Hi guys, I recently bought an eFoil from China and have two questions I’d love your help with. I’m not a very familiar with DIY, so I’d appreciate your input.
1. Water in the battery chamber From my understanding, the battery chamber is supposed to stay completely dry. However, I often come back from a session with a ton of saltwater in there, leaving the battery half bathing in saltwater. The manufacturer claims this is an “acceptable amount of water,” but it feels like way too much to me.
I’ve checked for obvious leaks:
Cable entries: Look properly sealed.
Gore-Tex pressure valve: The bolt with the membrane seems fine and doesn’t look like the culprit.
The Lid Seal: My guess is the leak is coming from here. As you can see in the attached image, the rubber seal looks really rough and uneven, not smooth. I suspect this is where the water is forcing its way through.
What do you guys think? And if it is the seal, what’s the best way to fix it?
The smaller chamber with water is normal, it’s to cool the ESC I think.
attaching more imgs in my reply because new users can only post 1 image…
2. Water inside the motor housing / lower mast? Should water be allowed inside the bottom section that houses the motor? After rinsing off post-ride, I noticed saltwater weeping out from the seal connecting to the mast (red mark in photo) and around the metal piece at the bottom (blue mark), which I assume is for cooling.
The manufacturer said water in this part is normal. I’m skeptical because saltwater is no joke, and since everything is supposedly closed off, I can’t actually flush the inside with fresh water. Is this actually normal for some designs, or should I be worried? I’m thinking to soak it in fresh water and then properly seal all the sides, but I’m not sure if it’s a good idea.
Of course you do not want water in there, but I know that type of hatches trend to leak.
Also it looks like the battery box itself has at least some amount of waterproofing.
I guess if the battery itself is safe when being in water, there is no real problem.
If that’s the case, I cannot really see from the pictures. If you have any contacts on the outside where you cab measure a voltage, then you have a problem.
No clue about the motor, but it is not unlikely that is as intended/designed.
You are right that the battery has some waterproofing, and I even added more seal just in case. But I’m thinking it’s not designed to have the same level of waterproofing as the ones that have an waterproof outer case. Relying purely on that one line of defense seems a bit sketchy to me. I’ve read that other people with similar efoil models their battery chamber stays dry.
It’s probably the seal as you suspect. The only birds that don’t leak at all are Flite all the other ones leak to various degrees so I have been told . If the battery is waterproof and it’s just a bit of water probably ok. If the compartment is full of water you should contact the manufacturer and try to replace the seal.
Why would the manufacturer go to so much trouble to make a water-tight box for the battery if it wasn’t meant to stay dry? I certainly would not like the battery to be emersed. And use in salt water makes the problem even more concerning. However, I see that you have a sealed 2-pin connector for the battery connection on your setup whereas mine had an open 2-pin connecter for this connector … mine would not have worked if emersed. There also a real risk that fittings leak, so I would have thought it good practice to keep the box dry. I rebuilt some sections of the walls that the rubber seal slots into so the walls were smooth and didn’t tear the rubber gasket. I also applied a smear of vegetable oil to the seal for the same reason. But from what you say, your rubber seal might already be torn?
The reason why they say that some water in the battery box is OK might be because the cells inside the battery “briefcase” are likely encased in resin in an attempt to stop water tracking into this sealed battery unit. But direct contact with salt water can be a problem over time. For example, I soaked the “fully encapsulated” hand remotes in a basin of fresh water after each salt water use but even then I had two die at around 12-18 months. … based on this I would strongly recommend that you flush the battery with fresh water after use. Even my dry batteries developed corrosion around the handle of the briefcase unit … just a function of being in a salt environment, I would suggest.
As an analog to the earlier repair I did on the motor … even though the motor was dried out and remained dry, corrosion set in pushing the motor’s magnets out till they broke = broken motor. At least I got an extra 12 months of use before this happened. I was offered a $ motor unit to repair this but then the manufacturer said they can only sell a $$ whole mast section to get it going again. I’ve decided to use the opportunity to use the board and build my own drive unit with some parts bought when my financial committee accepted such behaviour.
PS … I feel that I would have largely avoided the motor failure issue if I had checked the resistance of the phases of the motor against the body of the motor and picked up the issue early.
