overcharging, or other electrical problems.

Improper storage

The main reason why your jet ski battery keeps dying is because you do not store the jet ski and battery properly. The biggest mistake I see people make is that they leave the battery in the jet ski. This will almost certainly drain your battery so that it is dead the next time you try to use it.

Also, leaving your battery inside the jet ski can cause it to sulfate. This occurs when substances start to build up on top of the battery which restricts energy from flowing in and out of it.

To prevent this from happening, it is important to remove your battery when you store it during the winter. You should leave your battery on a smart charger.

It only charges your battery when it is low, and also doesn’t overcharge it, which helps preserve the battery’s life. It is important that you put the battery and charger in a place that is dry and away from moisture.

You can learn more about storing your jet ski in my guide on how to winterize a jet ski.

Infrequent use

Another reason your jet ski battery keeps dying is because you don’t use it frequently. A battery is charged by something called a stator, and it only charges the jet ski while the ignition is on.

If you go months at a time without using your jet ski, your battery will not get enough charge and will eventually die.

If you plan on going more than a month or two without using your jet ski, I suggest you look into getting a solar charger. It attaches to your jet ski battery and allows your battery to stay charged while you aren’t using your jet ski.


Another mistake people make is that they overcharge their batteries. When a battery is fully charged too frequently, it will diminish the batteries capacity to hold electricity.

Overtime, your battery will be able to hold less and less of a charge. For this reason, it is important that you don’t charge your battery to full charge. An easy way to avoid this is by using a smart charger. It doesn’t fill the battery all the way up, and only provides enough energy to keep the battery alive.

You should also make sure to buy your charger from a reputable brand. Some knock off chargers are too powerful and can charge your battery too quickly, which will cause it to deteriorate over time. Knock off chargers also present a fire hazard.

You can check out some good charger brands in my guide on the best jet ski battery chargers

Old battery

A lot of people don’t know that you need to regularly replace your jet ski battery. I recommend getting a new battery every 4 to 5 years.

Overtime, batteries lose their charge capacity, which is why it is important to replace them. Old batteries can also malfunction and cause damage to other components of your jet ski’s engine.

There is also a chance that you have a low quality battery. You can check out some good brands in my article on the best jet ski batteries.  

Other mechanical problems

Lastly, there is a chance that your dying battery has nothing to do with the battery at all. Some common problems that will cause your battery to die include stator, rectifier, and regulator malfunctions. Unfortunately, if this is causing the issue, you will probably need to take your jet ski to a mechanic.

There is also a chance that your jet ski battery isn’t plugged in correctly. You should lift up the seat of your jet ski and inspect the engine area. Make sure all wires are plugged in and that there is no corrosion on the wires or engine parts. There is also a chance that your jet ski has just reached the end of it’s life. Keep in mind, it is not uncommon for jet skis to only last for 300 hours

If there is a lot of water in the engine area, you should check out my article on how to fix a flooded jet ski.


I hope this article helped explain the main reasons why your jet ski battery keeps dying. Most of the time it is due to improper storage and infrequent use. However, there is also the chance that your battery is fried and you will need to replace it.

Luckily, jet ski batteries are not too expensive and you can find a lot of cheap options on amazon. However, as I mentioned above, make sure you buy one from a reputable brand with positive reviews.
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