Wavewalk 500 Battery Pack

By Captain Larry Jarboe

Florida Fishing Kayaks

After all the excitement of the S4 introduction, it is great to see people posting their W500 and W700 pics and modifications.

The narrow twin hulls make these the ideal stable paddle vessels. Also, the W500 and W700 kayaks are easy to convert to electric power with a simple bolt on transom mount available from Wavewalk..

However, most batteries are too wide for the W500 (and some extent, the W700) to fit down into the hulls.

My solution is to put two 35 AH 12 volt U1 deep cycle batteries end to end in a custom made tapered housing that slips down into the hull. These are batteries that are often used to power electric wheelchairs.

70 amps of 12 volt power will run a 30 lb. thrust Minnkota electric trolling motor at top speed setting (4-5 kts.) for a couple hours. Or, troll at half speed all day. Figure about $160 cost for the under 40 lb. battery pack. Compare with the weight and cost of any other 70 Amp Hour battery that will not fit into the streamlined hulls.

I made my battery box from a plastic planter tray and some PVC decking material. It fits perfectly and works wonderfully in my white W500 that was my original Wavewalk investment.

The only issue was the conducting material at the battery terminals. Stainless steel does not transfer electricity very well. It was hard to find anyone in the Upper Keys on a Sunday afternoon who had a pair of brass nuts.

Try asking for that commodity, anywhere.

Yes, I scored on the 5/16×18 nuts.

And, the 70 AH battery box combo carried me offshore for a post-hurricane exploration of the Atlantic Ocean.

But, that is another story…



  1. fish

    Thanks Larry,

    Indeed, with all the excitement of the new S4, we tend to forget the two other marvels 😀
    I like the planter tray a lot, of course, and the price tag is very reasonable. This setup looks like something that anyone would enjoy, including your clients.
    Typically, we tell people to use two small-size batteries, and place one at the bottom of each hull, in order to improve stability.
    And people should also be reminded to coat exposed wires or nuts with a thick layer of grease, in case some spray gets in…


  2. Bassman


    With the first battery pack tested, I plan to build a second one for the other side. This will give me lots of range and balance for the W500 snorkel sled tow rig. Also, this battery pack will work well for quick, low maintenance, short distance, catch some dinner runs with the S4.

    I coat my crimp on terminals with a compound called Liquid Lectric. It is a black plastic liquid that brushes on and dries to seal those connections from moisture. Also, I tap out the flat battery posts with a 5/16×18 thread tap to make my connections that much more secure.

    As much fun as the outboard motors are, paddling (kayak or canoe style) and electric cruising in all of the Wavewalk models are most joyful, as well.

    Is it possible to have too much fun?

    Larry J.

  3. fish

    Thanks Larry, this is useful info.

    “Is it possible to have too much fun?” sounds like a philosophical question 🙂
    I just got an email from a client in NC who went shrimping yesterday with two other family members, all three in their S4. They caught 12.5 lbs of shrimp in a 1.5 hour trip… (not a typo)
    That’s too much fun too, if you ask me!


  4. RoxCT

    Nice set-up with the batteries.

    Those are the same style batteries I used for my Electric powered
    W300, which is still going strong, an Older Gentlemen from Simsbury Ct. bought it from me.

    And I agree, put them on both sides for better balance.

    We can never have to much fun in the wave walk kayaks, everyday is a new adventure
    in a Wave Walk Kayak.

    Tight Lines and MoPaddle safe all.

  5. fish

    I can’t believe people still fish out of the W300… and with a motor! 😀

  6. Bassman

    Rox and Yoav,

    The placement of batteries at the bottom of the W-series hulls and the majority of propulsion weight (the electric motor) below the surface makes these vessels even more stable when converted to electric power.

    The electric trolling motor acts as a bulb keel and could be used as a powered rudder for Wavewalkers who wish to raise a sail.

    Admittedly, I have become somewhat spoiled by quickly planing across the surface in my S4 powered by a gas sipping outboard motor. But, silently slicing through the chop at maximum displacement speed with no fumes and minimum moving parts is a pretty good way to go, too.

    The saying, “Getting there is half the fun.” might not be totally accurate. I think the percentage may be considerably higher.

    Larry J.

  7. fish

    Next: An outboard gas engine that’s totally submerged, except the gas tank… 😮

  8. Bassman


    That submerged outboard gas engine remark really jogged my memory bank.

    Back in the late 1970’s, on our dive boat, we did some beta-testing on the Aquascooter which was a submerged snorkel scooter powered by a 2 cycle gas engine. It pulled in air through a snorkel tube that extended above the surface.

    If you released it under power the centrifugal prop force would make it circle back to you.

    With a daily rinse in the freshwater tub, it was pretty low maintenance and lots of fun.

    From a quick I-Net search, it looks like they are still in business, today.

    Larry J.

  9. fish


    I can imagine that being submerged, such motor does not require a water pump for cooling, since it looses enough heat to the water around it.
    No transmission either, since its propeller can be attached directly to a horizontal shaft, so the whole thing would be rather small, possibly the size of an electric motor.
    And no noise for the driver and passengers to hear…


  10. Bassman


    The rest of the story regarding the Aquascooter involves the inventor’s remarkable escape from a Soviet Bloc country…

    Yes, the benefits of submerging an outboard motor are there. But, the exhaust of the Aquascooter still bubbled up right beneath one’s own breathing apparatus. It was kind of noxious to be around.

    And, barracuda seemed to be especially attracted to the cavitation of that little encased prop. So, while you were downstream of the exhaust inhaling pollution laden air, there were creatures in the water considering inhaling you.

    And, that is the rest of the rest of the story!

    Larry J.

  11. fish


  12. Pyt Rotary

    Hi Folks,

    I am a big, big, big fan of the electric motor.
    Mostly because I like to fish by trolling, and the best trolling fine setup is on electric.
    If you want to hold well and smooth above you fishing hole the electric is the answer.

    If you want to get the best of electric in a Wavewalk go directly for 24 Volts motors from Minnkota of course.
    Because of following reasons:
    1) 2 batteries placed in each hull balances well the kayak, one battery will just drag too much one side.
    2) 24 Volts motors are more efficient than a 12V (high voltage more efficient than high amps)
    3) with 24V and 2 batteries you will have way more thrust and range
    4) use only AGM or gel U1 size batteries (Wheelchair type) around 22Lb weight each.
    5) buy a smart charger and keep the batteries all the time full charged. If you want to destroy your batteries (lead-acid) keep them discharged for more than few days.

    I did experiment with at least 8 electric motors in last 6-7 years. I do have now (settle down):
    A) one Minnkota 24V 70Lb thrust for the W500 I own for rivers small lakes
    B) one Minnkota 36V 101Lb thrust for S4 I own for big lakes when I do trolling.

    Buy the Minnkota motors that have Digital Maximizer only, these ones use the best the juice from batteries. 5 time longer time on water they say. Definitely a lot longer than the motors with no Digital maximize.

    I use the gas motor only when I take the S4 on long trips on great lakes.
    Once you master the electric you never look back.

    Have fun and be safe.

  13. fish

    Thanks Pyt,

    This is useful info!


  14. RoxCT

    Thanks Pyt,

    You know I love the silence for the electric motor.

    And I have seriously thought of the minn kota’s with the spot lock if I did
    go all electric again. That quick reverse, and hands free steering was the best. 🙂

    I just love the gas motors, because of less weight, no worry about how long I spend on the water.

    Larry, can you remove the saddle bracket and slide the batteries down back and put the saddle bracket
    back in?
    That would give you more space, I did that with my batteries, worked out great.

    Tight Lines and MoPaddle Safe all.

  15. fish

    Great idea Rox!


  16. Bassman


    Yes, I can remove and replace the saddle bracket. But, presently, I am waiting on 2 more U1 deep cycle batts to be delivered for the other side. This W500 has a saddle bracket at each end. So, a slight trim job, instead, will let the batts side through while keeping saddle corner integrity. I need daily ease of removal so I can use the battery packs in other applications.

    This W500 will have a 24 volt pack (4 U1 batts in a series/parallel config.) set up to pull (not push) up to six snorkelers through the water. Ironically, I have a 70 lb thrust 24 volt Minnkota motor that I used to use bowfishing from a 16′ aluminum Smokercraft. Pyt is right about 24 volt performance.

    My long term goal is to put a 10 KW pack of lithium batteries in an S4 with a 48 volt 4 HP electric outboard motor. That rig would have a range of 25+ miles cruising at 15 kts.

    Kind of like having a Tesla sports car on the water at a fraction of the cost…

    Larry J.

  17. fish

    What’s the real-world range of travel of an electric boat, or kayak?
    The need to recharge the batteries imposes a rather rigid limit, even if you have a way to recharge (e.g. from a car) because recharging takes so much time.
    In contrast, small gas motors consume little fuel, and the S4 can take enough spare fuel on board in cans to last for days.
    And if you happen to travel far, there’s a good chance you’ll find a gas station there.
    OK, so gas motors are noisy compared to electric motors, but only at high RPM. When a water-cooled outboard motor runs at a low RPM, the noise it produces isn’t that loud, IMO, and 4-cycle motors are clean.

  18. Bassman


    Electric range is as far as one can design a vessel for.

    A friend of mine designed the electric motor for a trimaran that crossed the Pacific 3 times using no liquid fuel. He made his own air conditioning and refrigeration while regenerating under sail using the momentum of the boat. There are few gas stations in the Pacific.

    After hurricane Irma, we had no gas in the Keys for days. Our spare cans went to fill land based vehicles. Fortunately, I had two cycle outboards that could use questionable fuel that we scrounged from old boat tanks. Given, longer time without gas, e.g. Puerto Rico’s loss of infrastructure, I would have been charging a battery bank and using my Minnkota to catch fish rather than relying on a daily ration of grilled iguana.

    Many lakes throughout the world will not allow fuel based vessels due to real concerns with pollution. No matter how clean the exhaust may be, people still spill fuel onto the water. Here, the electric motor rules.

    On my guided trips through the mangroves and inshore habitats, the ladies, in particular, love it when I shut off the outboard motor and switch on the pair of Minnkotas to cruise silently through the non-combustion zones. Probably, that is the best reason…

    In my life, a 10+ mile daily range silently cruising at 12-15 kts. in my S4 is an ideal arrangement. Two 50 lb. 2.5 KW lithium battery packs and a 4 hp electric outboard gets me there with electrons to spare. Another pair of similar batteries puts me in distance competition for a yearly electric boat marathon race on the Eastern Shore of Maryland in the Fall.

    But, the real world range of an electric boat is global. The nuclear subs are the best example of that.

    Larry J.

  19. fish


    I thought nuclear subs were submerged steam boats 😀


  20. Pyt Rotary

    Hi Guys,
    You don’t need to remove the bracket for U1 battery size.
    Just lift the battery a bit and push it behind the bracket that way will stay secure there.
    Buy U1 size with handle only, batteries with no handle are a pain in the butt.

    Larry I am very curios about your plan of going to 4Hp Electric.
    What motor do you have in mind?
    What specific batteries?
    I am looking also to increase the range and power of mine for the S4.
    Gas is for long jumps/treks, electric is for fine positions and trolling for me.
    Being able to pull back instantly with electric is really useful.

    Have fun and be safe.

  21. Bassman


    I stand corrected. My knowledge of subs is dated. Still, in WWI and WWII, a lot more big ships were sunk by subs in electric stealth mode than diesel assaults.

    Same goes for fishing. Stealth mode rules when it comes to catching fish. Rox and Pyt have my back on this one.

    Also, in addition to the noise and subsurface exhaust fumes, the smell of gasoline is a real fish turn off. WD-40 lube is the anomaly, though. Because, the lubricating agent is fish oil.

    Each type of motor or propulsion mode is a tool for a given set of circumstances. The whole Wavewalk lineup can be matched to most anyone’s preference on the water. Except maybe sinking big ships or launching nuclear missiles. There, the steam engine powered nuclear subs do rule the seas.

    What other kayak or portable skiff can offer such versatility without the expense of owning a nuclear submarine?

    Larry J.

  22. Bassman


    Hopefully, Yoav and I will agree to disagree on this one…

    Presently, I am looking at the 4.0 long shaft tiller Torqeedo electric outboard with a pair of the 26-104 lithium batteries (over 2.5 KW each).

    No, it is not cheap but I believe it fits the parameters that I am looking for.

    The market advantage of a high performance electric kayak guide service in the Florida Keys is huge. And, I am the closest dealer to the Ocean Reef Country Club Community of sleek high speed yacht tenders and portable shuttlecraft. Why would someone with a 3 million dollar yacht want to put a rubber balloon boat on board when they can have a custom outfitted Wavewalk S4?

    But, note that shallow running of the Torqeedo with the transom locked down may not be a good idea as they are sensitive to damage due to grounding. Thus, a high speed shift to reverse without the transom locked can result in a display of ineptitude.

    I have yet to find an electric outboard motor that compares with the Torqeedo’s performance in forward motion. The Ray electric outboards produced for many years here in Florida probably provide the best daily service for displacement vessels but the Torqeedos rule in the Wye Island Electric Boat Marathon competition where both speed and distance are the challenge.

    Silently running in my S4 at 15 knots for more than 10 miles is enough for me.

    For this year…

    Larry J.

  23. fish


    $4,300 just for an electric motor, without the batteries? 😮 …
    You’d have to sell a lot of Wavewalks to pay for this combination 😀

    Just curious: If 1 KW = 1.3 HP (in the physical world), how do 4 KW translate into 8 HP?
    Is this something that Volkswagen developed? 😉


  24. Bassman


    Most outboard motors in use in the Keys are in the $30 grand plus range. Our local Homeland Security guys use four 300 hp Mercs on their rig. The human traffickers use five!

    According to the power calculator: 4 kw = 5.36 mechanical hp.

    This makes a 55 kg Marinekart run at 30 km/hr. = 18+ mph.

    I’ll be happy w/ 15 mph. Because I reduce my course run by 2/3 using non-combustion zone short-cuts. And, can legally and quickly go where no other vessel can reasonably access.

    Not even Homeland Security with their four 300 hp outboards.

    I plan to sell a lot of Wavewalks…

    Larry J.

  25. fish

    I’ve learned a lot of things on this blog 🙂
    Which makes me think that an S4 outfitted with a steering wheel kit would look really cool…
    I’d have to try it one day,


  26. Bassman

    Yes, Yoav,

    I have been educated, too! Learning and experiencing new things is so great no matter how old we might be.

    That steering wheel would be really cool…

    Really, really cool…

    And, so much fun to steer…

    Larry J. 🙂

  27. fish


    The reason I chose to develop a steering system with a long joystick for the Wavewalk instead of outfitting it with an of-the-shelf steering system with a steering wheel was that the long joystick enables driving while standing or sitting, and driving standing is a blast.
    But a steering wheel has its own, special appeal, undoubtedly – Just put a steering wheel on a dinghy or a Jon boat, and it would look both more “respectable” and more fun 😀


  28. Bassman


    A steering wheel connected to a light Teleflex style cable would work very well on an S4 because you can still easily access from stern to bow on the other side from where the cable crosses.

    We are conditioned to steer vehicles with a steering wheel.

    Plus, the S4 would look really cool with a steering console…

    Larry J.

  29. fish


    I agree.
    Someone who wants to install a steering wheel permanently on their S4 could remove the saddle by drilling out the rivets that attach it to platform that connects the two hulls, laying the steering cables on top of the platform, and installing the saddle back in its place, with the cables popping out from the hole below the steering wheel console.

    And if anyone is concerned about the possibility of rattling noise produced by tips of the old rivets that fall inside the saddle cavity, those could be easily taken out by drilling a hole in the saddle’s tip, “draining” out the tiny rivet leftovers, and sealing the hole with Goop.


    PS — Even cooler: Outfitting the S4 with a steering bar, similarly to a personal watercraft or motorbike! 😮

  30. Bassman


    How did 3 grainy pictures of a battery pack get the image of a white S4 decked out with a steering wheel on a center console placed aft of amidships firmly planted in my brain?

    Won’t happen overnight. Got to add the F/N/R shift and speed control on the console, as well.

    Someone else can outfit their S4 with the steering bar…

    Larry J.

  31. fish

    Ha ha 😀
    Not my fault! It was you who brought up the “cool” Marinekraft.
    I can only guess that this image was planted in your brain by decades of looking at cool runabouts featuring steering wheels, consoles, etc.

    I think the steering wheel would look even better on an S4 featuring a front deck extension such as this –

    S4 with front deck extension

  32. Bassman


    I am kind of partial to the aft steering position as I mostly put the ladies on my boat. Guys can get in their own boat.

    Some folks like move forward to look ahead but I am content with the view from behind.

    Different strokes…

    Larry J.

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