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The Best Jet Ski Battery + What Size You Need

Ah, the thrill of the open water on your personal watercraft (PWC) — until the dreaded moment when your battery decides it’s time to call it quits.

For many PWC owners, dealing with battery issues is an all-too-familiar headache that can quickly put a damper on their aquatic adventures. From unexpected dead batteries to the challenges of maintenance and replacement, PWC batteries can indeed be a pain.

In this post, we’ll dive into the world of PWC batteries, exploring the common frustrations they pose, the reasons behind their unpredictability, and offering our suggestion on which ones to buy.

The Best Battery For PWCs

The best overall batteries you can get are the ETX16L, ETX20L, or ETX30L, depending on the size needed!

The Correct Yamaha Battery To Buy

If you have a Yamaha waverunner, you need a 16L battery (Amazon Link Ad).

ETX16L is what I recommend, but you can often find these part numbers that’ll work too… ET16L, B2317RP, UT16L-B, UB16L-B

The Correct Kawasaki Battery To Buy

If you have a Kawasaki, you need a 20L battery (Amazon Link Ad).

ETX20L is what I recommend, but these other part numbers will work too… MBTX20U, UTX20HL, UTX20HL-BS, B2015, YTX20HL, MBTX20UHD, DURAGM-20L

The Correct Sea-Doo Battery To Buy

  • Before 2002, needs a 16L.
  • 2002 to 2007 2-Stroke needs a 16L.
  • 2002 to 2007 4-Stroke needs a 30L.
  • 2008 to 2015 needs a 30L.
  • 2014 and up Spark needs 20L.
  • 2016 and up Sea-Doo needs a 20L.

Get the batteries here:

Note: The ETX30L is sealed so it is shorter than the unsealed one, so a spacer is needed and should come with it.

  • ETX16L is the one I recommend, but these part numbers will work… ET16L, B2317RP, UT16L-B, UB16L-B
  • ETX20L is the one I recommend, but these part numbers will work… MBTX20U, UTX20HL, UTX20HL-BS, B2015, YTX20HL, MBTX20UHD, DURAGM-20L
  • ETX30L is the one I recommend, but these part numbers will work…UIX30L, B3121, MBTX30U, YIX30L

How To Tell If You Have a 2-Stoke or a 4-Stroke

How can you tell if you have a 2-stroke or a 4-stroke? Do you have the dipstick on the top of the engine? It’s either a yellow or red dipstick cap located at the top of the engine, as shown below.

Point to the dip stick on a PWC

If you have a dipstick, you have a 4-Stroke engine. If you have a Sea-Doo made on or after 2008, then it’s a 4-Stroke.

Check out our guide to help you further know if you have a 2-stroke or a 4-stroke.

Locating The PWCs Age Using The VIN

To find the year the machine was manufactured is easy on boats.

On the back of the craft, you will have the VIN. It’s most often on the upper side of the rub rail, but on older ones it will be under.

The VIN last two digits tell you the year it was manufactured.

VIN placard on the rear
VIN example with white background

Using the images above, we can see the first image ends in D212, so it’s a 2012 model. E414 would be a 2014 model, and a J220 would be a 2020 model.

Keeping It Charged Is How You Get The Most Life Out Of It

If you’re not keeping the battery on charge when you’re not using it over a month, then it will only last one riding season!

Keeping them on a charger is super easy to do with solar panel chargers. They’re quite affordable and far easier to deal with than wall chargers.

When I’m not riding my Sea-Doo, I use the quick connect and hook up the solar charger. Doing this, I have gotten over 5 years out of my sealed battery. I got my Spark in 2014 and did not change the battery until summer 2020.

A solar charger won’t work? If a solar charger won’t work, I recommend getting a wall charger. You’ll want a smart battery charger like this here (Amazon Link Ad), so it won’t overcharge the battery. The battery charger needs to be 12 volts and less than 2 amps.

Avoid Boat Battery Switches

DO NOT install a battery switch on your PWC!!!

I’ve had a few people do this, and it never works out.

The problem is not that the system consumes a little bit of power when you’re not using it, but the fact that lead-acid batteries sulfate and die when they’re not used.

This is why I love solar chargers. The solar charger does charge the battery (very slowly) but the thing it does better is maintaining the battery. It maintains the battery by keeping it active, which keeps it from sulfating and dying. The solar charger is basically “tickling” the battery instead of letting it sit and do nothing, which kills it.

My Engine Clicks?

If the engine gives one click, then it’s a bad starter relay.

If it gives multiple clicks, then it’s a bad battery.

To fix this, I have a guide here.

Engine Turns Over On Land, but Not Water?

If the engine turns over and fires up on land but not on water, then that is a sign the battery is weak.

PWCs use a direct drive system, so when you’re turning the engine over you’re also spinning the impeller, and that is much harder to do while in the water!

How To Change

The most common tools you’ll need to change a battery are…

  • 10 mm wrench and socket
  • 13 mm socket
  • Phillips head screwdriver
  • 12-in extension

Here are videos showing you how to change batteries in PWCs.

Sea-Doo Battery Replacement Video

Yamaha Battery Replacement Video

Kawasaki Battery Replacement Video

Author

Steven

I started working at a power sports dealership in 2007, I worked in parts, service counter, and as a technician before moving to sales in 2013. I created StevenInSales.com in 2014 to answer common watercraft questions I would get from people. Now managing the site full-time, I continue to provide advice and web tools for my readers about watercraft. I've owned several watercraft, with a Sea-Doo Spark as my current main PWC.

Comments

  1. Hello. Great information. I’m looking at the Weize, Deka ETX, and Yuasa, all YTX 20l-BS replacement for my GTX 2021/230 battery. Any preference, or recommendations. Thanks for all the information you provide.

    Reply
  2. Is it better to run 2 batteries or one 32amp battery? I have sound, fish finder and marine radio on my seadoo 2022 170 I was just about to run two batteries when i saw a video in Australia who runs a 32 amp single

    Thoughts??

    Reply
    • The most ideal would be two batteries with a battery switch. When one battery dies, you switch to the good battery. If there is no battery switch, then basically you already have two batteries acting as one, but having one big battery will be slightly better due to weight, cranking and durably plus ease of use.

      Reply
  3. I have a 09 Yamaha vx 110 is a small lawn mower battery that has 350 cca to much I understand it is slightly bigger in size but I made a tray for it to fit will it harm the electronics or affect the charging system the old battery had 260 cca

    Reply
  4. Hi and thanks for all the great info you provide. I have 2006 Honda Aquatrax F 12. Just turned 100 hrs. I have been trolling w it and 2 times the battery has not started after trolling 2-3 hrs. Luckily I carry small rechargeable jumper that fires it right up while I’m out there. Is it normal the battery will drain at idle in 2-4 hrs? after going straight in at full 3/4 throttle after dead battery it fires Rt up once back at dock. Battery reads 14.7 at idle on tester. Going to replace the battery. So main questions are: 1)do Honda’s drain battery at idle
    2) what battery do you recommend for Aquatrax?
    3) what do you think of Yuasa batteries for skis?
    Thank you

    Reply
    • It should not drain while running at idle. Your stator or rectifier could be going bad. I recommend a sealed lead acid battery like the ETX20L.

      Reply
  5. Hi Steven,
    I have a Seadoo Fishpro 2019 that has a fishfinder, sound system as well.
    Would you get a MBTX20U or MBTX30U ?
    Thank you!

    Reply
  6. Steven – I have the Yamaha VX. OEM battery is YB16CL-B but what do you think of AGM batteries vs. Lead (especially in colder weather)? If AGM is ok, which one do you recommend?

    Reply
    • AGM or sealed lead acid batteries are always better but they still need to be put on a smart charger if you don’t ride for more than a few months.

      Reply
  7. Hi steve, i have a 2004 seadoo GTX supercharged and have replaced the lead acid battery with a:
    CYL10073 X2Power 30L-BS 12.8V 560CA Lithium Powersport Battery (because i read those can withstand all winter time without a charge and still start)
    I put it in and it starts great, but now i read that its not good for any ski/motorcycle because some over or undercharge the battery. Should it be ok? What do you think?

    Reply
    • I would stick with the sealed lead-acid batteries. Lithium batteries need a special charger and an onboard charge controller for each cell to keep it in tip-top shape. A lead-acid battery is simpler and if kept on a charge during the winter will last a few years at least. I keep the solar charger on my battery when I’m not using it and my battery lasted 5 years.

      Reply
  8. The link you have for the 20xl Sea Doo battery shows it not in stock and no expected return date. No one locally has batteries nor does Lowes. Can you give me a different recommended battery for my 2017 Sea Doo?

    Reply
  9. I have an 01 Polaris Virage 1200. It has the 16L battery but I have had issues when the power dropped while cranking and wouldn’t start. The charging system is ok but since I’m
    Changing the battery anyway would it be better to go with the 18L if I can make it fit.

    Reply
    • I would use the battery size that is made for the watercraft. Either the battery you have now is bad or something else is keeping from cranking. Make sure the connection on the cables are clean, you need shiny copper showing, and you don’t have anything blocking the pump. A jet ski that old might have a worn out starter motor and make it sound like the battery is weak.

      Reply
  10. Hi, this seems to be a great forum to discuss Batteies for PWC. Thank you. I have ‘inherited’ a 1998 Seadoo GTX 2 Stroke. Original Battery is a 16L i think. When I look on walMart cross reference, it recommends the es-tx30L. You also recommend the 30L. I noted that the battery compartment is my concern. will the etx30L fit the narrower size compartment? I dont see dimensions on the battery link. SIdeNote: i’m a 40 year boater with a 32 yr old evinrude. YES- solar trickle charger is the easiest Battery maintainer. My batts last 5-7 years! I also remove the batt every winter, bring them inside and trickle charge 1/month for 3 days.

    Reply
  11. Hi Steven,

    I have a 2018 GTX 155 and was looking for replacement battery. Is the ETX20L by Deka the correct size?

    Thanks in advance!

    Reply
  12. I have a 2014 Yamaha FX Cruiser HO. Based on your comment about some 4 stroke Yamaha Waverunners use the 2 stroke battery I am not sure which one to purchase. Can you help me out please? Thanks!

    Reply
    • I’m not a fan of them. They cost more and don’t fit in the mounts that are made for lead-acid batteries that jet skis have. You’re better off getting the correct size lead-acid battery for your jet ski and when you’re not using it keep the battery on a charge with either a smart battery charger or a 5-watt solar charger.

      Reply
  13. Hello, I have 2002 gtx 4 tec seadoo. I just bought it and it came with a 230 cold cranking amp battery that is a lawn tractor battery. I’m going to by the proper battery tho I have a question. Is this battery way under to start this 4 tec engine. Thank you

    Reply
    • Yes, that is way under the CCA needed. The EXT30L has 400 and that is what you need. It’s also important to get the proper size battery so that it fits in the battery cage properly. Too small of a battery and it bounces around and can yank and destroy the battery cables and other components in the engine bay.

      Reply
  14. Thanks for the thread, its very informative. I have a Yamaha 2010 VX deluxe that I use to troll fish in Hawaii, will the 30L fit in my jet sk?, i since I read your suggestion about not using the 16L. Please advise! Thanks!

    Reply
  15. Hi Steven, I bought a new battery for a 1989 Yamaha wave runner 500. That old ski died right afterwards, and my husband bought us a 3 seat Seadoo GTR that is a
    2014 year model. Can we use the Yamaha battery for the Seadoo? Thanks

    Reply
    • That 2-stroke battery won’t work in that model, you’ll need to get the correct ETX30L battery for that Sea-Doo.

      Reply
  16. Hey Steven,

    2 questions:

    1. How much cranking amperage should a 97 Sea Doo have to start? My battery has 325.

    2. Should the cranking amperage charge up with the trickle charger? My colts charged, but my cranking amps stayed about half way.

    Thanks

    Reply
    • 325 CCA is fine for a 2 stroke. It sounds to me that your battery has gone bad. It’s the amps that start the engine, not the voltage. Take it to your local auto parts store and ask them to load test it, load testing is how you confirm it has enough power to start an engine.

      Reply
  17. Great thread and video, very helpful. I have an 07 Seadoo Gtx 155, sitting in my Florida garage for a while and let the battery die. I removed the battery, charged it through the cycles (charging >80%full>full) using my battery tender junior which is also a smart charger, but when I connected the terminals the light went back to red indicating a charge. 24 hours later and it still isnt even at 80%. Can there be an internal issue causing it to not hold a charge? Hoping it’s the battery, bought the ski used about 2.5 years ago haven’t changed battery once. Usually keep it on a tender

    Reply
    • Sounds like the battery is worn out. You’ve been doing everything right with keeping a smart charger on it but the battery could be old and worn out if you never replaced it since you got it.

      Reply
  18. Hi Steve! Really useful comments on your website. I own a 2010 gtx 155. Always the same problem with the batteries. I think they are to small to crank a 1500 cc engine. Is it possible to put a bigger battery ( Lets say 50 amp) on the ski? I have this question about the stator, one time someone told me I could ruin the electric parts having a bigger more powerful battery. Is this correct? With a 50 amp battery the engine starts really good and its more reliable than ever.
    Thanks for your help.

    Reply
    • It’s best to stick to the ETX-30L size battery for your Sea-Doo. The battery should fill up the space that the cage you use to hold the battery in place for your Sea-Doo. Dry cell ETX-30L’s will need a bottom spacer because they’re shorter than the manufacturer battery but still fill up the cage. So it’s not possible to fit a bigger battery into your Sea-Doo. I’ve seen people use smaller batteries but they don’t have enough cracking apps to start the craft and this might be your issue. Make sure to use an ETX-30L in your Sea-Doo and not a 20L or 16L, there should be a number on the battery telling you the size of it whether it is a 30, 16, or 20.

      Reply
  19. Forgot to mention that it wasn’t as tall as my yuasa OEM so I had to place something on top to keep the straps tight. Was asking if I should have bought the 30 that you mention above – what do you think? This site is a great resource

    Reply
    • Yamaha uses a smaller battery then the size 30 I recommend above, the size 30 is for a select few Sea-Doo’s. They should have given you a spacer as some AGM batteries are smaller than the liquid ones you get from the factory.

      Reply
  20. Steve
    If you store your jet skis in a garage can you leave them in the jet ski and charge them? Should you still disconnect the terminals?
    Thanks, Scott

    Reply
  21. Hello, sorry another question. I see people say all the time, in the winter when not using ski to pull the battery out and charge it out of the ski. Is this true that the battery must be pulled out and not connected to the ski or is it okay to leave it in the ski and charge it in the ski still connected? Thanks!

    Reply
    • For the battery you want a size 30L, I like to use ETX30L which is the 4-stroke battery I mention in the post above. If you can take out the battery and keep it on charge during the winter. The biggest reason is so that you can store the battery in your garage or somewhere that is dry and warmer than where you keep your jet ski. If you keep your jet ski outside during the winter then get a solar battery charger that is under 5 watts and keep it charged that way, here is more info on that… https://www.steveninsales.com/need-solar-panel-jet-ski-battery/ I have a video here on how to take a battery out here… https://www.youtube.com/watch?v=TRk7FDFd1Hw

      Reply
  22. Hi Steven.
    I serviced my jest ski a year ago at the dealer and put it straight back into storage in my garage without using it after the service.I bought a new battery at the sametime aswell and left it sealed inda the box until today. I took jetski out today as im planning on using next weekend. . . And wanted to just start it up so to be sure its ready for next weekend. I placed the brand new battery in and tried to start it but it refuses to start.
    The gauges and modes showed up on the display screen and the warning light flashes but there is no warning description or code on the screen.

    Tried starting a good few time with no luck.
    Then eventually i tried to start it a last time and it still wouldnt start, but this time on the display screen it just shows the word “Start”. . .nothing else. . .and ot still wont start up either. Im baffled. . . Pleas help me.

    Reply
    • Sounds like a dead battery. It’s not good to leave a battery untouched for a year, it sulfates if it doesn’t get a charge. You can try charging it to see if it will come back but more then likely it will need to be replaced. If you plan on not using your jet ski for a month or two it’s best to keep the battery on a smart charger like we talk about in the post or if you keep it outside you can use a solar charger that is less then 5 watts. I currently use a 1.8-watt solar charger on my jet ski battery.

      Reply
    • Make sure the battery terminals very tightly screwed on. My 2stroke didn’t want to start even though display was working. It just not enough for current to flow in so jetski doesn’t even bother to make any starting sequence.

      Reply

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