Re: Li-Polymer Batteries

Ok, sorry, I may be wrong about lithium ion batteries. I guess there is a significant distinction between lithium ion and elemental lithium batteries. This is the first document I've seen that makes that distinction. I guess the elemental lithium batteries are not so common, so they are often just not addressed.

But "roll" is not the ultimate advice to give someone in a kayak as not very many actually know how to roll their kayak. We all do the half roll however.

On a sunny day (Wed, 18 Oct 2017 17:12:20 -0400) it happened rickman wrote in :

;-)

On a sunny day (Wed, 18 Oct 2017 16:42:12 -0400) it happened rickman wrote in :

I don't know, seems you are just playing, no idea where you are, but over here nav light for boats need to be certified. There are whole discussions about that in the local boating group (in Dutch), including links to sellers. They even have meetings and test the various things on sale. I know about 3 color LED top lights for sailboats, do not know what you would put on your kayak, left-right would be very close together and very low, you do not get any range like that? None at all with waves?

Anyways, 2 of those bottles like I showed, one left, one right, or some other models, drink content first, wine bottles do not leak, use cork. Round liion may fit through bottle neck, 'recharge' often...

Jan Panteltje wrote on 10/19/2017 5:11 AM:

Lights are not really required for small paddled boats in the US other than needing one you can shine when required to prevent a collision (a good flashlight). Manually paddled boats are covered by regulations for

shine the light which is problematic if you are having trouble. I plan to use a waterproof remote control to be able to manage a red/green/white light in the front and a white light in the rear. Mounting it all on a single mast would be ideal, but kayaks seldom have masts.

Or use something that is more appropriate.

My only real concern with this is how well I can mount the LEDs to shine through the clear part. Initially I ordered some all clear cases intended to secure a cell phone, but one cracked in transit and the gasket on it looked like crap. So I thought something a bit more robust was in order.

Glass will not be used, period. I don't know why you can't see the issue. Imagine the rough handling such containers will have to sustain when they aren't on the boat. It's not like a piece of lab equipment.

On a sunny day (Thu, 19 Oct 2017 10:53:25 -0400) it happened rickman wrote in :

OK, well there are also plastic bottles ;-)

But I was wondering if you could not make something with an existing 3 color sector light, maybe fit the battery battery pack in it? Those exists both with white LEDs and also with R, G, B LEDs like this:

Jan Panteltje wrote on 10/19/2017 11:22 AM:

I have yet to find much that would be appropriate for a small vessel like a kayak. It has to be two parts unless you want the bright white light shining in your eyes. One of the great things about kayaking at night is getting light adapted and seeing things under starlight.

Here is something interesting for enclosing the battery.

It is way larger than what I need, but can be folded over I think. Folding it twice it is small enough. They don't say what it is made of. One way to find out. Thanks for discussing this. I don't think I would have found this bag if I weren't talking to you. The bag will be much better than the other two approaches I found. But then there is the question of how good the bag will be. It's cheap enough I might just do the test you suggested.

On a sunny day (Thu, 19 Oct 2017 12:18:50 -0400) it happened rickman wrote in :

Yes, those bags are often recommended, maybe I should get some too, or not??? I keep the liion cells that I do not use in a plastic icecream box..:

There was a video on youtube about it:

Jan Panteltje wrote on 10/19/2017 11:22 AM:

Once a friend needed to be able to hear the phone ring when she was outside (think of phones connected together by wires, I know, absurd, but that's what we used to use). I put a sonalert in a plastic mayonnaise jar (yes, this was recent enough for food to come in plastic bottles) and she could hear it all over the yard. She left it behind when she moved. It was under the house in the crawlspace, so I don't know if it is still in use today just because it's a PITA to disconnect, lol. Lightning has likely taken it out by now.

Jan Panteltje wrote on 10/19/2017 12:47 PM:

Interesting. Both videos use a lot more battery than I will use and the bag is barely closed. I would be essentially rolling the bag up and depending on the size I use I would be folding the sides over before rolling. These bags are not made of thick material. Much better would be this...

or this...

A meter of the hose is about $22 from Aliexpress. I used an eBay link because you can't shorten Ali links the same way. The hose is silicone

the alleged temperature of a Li-ion battery fire.

The blanket is only $8. It is ceramic fiber rated for higher temperatures indefinitely. It would be enough material for at least three units. I plan to make at least two. I believe I can make a pouch easily using thin gauge wire.

On a sunny day (Thu, 19 Oct 2017 18:34:47 -0400) it happened rickman wrote in :

You have to leave some opening so the smoke can escape and the pressure can be prevented to build up to a point where the bag tares.

I wonder if that stuff absorbs moisture...

Same.

I still think you are over-designing a bit.

I like the flat plastic case for the lights you posted, IF it is really waterproof I would not bother with too much 'fire protection' especially with those batteries with protection chip. If it does catch fire, then overboard with it... ;-)

Other thing I was thinking is to make 2 'antennas' of carbon fiber rod or some flexible rod at the rear of the kayak with in the top red and green LEDs, battery holder at the bottom, needs some screws on an attachment point.

Could also be one thing with 2 antennas

Danger is it sticks in you eyes.

Experiment. Let us know !

Jan Panteltje wrote on 10/20/2017 3:48 AM:

Yes, but some opening is not the gaping holes in these bags. The other video with a bunch of batteries in a latched and sealed ammo case is pretty instructive. Before it broke the seal it actually dented the can with the pressure. But like I said earlier, one cell of Lipo is not nearly as much energy as the videos show.

If I could find similar products to the power bank boards that worked with NiMH, I'd go that route. I believe they actually prefer NiCad in power tools because of the high current. NiMH has too much internal impedance. But this will only draw a couple hundred mA most likely, so it would be a good fit. I would have to roll my own design for the whole thing.

Not sure why you think it will wick moisture and why that is an issue. The cell is sealed so some moisture won't hurt it. If it catches fire moisture will only help dampen the temperature.

Maybe. Many people take their cell phone out on a kayak as a rescue device. It would suck if it caught fire and cause the boat to sink.

Yeah, I already bought one case designed for cell phones and they seem to have a very poor seal material, hard and not terribly compliant. Being water tight is essential. I've had a number of things ruined while kayaking when they were supposed to be water tight, including handheld IP67 GPS devices.

You keep not paying attention. There will be two of these at opposite ends of a 17 foot kayak and the paddler in the middle. There's no way to release it.

No need to experiment. Things sticking up on a kayak are not good. I'm not sure why you would think there is any advantage to this anyhow.

Everything on a kayak wants to be low on the deck, unless you are flying a flag. The red and green lights go on the front to make sure they are seen at all times. They shine from dead ahead to 22.5 degrees past a perpendicular line off each side. The person needs to not be in the way or the light can be missed. They are mounted (along with the white light that shines over the remaining 135 degrees) on the top of the mast of a sail boat because it *has* a mast. On a kayak, a second unit is needed at the rear for the white light. When "at anchor" an all around white light is required. If you were to put the lights on a mast of some sort, they would all be mounted in one unit, not separate units. But a tall thing is a very poor idea for may reasons. Try kayaking sometime, you will learn quickly.

My idea is to use two identical units with something to tell each one which is which (I'm thinking of a magnet operated switch perhaps or an internal switch that you open the cover to set when you mount it on the boat). The only difference is how the units respond to the remote. There are four states - Off, Nav (red/green/white), anchor (all white) and emergency (flashes SOS in Morse code with all lights white). The flashing lowers the duty cycle and extends the duration of the battery. With 3000 mAHr it would run for some 10 hours continuously, or twice or triple that when flashing. But that is just an estimate. It helps in recovering the boat and/or the body.

On a sunny day (Fri, 20 Oct 2017 04:56:50 -0400) it happened rickman wrote in :

So, you contradict yourself, you had fear of water (for the cells ;-) ), now you say they are dry.

The solution is well known, called a PLB, EPIRB, the latest seems to be this:

But I do not think you will be kayaking on the ocean or big water?

Wow

Easy to make a release system with some dyneema line.

Can view it from further away seems a good one to me.

Actually I did, has been 50 years ago or so though. But not at night.

Well just build it, I really do not see the problem, few hours design work. If you have the remote, add an eject button:-) (it would need a separate battery, but wait, why not eject automatically (spring latch) when an IR optocoupler detects smoke or a sensor over-heating in the thing? Now THERE is a design challenge. You can add a phone home, fire crackers, sound alarm, and a speaker giving voice instructions to the crew(you) how to duck for cover. You also need coffee maker, pizza oven, fridge, probably need a bigger battery than just 3 Ah.

How's that for paying attention? Can you keep up? :-)

Here a few days ago the sun was red from the bush fires in the south of Europe, wind from that direction, you could smell it too. When the 100 % eclipse was here around 2000 IIRC even the flowers closed.. very strange.

Jan Panteltje wrote on 10/20/2017 5:38 AM:

I guess you aren't reading any posts that aren't in reply to yours. I have already been educated that Li-ion is not the same as elemental lithium. Regardless, your sentence is not clear. My concern is making a dangerous fire worse, but that doesn't happen getting a lithium ion cell wet.

Why do you feel the need to educate me on things I already know about? These are great devices, but it can still take time to reach you. In an emergency time can be of the essence. The blinking light is a clear distress signal helping to attract attention. Also, EPIRB and PLB aren't nav lights.

Wow???

You keep showing a lack of understanding of kayaks. Get a kayak, paddle it for a few months and get back to me on how practical it is to have release lines running the length of the boat. Also make sure you learn how to do a self rescue.

The lights are to avoid a collision. My hand held light works just fine when I turn it on. I want nav lights so I don't need to worry with the flash light. They don't need to sacrifice practicality for visibility. Visibility will be just fine on the deck.

White water or flat? Did you learn safety practices? Did you learn any self rescues? The deck of a kayak is not a static place. Some styles of rescue involve climbing over the back deck. No poles, etc. allowed.

The receiver and release don't need a battery?

Not so much a design challenge as a question of need. It needs to be safe, there are more than one ways to skin a cat.

Great job!

It was pretty cool but far too short. They should work on making them last longer. Barely time to get one's cloths off and dance.

On a sunny day (Fri, 20 Oct 2017 12:47:16 -0400) it happened rickman wrote in :

Sigh, note what it says about the battery. You DO notice it has none of those protections you are on about? There simply is no space for that. It is simply a waterproof case, and the battery is OK. Study other designs before taking of on a tangent.

Jan Panteltje wrote on 10/20/2017 1:00 PM:

If you want to say something, why not just say it?

They use a primary battery which is NOT Li-ion. It does contain elemental lithium, but this type of cell has a lower risk of fire than most types of lithium cells. But it is a primary type and is not rechargeable.

I do find it funny that you seem to think I am taking of on a tangent.

Not sure where you going with your comment that "they" prefer NiCad in power tools. "They" (manufacturers) make almost[*] 100% LiIon tools these days. LiIon is a hands-down winner in this application, even though they scare you.

The context was compared to NiMH.

Gotcha. Is anyone still making NiCD or NiMH tools? I haven't seen any in a long time.

Don't know. It's been too long since I dug into hand tools much. I remember having an RC boat which ran ok on alkaline cells. Then I got rechargeables for it and it TOOK OFF like a rocket. Seems the lower resistance of the NiCd made a big difference. But it only ran for five minutes, lol.