I always highlight to buy this ultra cheap water beep sensor from Banggood or ebay. You can drive it also with 9v batt it’s super simple and warned me several times when I had water issue. Otherwise you are completely blind
Several years ago I tested some device (with transparent cover) for water leaking. I used some food coloring (I don’t know which exact - it was some expired sport supplements 
), when dry - white color, but small amount of water changed it color to bright red and stuck to place where leaking was detected.
Sure, in our scenario it will work only if you have some transparent cover of your case but it’s better then nothing while Banggood shipping your package for 2 months, like my motor…
Yep me too. From the electrical side I have no protection at the moment at all. No fuse nothing. Not even an antispark. Direct into the flier 400a! When i connect I have a spark everytime. For the waterside im on the safe side as everything is doubled waterproof. The hatch and all components are in saperate compartments. So I never had an issue with some water in the board.
No im so blown away how much was damaged here, that I will invest a lot into safety now. Fuse antispark new plugs etc.
Stay safe guys
Yikes that sucks!
Did you build the battery? Any pictures of it? Freshwater or salt water? (likely fresh because it was a lake)
I’ve been following the esk8.news battery builders club. Noticed a few things I could have done better.
Some of the key ones:
Better layout so a balance wire can’t possibly short out to an another group of cell.
Separation between cell groups so the insulation can’t rub off and short.
Fishpaper rings over the positive.
Trim the nickel strips so it isn’t pointy.
I’ve gotten water in my batteries as well, flooded it completely (fresh water). Nothing burned and it actually still was working completely wet… Had to take everything apart and dry and out and redo the shrinkwrap, but it still works well.
That’s a very good theory imo. These wires often run underneath the pack and can easily rub/get disconnected/break free and short against neighbouring cells. This was one of safety upgrade after seeing the wardy incident a couple months ago. Also, having redundancies in your waterproofing is a must! My battery pack is taped with two layers of kapton tape then I added a giant Ziploc bag over it and finally a fireproof/waterproof bag! Edit: I ran the balance wires out of one kapton layer and added electrical tape under and over it to isolate it as much as possible!
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It’s also why I’m propose now a flood sensor in my receiver👍
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Yes that’s an amazing feature! Does it communicate the alert to the remote by vibrating or is it on the display?
Currently I just have stopped the motor like a leash error! But everything is possible!
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I see! I think a vibrating pattern on the remote would be best! No distractions and you still can get back to shore asap.
No wires should eve run underneath or on top of a pack. That’s incredibly bad design. All wiring other than inter-cell connections should run on the sides where there is zero chance of being snagged and with added insulation. This ensures there’s no chance of shorts. Even my busbars are triple insulated and run down the sides.
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Correct me if I’m wrong but the balance wires need to be connected on top and bottom of the pack to reach the different cells. Of course, you should always solder them at the extremeties of the pack and ran through the side but they still will be underneath and on top of the pack.
Run a nickel tab off the negative terminal and bend it over the side. That way the wire can only run off the side and its impossible to short on anything as the side of the cell is also part of the negative terminal.
Fusing your balance wires is actually not that complicated, I have used the fuses 3A below. This reduces the risk of failure when a short happens in one of the wires.
(in my box the cells lay on the side, so the balance wires are on the side of the pack without any pressure/rubbing)
https://nl.mouser.com/ProductDetail/Littelfuse/0471003MAT1L?s=Vv6sT79n3zQdYVF2cfN4GQ%3D%3D
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I run with BMS on-board batteries and no issues. And I had a set get wet and the packs were destroyed but they never caught fire. My battery guy said the BMS actually played a part in controlling the destruction. I will always use a BMS in my battery packs (I have three sets now). New ones have the bluetooth BMS.
Any bms is better than no bms! But thst said I highly suggest read the cells specs and adjust the parameters accordingly! Thermal constrains, discharge rates and voltage cut off they HAVE to have a margin of safety since it is not possible to find out the accuracy of these crappy bms out there! Also I see people never calculate the nickel taps maximum current tolerance! I Always choose or combine them with 25% extra room!
Its funny how we see patterns developing.
Whereas you see potential BMS problems, I see a home built batteries problem. (not sure if this is home built yet)
Im not saying you’re wrong or having a go, and I think there is a bit of a history of BMS problems out there by the sounds of it.
I think the reason I went for a manufactured battery is because there are too many minor mistakes to be made building a battery pack, and the results of those minor mistakes can be catastrophic!
I put my trust in guys that build the packs every day to do it better than I could. Its a lot of energy to go boom under your feet.
I have a BMS on my battery. 
I think if I see this happen to a manufacured battery, Ill be thinking about removing the BMS. Has anybody removed a BMS off a pack? I wonder whats involved?
Which BMS do you use ?
I did, nothing special, just opened it and took the bms out after reading all the BMS problems here. Wondering if I should put it back…
But you still have the balance wires in place?
Should those be fused?
Warning about removing the BMS…
I read about doing that in another forum for Ebikes, and I did remove my BMS…
I dont know if that was the problem or not but my battery did burn up almost taking the garage with it.
3 months renovating the garage… luckily the insurance payed for it…
Just a warning thats what im saying…
I think that the battery should have a BMS connected… that is the way I will go anyway.
Have a nice day everyone!
BR
Magnus
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