Flooded Battery & lessons learned

I just want to share some bad experience so it can help others avoid the same errors.

As it is my first build and I don’t have experience in batteries, I decided to buy a preassembled & water protected battery pack from KBAccesory via the DHGate web.

The battery is described as 13S10P=130 Samsung cells but after opening it I check that it is 14S6P= 84cells.The BMS is described as 50A but the one in the battery is 30A. And no sign of the cells being from Samsung…
1st lesson: Beware of this supplier…

Then I modified my SUP for a first test making a drawer for the battery. But the cover was not as watertight as I thought
2nd lesson: Test throughfully the waterproofness of your compartments. Water WILL find its way in…

I only allowed some 3 minutes with water in the compartment before emptying it and the battery was in a quite protected plastic cage (which I wrapped in plastic to close any possible opening) and inside it it was protected by the usual heat shrink plastic. Externally It looked as if no serious issue had happened… But the battery didn’t sustain the voltage any longer when connected to the motor or a load. So I had to open it and discovered that it was seriously damaged: rust had completely destroyed some of the welding nickel strips.
3rd lesson: Just some seconds in the water will kill your battery even if it looks good externally, so go back to 2nd lesson

So I’m now back to the beginning… Looking for a preassembled waterproof battery. Something like 14S6P with 150A BMS or something similar that could allow my build to first esurf and then hopefully efoil.

For some reason that I can’t understand nobody seems to sell preassembled batteries prepared for esurf/efoil. Many makers assemble them themselves, but this is not recommended for a newbie with no experience in batteries. And the commercial ones are not waterproof and their BMS doesn’t provide enough Amps to power an efoil motors.

Any recommendation or link where to buy one?

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