Torquedo battery hissing after night in 13’ water

[zachduckworth]

Hi,

My friend dropped their torquedo in 12’ or so of water last night. Long story. This morning I dove and retrieved it. It had fallen apart so that only the cables were connecting the three pieces. When I got it to the surface the battery was warm to the touch and hissing, and the battery case had a good sized crack on it. ñ. We disconnected the battery and it got warmer and is still hissing.
What is the best thing to do in this situation? We have a 4-5 hour sail to get back home. They are going to tie a rope around the battery so they can toss it overboard if it starts to smoke. What should we do once we get it to land? Would a car battery place take it? Thanks!

[SailingHarmonie]

I would consider this an immediate danger to the vessel it was on and the people onboard. It wouldn't be on my boat. But I am a total wuss about fires on boats...

But if you feel the absolute need to carry it home, I'd leave it on a concrete pad--a long distance from anything flammable--until it cooled down and any "activity" stopped. I wouldn't put it in a car to transport it anywhere. Once all signs of "life" are gone, recycle it as Torquedo suggests.

[ChrisJHC]

If you must have it on the boat, put it in a metal bucket or similar and leave it outside in the cockpit (tie the bucket to a cleat).

That way, if you need to get rid of it quickly, it will take no time to heave it over the side.

[zachduckworth]

Solution- put in dinghy, tow!

[senormechanico]

Imho, it should go overboard with a tow line tied to it if you really want to try for a warranty call or an actual recycling.
Why risk the ship?

[wholybee]

Tough call. The safest for the boat is to toss it overboard again, which isn't environmentally friendly or even legal. I think the proper handling is to put it in a metal bucket filled with sand.

Not only might it burst into flames that can't be extinguished, but it could explode throwing burning pieces into the air, so tying a rope around it or putting it in a metal bucket might not be enough. If a burning bit of battery lands on the boat, you're screwed.

Note, that Torquedo batteries are not LFP, but NMC. So, the chance of something bad happening is pretty high, and could very well happen hours or days after being pulled from the water.

[donradcliffe]

Not a tough call at all. Toss it overboard immediately and document with video for any warranty issues.

[Mike32]

On commercial airplanes there is an emergency procedure for an overheated or on-fire lithium battery. They use a big, special purpose bag and fill it with water. The battery goes in the water using fire-proof gloves. So, if you have to keep it, I’d put in a big bucket of water, outside where it could easily be pushed overboard if need be. Keep a constant watch on it. I wouldn’t worry about legality of dumping if it’s on fire and can’t be put out. Captain’s authority prevails.

[SailingHarmonie]

Originally Posted by wholybee

Tough call. The safest for the boat is to toss it overboard again, which isn't environmentally friendly or even legal. I think the proper handling is to put it in a metal bucket filled with sand.

Not only might it burst into flames that can't be extinguished, but it could explode throwing burning pieces into the air, so tying a rope around it or putting it in a metal bucket might not be enough. If a burning bit of battery lands on the boat, you're screwed.

Note, that Torquedo batteries are not LFP, but NMC. So, the chance of something bad happening is pretty high, and could very well happen hours or days after being pulled from the water.

There is a place for environmental care and rigor. But not at the risk of human lives. There is nothing at all tough about this call to me. Ditch it.

You advice to put an overheating battery in sand is a very bad one. That will insulate it, and drive the temperature up higher and faster.

[MikeHoncho]

Chuck it. Don’t follow input regarding keeping it in water or using one of those “safety bags” That’s a big battery and the bags the airlines use are not the ones you see on Amazon. I’m not certain of the actual chemistry of the brand but larger packs will burn underwater if they get to thermal runaway and the products (gas) they produce is ultra toxic.

[Statistical]

The risk of fire is significantly higher for highly charged cells so if you can slowly discharge it in a safe location (not onboard) that would be ideal. A good option would be a power resistor across the terminals but if that isn't an option a headlight bulb also works.

Most torqeedo batteries are NMC not LFP so the risk of fire is significantly higher.