The Best Jet Ski Battery Charger – Voltage, Amps, and Tips You Need

The best jet ski battery charger will be a 12-volt smart charger that charges at a max of 2 amps.

You must not charge over 2 amps, and you need to use a smart battery charger. There are also other little details you need to do that we’ll discuss below.

A battery charger sometimes goes by the names trickle charger and battery maintainer too.

Important: Just like a boat, it’s good practice to vent your jet ski for a few minutes before working on it or starting it, especially if it’s been sitting, or you just put gas in it.

1. NOCO GENIUS2, 2-Amp Fully-Automatic Smart Charger

My top pick for the best jet ski battery charger is the NOCO GENIUS2 2-Amp Fully-Automatic Smart Charger. Here are the reasons why it’s my top pick.

Buy the NOCO GENIUS2, 2-Amp Fully-Automatic Smart Charger Here*.

  • 2 Amps – not too much and not too little of charging power, it’s just right.
  • Smart charger – It turns on and off as the battery needs it.
  • Has a built-in maintainer.
  • Can detect sulfation and help restore a battery.
  • One of the few smart battery chargers that will try to bring back a dead battery.
  • Small – It doesn’t take up much room.
  • Its alligator clips are easy to use on jet ski batteries.
  • Temperature compensation – Needed for hot days or cold days in storage.

Tip: These battery chargers are the same you find for car batteries. So yes, you can use a battery charger made for car batteries for your jet ski battery, so long as it’s 12-volt and meets the correct amps.

2. Battery Tender Plus 12V Battery Charger and Maintainer

My second place pick is the Battery Tender Plus 12V Battery Charger and Maintainer. Here is why I picked it.

Buy the Battery Tender Plus 12V Battery Charger and Maintainer Here*.

  • 1.25 amps – Just enough amps to charge a jet ski battery at a good speed.
  • Super simple to use – Plug it in, connect to the battery and select 12 volts and let it go.
  • Maintainer – Turns on and off as the battery needs it.
  • Small – Stores away nicely when not in use.

3. Solar Battery Charger

Consider getting a solar battery charger like this one here*.

A solar battery charger is the best option if you need to charge or maintain your jet ski battery without a power outlet.

This is what I use on my jet ski to help maintain the battery, and I go over the full details here.

How To Charge A Jet Ski Battery

We have a post here that goes over the steps to charge a jet ski battery.

But here is a short version…

  1. For best results, remove the battery from the jet ski.
  2. Connect the positive cable of the charger to the positive post of the battery.
  3. Connect the negative cable of the charger to the negative post of the battery.
  4. Plug the battery charger power cord into the correct wall outlet.
  5. Wait for the smart charger lights to go on and let you know it’s charging.

When charging is done, remove the negative cable of the charger first and the positive cable next.

Battery Charger Is Not Charging Jet Ski Battery?

If the battery charger status lights don’t come on when you connect it to the battery, then make sure you have it hooked up right.

The positive cable of the charger goes to the positive of the battery, and the negative of the charger goes to the negative of the battery.

If the lights do come on, but the charger says the battery is bad, you need to get a new battery. The battery is too sulfated to recover.

If the battery charger says the battery is charged, but when you start the jet ski, it doesn’t start, then you only had a surface charge. There could be other reasons why your jet ski is not starting as talked about here.

A surface charge is not a full charge, and you’ll need to get a new battery no matter what the charger says about the battery charged status. Only a load tester can determine if the battery is good to start a jet ski and not the LED light on the charger. If you don’t have a load tester, many auto part stores will load test a battery for you, and a lot do it for free.

How Do I Know My Jet Ski Battery Is Bad?

  • 0 to 11.9 volts is considered bad.
  • 12.4 volts is considered weak.
  • 12.7 to 13.2 volts is considered good.

What matters more than voltage is amps, and a load tester can only test this. Many auto parts stores will load test a battery for you.

The easiest way to tell if your jet ski battery is bad is by listening to the engine area when you start your jet ski.

A weak battery will struggle to turn over, especially in the water.

A super-weak battery will give you multiple clicking noises when you press the start button, as talked about here.

A completely dead battery may power on the gauges, but nothing happens after that.

The majority of starting issues you’ll run into with your jet ski will most often be a bad battery. So if your jet ski won’t start replacing the battery is often the first thing you should do, even if you think the battery is fine.

Can You Recharge A Jet Ski Battery and How Often?

Jet ski batteries are rechargeable, but they will die and won’t recharge if you don’t use your jet ski for 4+ months.

It’s best to recharge your jet ski battery every 3 months that you don’t ride.

So if you don’t ride your jet ski in August and September you should charge your battery at least once in October.

Tip: If you’re not riding for a few months you should take the battery out and use the smart chargers with a maintainer built-in to keep the battery good when in storage.

Does Your Jet Ski Need a Battery Switch?

No, your jet ski does not have a battery switch and does not need one either.

The reason why your jet ski battery dies is not that the jet ski is always pulling a little power, but instead, it’s because the lead-acid battery goes flat if it’s not being used regularly.

If you ride your jet ski all the time, the battery stays active and lasts for a long time because it’s being used. However, when you leave it to sit for too long, it goes flat, and adding a battery switch doesn’t fix this.

Instead of a battery switch, consider getting a solar charger. When you’re not riding, hook up the solar charger, and it will keep the battery active and lasting for longer. See how I have my solar charger set up on my jet ski.

What Amp To Charge Jet Ski Battery?

You want to charge your jet ski battery at a max of 2 amps. Lower amps like 0.75 to 2 amps are fine too.

Going over 2 amps charges the battery too fast for these small batteries, and you can end up cooking the battery, which is very bad.

When charging your jet ski battery, you need to have it ventilated as lead-acid batteries release a small amount of hydrogen and oxygen when charging. Leave the access panel, seat, or hood ajar when charging your jet ski battery or better yet, take it out of the jet ski. Also, keep the rain off your jet ski when you have an access panel, seat, or hood open, so you don’t flood your jet ski with rainwater.

How Long Does It Take To Charge A Jet Ski Battery?

It takes about 12 hours to charge an empty jet ski battery fully.

It can take longer or shorter depending on what the smart charger considers is best for your battery. This is why we suggest using smart chargers as they turn on and off as they’re needed.

You need to let your battery charge fully and slowly if you want the battery to last. It’s best to not rush these things.

When Should You Replace A Jet Ski Battery?

The most I’ve gone without replacing a jet ski battery is 5 years, but that is because I kept it on the solar charger when I was not using it.

Ideally, it would be best if you replaced your jet ski battery every 3 years.

If you’re replacing your jet ski battery every year, then it means you’re not riding it enough or charging it enough during the off-season. Lead-acid batteries go bad when they’re not used for months.

You can sometimes recover a dead battery that’s been sitting for a long time by charging it, but a good bit of them don’t recover.

Why Does My Jet Ski Battery Keep Dying?

We have a guide that explains why your jet ski battery keeps dying here.

Can You Jump Start A Jet Ski Instead Of Charging It?

No, do NOT jump-start a jet ski battery, especially from your car or truck. I explain why this is bad in this post.

What Battery Do I Need For My Jet Ski?

You need a 12-volt battery that ranges in sizes from 16, 20, to 30.

What type of jet ski battery you need and what is the best one to get can be found in this guide here.

Do You Need To Add Water To A Jet Ski Battery?

Adding water to jet ski batteries is not very common these days.

Most manufacturers are moving to sealed jet ski batteries, which makes adding water a thing of the past.

Even if you have a non-sealed battery, I would not add water to it and instead, get a new battery. The trouble you would have to go through to get the distilled water, get a hydrometer, and mess with dangerous sulphuric acid is not worth it if you ask me.

Will Riding My Jet Ski Charge It’s Battery?

No, riding your jet ski will not fully charge your jet ski battery. It may give it a surface charge but nothing lasting.

Jet skis use a stator and not an alternator like your car.

A stator only maintains a charge and does not fully charge as an alternator would.

8 thoughts on “The Best Jet Ski Battery Charger – Voltage, Amps, and Tips You Need”

  1. Great advice on battery and charger. I am looking at purchasing our first jetski, Seadoo gti 130. This website has been invaluable to supply the information I need. Thanks very much

  2. Hi. Picked up the 2 amps NOCO charger and noticed the battery says charge at 1.8 amps. Will the extra charge amperage cause any issues? The same store also had a 1 amp NOCO available. Thanks.

    • It’s fine. I’ve never seen a 12-volt lead acid battery be that specific about charging amps (except maybe for computer power supplies, but not automotive), they usually round up to 2 amps. The biggest thing is that you don’t want to go over 2 amps, so avoid the 2.5, 3, 4, etc. amp chargers. Also, make sure it’s a smart charger, the ones that turn on and off as needed.

  3. Hey Steve
    I’ve just ordered a new GTX230 and will be keeping it on a Jetski Pod at a marina with a cover on it between rides, so no ability to have a smart charger hooked up.
    A little confused by your battery charging advice in that; on the one hand you say the battery needs to be on a charger if you’re not riding the ski for more than 3 months (winter). So I’m guessing it will be fine if I’m riding the ski at least once a month year round, but then you go on to say that riding the ski won’t change it up because it runs on a stator & not an alternator?
    So does this mean whether you ride it or not, it will still need to be charged up every three months?
    Maybe I’ve misunderstood you, can you please clarify.
    PS Yeah, we can ride year round in Oz no snow here. Our winters are just less hot than our summers
    Cheers Steve

    • It’s more about keeping the battery active than charging it. When you ride your jet ski it’s keeping the battery active with the stator and so does putting it on a battery charger. A stator will charge a battery but it’s more of a side effect of maintaining the charge. If you’re not keeping the battery active the internal plates sulfate and cause it to die, this takes months to happen. Charging a dead lead acid battery will sometimes loosen the sulfation and allow the battery to charge again but if you ride it more or keep it on a smart charger the plates won’t sulfate. If the sulfation is too much the battery won’t recover when using a battery charger.

      This is why I like the solar battery chargers as they supply just enough power to keep the battery active, they don’t even need to be in direct sunlight.

      So if you’re riding your jet ski often, once a month is fine, you don’t need to charge the battery as you’re keeping it active. But if you go the whole winter without running the jet ski or keeping the battery on charge you run the risk of the battery being dead because it sulfated too much and the battery charger might not be able to “smack it back to life”.


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