Topic: What have you bought this week? (Read 313704 times)

warspite · « **Reply #150 on:** February 05, 2019, 03:04:51 pm »

You mentioned you needed pressure release devices, would a pressure cooker release unit work, that's if you can by the relief valve separately, if the thread screws into a standard plumbing fitting that would be a way of connecting it.

Or is car version suitable.

Taranis · « **Reply #151 on:** February 05, 2019, 05:02:22 pm »

Sorry Warspite NOT laughing at you

was a tiger tickle

I like your idea but really I'm thinking of drilling a hole and fitting a small blind rubber grommet. Any excessive pressure will blow it out.

EDIT I just found some in my bits drawer that fit a 7mm hole

Taranis · « **Reply #152 on:** February 05, 2019, 05:28:15 pm »

Actually 6mm

warspite · « **Reply #153 on:** February 05, 2019, 06:06:06 pm »

, I know, tongue in cheek moment, didn't realise it's not that much pressure generated

Taranis · « **Reply #154 on:** February 05, 2019, 09:23:45 pm »

Quote from: warspite on February 05, 2019, 06:06:06 pm

, I know, tongue in cheek moment, didn't realise it's not that much pressure generated

The pressure would only be the result of a faulty battery combusting. The idea is to contain a fire and deny it oxygen in the unfortunate event.
I've ordered another and one of the small 50cal too

warspite · « **Reply #155 on:** February 06, 2019, 10:16:29 am »

Won't any heat just melt the rubber and then oxygen will feed the fire, although the valves on a pressure cooker and a car radiator are still usually rubber, I'm sure there is another type that is all metal, like a bi-metal strip.

another tongue in cheek moment, didn't know tigers tickle you, won't their tongues be quite course

Taranis · « **Reply #156 on:** February 06, 2019, 10:23:12 am »

It was TigerTigers post I was laughing at

The Lipos are in fire-resistant bags as well as the steel box. I expect a defective battery erupting to be controlled. I think the rubber will be ok but I drilled where I did purposely so its directed away from the handle.
Fail to prepare = prepare to fail

aeronut · « **Reply #157 on:** February 06, 2019, 03:21:48 pm »

Taranis - do not under estimate the power of a Lipo 'fire'. Just one going up in a sealed ammo can can be enough to make it bulge significantly, almost to the point of bursting at the seams. One little grommet, as you show, won't do much good at all. The majority of people who use ammo cans just cut away a large portion (25%) of the lid gasket - this allows the gases to escape, but contains the fire. Preventing oxygen from entering, will not make any difference to the initial conflagration at all. There's many videos online of ammo can 'tests' if you care to seek them out.

Taranis · « **Reply #158 on:** February 06, 2019, 03:27:28 pm »

Thank you

grendel · « **Reply #159 on:** February 06, 2019, 03:51:04 pm »

lithium is one of those metals that can burn under water (in fact if you put lithium in water it will catch fire as will sodium and several other similar metals)

Taranis · « **Reply #160 on:** February 06, 2019, 05:48:20 pm »

Bags are cheap as chips from hobby king UK warehouse, under £3 each

So I bought sizes more appropriate to my batteries

JimG · « **Reply #161 on:** February 06, 2019, 06:16:37 pm »

Quote from: grendel on February 06, 2019, 03:51:04 pm

lithium is one of those metals that can burn under water (in fact if you put lithium in water it will catch fire as will sodium and several other similar metals)

If you put a piece of lithium on water (not in as it floats) it will not catch fire on its own. Lithium is not reactive enough to produce enough heat for ignition, it needs a flame to ignite the hydrogen produced before the metal begins to burn. As an ex Chemistry teacher I have done this experiment many times. Sodium and metals lower in the 1st group in the periodic table will self ignite as they are much more reactive.

Jim

John W E · « **Reply #162 on:** February 06, 2019, 06:22:42 pm »

After watching Mythbusters on telly about lipo batteries

if one of these Lipo's goes off in the fireproof bag and which in theory could start a chain reaction - from one to another - in that steel case , if lid is down/sealed, you have just made yourself one hell of a bomb. I like the idea of the fireproof bags, but not in the steel container

remember the laws of explosions - you get a bigger bang if its in a sealed container

Taranis · « **Reply #163 on:** February 06, 2019, 06:29:41 pm »

Video I watched did not ignite all the batteries and they weren't even in bags. I store and maintain my batteries carefully and any extra precautions are a plus rather than a minus in my mind. Ordinarily I keep them in my brick out house but due to overnight temperatures they are indoors.
I'm pretty sure that if one failed in the car I stand a better chance of keeping my car intact than just lying around loose without the protection of a steel ammunition box

John W E · « **Reply #164 on:** February 06, 2019, 06:33:37 pm »

well, if we get your next posting from the moon we know I was right

Taranis · « **Reply #165 on:** February 06, 2019, 06:34:33 pm »

Quote from: John W E on February 06, 2019, 06:33:37 pm

well, if we get your next posting from the moon we know I was right

Taranis · « **Reply #166 on:** February 06, 2019, 06:54:58 pm »

I may change the 6mm grommet to a 20mm

you've given me squeaky bum syndrome

derekwarner · « **Reply #167 on:** February 06, 2019, 09:10:21 pm »

Last time I saw that many Ah

in a rubber lined steel box with internal wooden spacers was from an Oberon Class Submarine....

'the submarine has two batteries, each comprising 224 2V cells (type D7420) giving a nominal 440-V output. ........The cells are designed to deliver 7420 Ahover a period of 5 hours

Surely the work of the Devil ..having so much potential in a tin can

Derek

coch y bonddu · « **Reply #168 on:** February 06, 2019, 09:23:46 pm »

Ok playing devils advocate here carrying time bomb in your car,and carrying so many lipos' should we be informing our car insurance and displaying a hazardous sticker on the back of the car.

Dave

Taranis · « **Reply #169 on:** February 06, 2019, 09:25:15 pm »

They stack them in boxes of hundreds at hobby king towers

They are all in storage mode and I only transport ones that are freshly charged to use that day

Martin (Admin) · « **Reply #170 on:** February 06, 2019, 10:07:50 pm »

Topic cleaned up.... moving on!

Captain Flack · « **Reply #171 on:** February 07, 2019, 03:16:35 pm »

I have heard of people securing plastic bags of sand to the underside of the ammo box lid. In the event of a fire the bag melts allowing the sand to (hopefully) extinguish the blaze.

Martin (Admin) · « **Reply #172 on:** February 07, 2019, 03:26:43 pm »

Anyone actually had a Lipo fire?

Taranis · « **Reply #173 on:** February 07, 2019, 03:36:49 pm »

A club mate had a new battery combust in his car

Dave_S. · « **Reply #174 on:** February 07, 2019, 06:06:49 pm »

I bought a new radio this week, a FlySky 6 channel TX & Rx, all singing and dancing computer radio with 20 model memories, everything adjustable and all for just over 50 quid! I'm currently working through the menu and installing it in last week's purchase, my DF 65 yacht.

I do realise that I could have bought the radio & each as a package and saved a few quid, but I thought my current, non adjustable, radio would do. Turned out I was wrong.

News:

Author Topic: What have you bought this week? (Read 313704 times)