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Re: Li-Polymer Batteries

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Jan Panteltje wrote on 10/20/2017 3:48 AM:
> On a sunny day (Thu, 19 Oct 2017 18:34:47 -0400) it happened rickman
> <gnuarm@gmail.com> wrote in <osb9a9$v5o$1@dont-email.me>:
>
>> 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.
>
> 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.

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.


>> These bags are not made of thick material.  Much better would be this...
>>
>> https://www.ebay.com/itm/171761074567
>>
>> or this...
>
> I wonder if that stuff absorbs moisture...
>
>> https://www.ebay.com/itm/192107744089
>
> Same.

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.


>> 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
>> coated fiberglass which is rated for some minutes at 1100 °F/600 °C which is
>> 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.
>
> I still think you are over-designing a bit.

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.


> I like the flat plastic case for the lights you posted, IF it is really waterproof I would

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.


> not bother with too much 'fire protection' especially with those batteries with protection chip.
> If it does catch fire, then overboard with it... ;-)

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.


> 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.
>
>
>
>
> 0                 0 --> LED
>  \               /
>   \             /
>    \           / carbon rod
>     \         /
>    [  ]     [  ]
> ================= kayak
>
> Could also be one thing with 2 antennas
>
> Danger is it sticks in you eyes.
>
> Experiment.
> Let us know !

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.

-- 

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

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Thread

Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-16 10:16 -0400
  Re: Li-Polymer Batteries Mark Storkamp <mstorkamp@yahoo.com> - 2017-10-16 12:47 -0500
    Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-16 20:49 -0400
  Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 01:30 -0400
    Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 02:28 -0400
    Re: Li-Polymer Batteries Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-10-17 08:13 +0000
      Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 05:21 -0400
        Re: Li-Polymer Batteries Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-10-17 09:47 +0000
          Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 06:18 -0400
            Re: Li-Polymer Batteries Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-10-17 10:26 +0000
              Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 06:33 -0400
                Re: Li-Polymer Batteries Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-17 15:31 +0000
                Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 16:52 -0400
                Re: Li-Polymer Batteries Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-18 07:12 +0000
                Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-18 04:58 -0400
                Re: Li-Polymer Batteries Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-10-18 09:29 +0000
                Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 16:53 -0400
                Re: Li-Polymer Batteries Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-18 07:12 +0000
                Re: Li-Polymer Batteries mike <ham789@netzero.net> - 2017-10-17 12:07 -0700
                Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 17:19 -0400
                Re: Li-Polymer Batteries mike <ham789@netzero.net> - 2017-10-17 20:03 -0700
                Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 23:36 -0400
                Re: Li-Polymer Batteries Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-18 17:49 +0000
                Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-18 16:42 -0400
                Re: Li-Polymer Batteries Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-10-19 09:11 +0000
                Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-19 10:53 -0400
                Re: Li-Polymer Batteries Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-10-19 15:22 +0000
                Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-19 12:18 -0400
                Re: Li-Polymer Batteries Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-19 16:47 +0000
                Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-19 18:34 -0400
                Re: Li-Polymer Batteries Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-20 07:48 +0000
                Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-20 04:56 -0400
                Re: Li-Polymer Batteries Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-20 09:38 +0000
                Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-20 12:47 -0400
                Re: Li-Polymer Batteries Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-20 17:00 +0000
                Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-20 13:45 -0400
                Re: Li-Polymer Batteries krw@notreal.com - 2017-10-20 20:05 -0400
                Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-20 22:54 -0400
                Re: Li-Polymer Batteries krw@notreal.com - 2017-10-20 23:03 -0400
                Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-20 23:23 -0400
                Re: Li-Polymer Batteries krw@notreal.com - 2017-10-21 10:48 -0400
                Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-21 14:53 -0400
                Re: Li-Polymer Batteries krw@notreal.com - 2017-10-21 19:49 -0400
                Re: Li-Polymer Batteries Jasen Betts <jasen@xnet.co.nz> - 2017-10-27 22:47 +0000
                Re: Li-Polymer Batteries krw@notreal.com - 2017-10-27 22:25 -0400
                Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-19 12:51 -0400
            Re: Li-Polymer Batteries Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-10-17 21:05 +0100
    Re: Li-Polymer Batteries TTman <kraken.sankey@gmail.com> - 2017-10-17 16:02 +0100
      Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 17:37 -0400

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