Dewalt Flexvolt?

Or may be a bank of capacitors that you charge when stopped or not at full power and use only when taking of for to short speed increase…
That can allow you to run batteries cooler and with lower max amp capacity…
I have no idea of the amount of energy you can store in capacitor of reasonable price/size though…

Option B is to run it at 60v full time and put 4 batteries in with a parallel setup. Would have 16ah at 16s. Granted it would cost around $1000, but you could also run your tools with it when not riding and get access to their warranty on the batteries.

They also have a four battery charger.

Total newbie here. Just starting out. Did the EGO 56v battery work in your build?
Any advice would be appreciated.

I did not try it. Not sure if it would work. I suspect the draw we have would limit it.

Hi all,

I’m digging out this post as I just finished and started testing a setup with 4 dewalt flexvolt 60V 9ah in parallel with a firduo 65162-100kV inrunner and 75-200 ESC that came along. I’m running everything wet thanks to god sent corrosionX and no I didnt die yet from electric shock :zap:.As i’m a carpenter and fully equipped with dewalt tools I thought it would make sense to play with what i already have on shelf and keep everything as versatile as possible using my kitefoil without any modifications. so far i’m only able to pull around 40A out of the pack unfortunately not allowing me to ride faster than 10km/h therefore not allowing me to fly. i’m struggling a bit with Vesc tool being a total rookie in electronic and i think i’m probably missing some parameters in the setup.
dewalt cells rate at 30A discharge. and when using the battery at 60v it is in 15S1P config so full 4 packs in parallel should equal a 15s4p if i’m not mistaking and i should be able then to get a max discharge of 120A? If someone with a good Vesc tool knowledge could point in the right direction that would be fantastic. I can feel i’m nearly there and it is frustrating to be limited by lack of knowledge in a software.
Here are a few pics of the build for those who are interested. I’m yet to have printed the parts that will shield the batteries and hopefully help with reducing the drag when everything still in the water.

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I definitely wouldn’t submerge those battery’s just a PSA. If you google vesc setup there are various tutorials that are easy to follow, it is a bit to follow but once you do it a few times you’ll get the hang of it.

Hi thanks for the tips and concern about the batteries. Seems indeed I’ll have to take the pain and learn vesc tool. About the batteries being submerged I guess you’d worry about shorting the batteries and set everything on fire. I must admit I didn’t dive with total piece of mind the first time even though I ran some test before and soaked them good in corrosionX to protect all the electronics inside. they have been twice in the lake so far. Didn’t fry my balls (yet) :slight_smile: and didn’t even notice any noticeable electrolysis that could have happen in between the +/- poles being in fresh waters. the only thing is that the level of charge led indicators gets trigged when submerged as a tiny bit of current leakage is enough to light them up. My opinion is that any seriously manufactured lithium batteries are really not that easy to set on fire under normal use of temperature and you’d really have to shred them to pieces to expose the lithium to water or manually short the cells with wires to reach point of no return. One good thing coming along with these batteries is that in some way you benefit from the electronics built in that monitors temperature and discharge right of the shelf adding safety at no extra cost. I even think they come with antispark solution too as it never occurs to get a spark when plugging in the batteries to your favorite tool. That being said I’m fully aware that there is always a risk to anything and my example is in no way a guideline for good practice. So here is my waiver :"don’t do this at home people :no_good_man: "

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Why run it like this, it creates a lot of drag and a lot of risks for no reason. Please understand that 60V isn’t a safe wet voltage, it’s ok with dry fingers but no more - a waiver won’t do you much good when you’re dead and your friends and family suffers because of it. Please move the batteries to a dry box and to the top of the board!

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I would not be able to sleep knowing that batteries that were submerged are under the same roof i am…

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Hi Larsb,
I agree with you on the drag at startup using unnecessary battery ressources. Not a problem anymore as soon as you are flying but still you have a point every time you need to water start it reduces your flying time. My goal with that setup was to see if I could pull out something as simple as possible with what I already had. being a carpenter I thought it would be stupid to go and buy more batteries when I already have plenty available in the shop. Already have too many toys in the garage also (boards of all kinds kites wings windsurf…) and thought again I would try to make something versatile and save some storage space.
About the potential risks running everything wet again I agree with you 60v is living on the edge but only if for some reason you decide to grab with both hands positive and negative side at same time which is quite unlikely to happen me not being suicidal and all cables being tucked away out of reach. Direct contact and duration of this contact is where the electric danger lies;
Fire hazard: cells are all water and air tight as long as you dont over heat them I think you run more risks at home leaving your phone charging the whole night on a badly manufactured Chinese charger; The closest I came to burn the house is when my cat peed on my mac charger and it shorted the connectors on the magnet side resulting in frying the cables :rofl: no kidding it really happened to me. (I think pablo_foil will make nightmares after reading this…)

I’ve run ebikes in salty conditions for the last 6 winters, been riding about 15000km per year in total. It’s not so pleasant when you start to hear fizzing between your DC leads due to the wet and salt. Another more efoil related example is that my charge lead was unprotected on my board at first. It only took one trip to the sea to completely erode away the connector so there was a constant leakage current, strong enough to remove some millimeters of material - what you’re doing is not on the edge, it’s over it.

Lethal voltages in wet conditions start at something like 28V, can’t remember exactly but i looked it up at some time after a fizzing incident. A box and some longer leads will remove the risk. As for not touching any current carrying parts: a typical situation is that you have to flip your board in the water since it’s too shallow or need to carry board to your car. It’s bulky and heavy and you will accidently touch the mast and wiring for sure.

OK, i’m done being Mr safety.

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Been testing my setup with 4 dewalt flexvolt 60v 9ah batteries for a few days now and here is my conclusions on why grouping and using powertools batteries to power efoil or any high amp device is a false good idea.
To recap my setup, I wired the 4 batteries in // having the 60v switch pulled in so it created all together a 15s4p pack. Dewalt uses 21700 cells with 30A continuous discharge so I technically could feed my ESC with 120A continuous. Well turnis out this is not as simple as that.

  • 1st issue: in order to water start with a 65162 100kv motor you’d need the full 120A. at least I do me being 100kg and my setup having terrible hydrodynamics when in the water. This is not the best handling discharge rate for the batteries. to overcome this and avoid shortening drastically the life of the batteries you’d need more units in // and well I don’t need so many of that type of batteries in my everyday carpenting job. I would have to end up buying more batteries than I actually really need.

  • 2nd issue: run time foiling is about 10-15mn on that pack meaning that It would lead me buying double as many batteries should I intend to ride longer while first batch being recharged

  • 3rd issue: balancing the packs. For the first runs I charged all 4 batteries to the max using Dewalt’s fast charger that came with before going into the water. My batteries have not had an equal amount of charge and discharge during their life serving their carpentry duties and therefore when plugged // you’d assume the newer units would feed the oldest weakest ones. add to that the strong current demand and again you are totally out of the best use practices. On the last run I had and in order to finish some job before heading down to the lake I used one of the battery in its tool without recharging it before assembling with the rest of the pack… big final mistake. Pulling so many amps out of such an unbalanced pack simply killed the electronics built within each pack. Surprisingly though when testing back home each cells of each pack they all where still in balance within their pack and holding 4,1V after charging them individually. Balance board (I dont think you can call dewalt’s built in elctronics a bms) is dead on 2 of the 4 units meaning I can’t charge them using dewalt’s charger anymore as safety features of the charger won’t allow it.

My conclusion of all that worst practices I meaningfully went through in order to foil using powertools batteries is: DO NOT DO IT. Saddly for our ressources Lithium batteries are being built for an exclusive type of use in order to last and be safe hence forcing us to have in our homes unnecessary redundant power supplies. Can’t wait for a major break through in powering EV.
Until then it will be like Churchill says about democracy, Lithium is the worst form of power source except for all those other forms that have been tried from time to time.…

Note1 on CorrosionX and running everything wet thanks to it: No corrosion noticed anywhere on the new batterie I had just purchased to complete my setup. In comparison my 3 other older batteries had signs of corrosion on the nickel spotwelded strips before I put them to the submerged test (fresh water lake).

Note2 even though CorrosionX seems to allow submerged applications and in the light of my demonstration above next build will be traditional 27100 cells enclosed in the board and watertight because… well, why take unnecessary risks for something that doesn’t even work better. Will definitely still use CorrosionX in addition of watertightness and will treat my powertools with it so I don’t need to tidy after my day’s work and leave all the stuff in wet snow ready for use again the next day or the next spring :scream:

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in addition to

Good points but I am not discouraged, my conclusion are:
1 - don’t mix leisure and professionnal use. The units must be efoil dedicated.
2 - the pack must be correctly dimensioned and charged/discharged simultaneously.
Looking at the 60€ PARKSIDE 20V 8AH battery from LIDL based on 21700 cells, it is easy to cast multiple adapters following YT tutorials.
3 - it should be possible to travel by air with one or two of these units, and ship the rest in small parcels.

There are some issues with mixing and breaking up modules to build a pack - the best option i’ve seen for this is the Grin Ligo batteries (LiGo Batteries - Grin Products - Product Info)
Too expensive of course, i wish they were more reasonably priced, then i’d get a bunch instantly when they get back in stock.

If you just keep to wiring them in series, there should not be any worries, other than capacity and discharge rate?

looks promising on paper but not sure how they can perform in the long run though. You sometimes can have good surprises with parkside though.
Looks like the 8ah is a 5s4p and not sure what the continuous discharge rate is. I’d assume it is definitely not 30A like the dewalts; safe bet is probably 20A max and 10 to 15 continuous. Meaning that to power decently a 6516X motor at 60v and have enough range you’d need at least 12 units of these to make a 15s16p. Quite a fair bit of money to which you have to add the price of a few chargers… in the end a lot of space wasted by the casings and the docks plus the problems I pointed above in a previous post. You may prove me wrong but the more I think about it the more I believe in a dedicated pack assembled with reliable big name cells coming from the same batch (well a bit like everybody does :rofl: hard to reinvent the wheel). I do think though that a solution that allows to split the pack like Larsb pointed (LiGo) is definitely a nice feature to have. I came across a link on the forum for a video of an english guy building packs with individual fused cells in a 3D printed sleeve. Can’t find the link anymore but he was doing it in the same way you pop AAA batteries in your TV remote. I thought that was kinda smart to have such an easy access to each cell. Rises the question of the potential sparks and heat on the contact area should the cell come loose. Contact is only maintained by pressure of the nickel strips used as a spring…

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There is no choice but wiring them both in series and parallel in order to reach operating voltage and capacity and to balance the load at discharge unfortunately…

I think you have a very good point here specially if you could recharge the capacitor bank using the energy that you input while pumping the board. pumping would act like a dynamo on a bike or a piezo on the bbq. Maybe even couple the sinusoidal movement of the pumping with a flywheel to add extra energy storage feature :roll_eyes: on can dream. Not sure how the ESC would handle such a system…

There’s a youtube video where the guy drops all different brands of battery into a bucket of water and EGO 56v is the only battery that still works https://www.youtube.com/watch?v=FgZDYkZlUBI&t=4s

I’ve seen the disassembly videos of the ego battery and they are very well protected from splashes and moisture from outdoor use but I still wouldn’t dream of just letting them get repeatedly submerged–even though I’ve heard anecdotes of people leaving these particular batteries outside all winter under big piles of snow and seeing them work fine in the summer even after all the snow melts through them.

I just got two of the ego 56V 12Ah batteries I’ll be using using to try out a build here to see if they have enough power in parallel to get me up onto foil and whether the total capacity will really be enough to make it worthwhile.

At the very least it’s going to be an upgrade for my electric skateboards where I’m currently using 40V 5Ah kobalt and ryobi batteries in a cheap ‘weatherproof’ plastic ammo box.

Biggest issue with the ego batteries is the size of the plastic casing but the cases appear to come off and go back on pretty easily with a security bit so I can fit two batteries inside my pelican case, use them for a while and then reassemble and put them to other uses as needed.

Ok I just got my two 12Ah ego batteries taken apart and they fit inside one of these Apache 2800 cases from Harbor Freight with Internal Dimensions of 11-7/8" x 9" x 5-5/16" which is equivalent to Pelican 1400 case.

(Pictured is the T120 thruster I am using on my SUP which is basically what led me into these forums)

Looks like a 14s-4p arrangement of Samsung 30Q INR18650 which are rated for continuous discharge of 15 amps and 30A pulse discharge rating. Theoretically that 4p would get you 60A continuous discharge (120A pulse) from each pack. One pack weighs in at about 3kg/7lbs and the height once you take the case off is about 4.8" h x 5.75" x 5.5" (122mm x 146mm x 140mm).

The BMS is potted up pretty good but from other teardowns I’ve seen the BMS is only wired on up the charge side while the discharge circuit just has a sacrificial copper trace that acts as a fuse (of uncertain rating).

Disassembly and reassembly are very easy with a T15 security torx bit on the outside and then 2 phillips head screws holding the connection plate. It’s a bit bulky to fit into a board box but I do like the ability to have a battery that’s not completely dedicated to an efoil build that’s mostly just in my head at this point. These batteries can be used with your lawn/yard equipment, two stage snowblower, and a 3000W inverter system that can serve as backup power in an emergency.

The cells alone would cost about $305 from 18650batterystore and I paid $400 for each of my batteries with 2022 manufacturing markings in “new” condition from some pawn shop on ebay. Each battery arrived in ‘maintenance mode’ at about 35% charge.

At the retail battery price of $550 there are probably better options but I think this will work for me once I get my build underway.