How do li-pos handle water?

[derekschultz]

So my flying buddy lost his super cub in the river today. We managed to get it back thanks to a guy that was fishing and had a canoe close by. The plane was right side up in the water and all the electronics were still working properly (didn't let the smoke out lol). He's gonna put all new electronics in it but the battery seems to be ok. TP 1320 3s. It got some water under the heat shrink but it didn't puff or show any signs of damage. I'm gonna let it dry out and then charge it outside just in case something goes wrong. Anyone else have any experience with water logged batteries? Let me know if I'm missing something.

[cbdane]

Each cell has an airtight seal so, in theory, should also be waterproof. The rest sort of depends on the water. A pool (with chlorine and/or other electrically conductive electrolytes) could have caused a short. However, if the conductivity in the river water didn't cause a large enough short to heat the cells and if the cells still tests with a reasonable voltage output, I'd have no concerns about letting it dry out (well), doing a low current discharge capacity test (1C), and then flying.

[Raydee]

Some Lipo's have small pieces of balsa in between every cell. We run Lipo's in our boats and when they get wet we cut the shrink off, remove the balsa to let it dry and then spray the tabs down with electrical parts cleaner. The water isn't the problem but the corrosion from the water will get on the tabs and cause problems. I have yet to see a wet lipo swell or emit sparks unless they get punctured.

[jeffk]

I don't know how bad it is in the batteries we use, but I do know that lithium is seriously explosive if put in contact with water. Even the moisture in the air can cause a reaction. That being the case, I think if there were going to be any issues, you'd have seen them by now. Still, being careful never hurts.

[bullaculla]

hmm. I guess fresh water is okay. but I drove my mini frog with a mamba 8000kv running off a 3S lipo into seawater with dramatic results! :bomb:
salt water isn't good for anything electrical really...

[derekschultz]

I didn't kno that about the balsa between the cells. I haven't had to cut any li-po's open yet. what brand was it that had the wood between the cells?