Would you have this emergency torch?

[royfellows]

Just a thought. I have a Fenix torch I won in the aditnow photo competition in 2009, still OK.

 

[Roger W]

.... Food for thought....

One advantage of a tallow candle was that you could always eat it if you were really hungry...

 

[royfellows]

Now I wonder if anyone has tried that with a modern candle?
Some would be daft enough?

 

[Mr Mike]

Is there an ideal battery chemistry for sitting around being very rarely used?

Out of the rechargeable ones (and commonly available) Lithium-ion or Lithium-polymer is still the best regarding self discharge rate.

In case you can use primary non-rechargeables, those shelf life is way longer. Lithium 1.5v and alkalines also good.

The absolute best is Lithium Thionyl Chloride, but as I know it's not rechargeable and got 3.6 volts.

One of the best sat around shelf lives is a Lithuim AA 1.5V - 10 years. Also 3V Lithium Manganese Dioxide. CR123A etc...

The Lithium Thionyl Chloride are OK as well, BUT they need a constant current draw (order of 3-6uA) on them or otherwise they will start to passivate. The passivation is not a problem if they draw current on a regular basis, but if left for months they can stop being able to delivery rated current and voltage.

 

[Paul Marvin]

Just a thought. I have a Fenix torch I won in the aditnow photo competition in 2009, still OK.

I have one of those I also won in 2012 I think it was  :-\

 

[paul]

I would hope you wouldn't have to wait for more than a few hours for rescuers to arrive in the UK, much less a week!

Having a back-up source of light which would last long enough while awaiting rescue and would also be bright enough to use to safely exit the cave if you simply suffered a light failure would be far more useful. There are plenty examples of such a light already available.

 

[Caver747]

The Lithium Thionyl Chloride are OK as well, BUT they need a constant current draw (order of 3-6uA) on them or otherwise they will start to passivate. The passivation is not a problem if they draw current on a regular basis, but if left for months they can stop being able to delivery rated current and voltage.

Thanks for the info. Once I had a Gamma Scout radiation detector and it used Lithium Thionyl Chloride and there was no On/Off switch, it was always on. Now I know why. (At least one of the reasons). I'm also using lithium 1.5v in my multimeter, already for many years, no issues yet. An other bonus is, that apparently those don't leak.

 

[Caver747]

I would hope you wouldn't have to wait for more than a few hours for rescuers to arrive in the UK, much less a week!

Having a back-up source of light which would last long enough while awaiting rescue and would also be bright enough to use to safely exit the cave if you simply suffered a light failure would be far more useful. There are plenty examples of such a light already available.

That's right. Thanks.

 

[Paul Marvin]

We like the  Underwater Kinetics Mini Q40 small and fully waterproof and take 4 x AA,s so you can get some batteries anywhere when out and about.

 

[tomferry]

We like the  Underwater Kinetics Mini Q40 small and fully waterproof and take 4 x AA,s so you can get some batteries anywhere when out and about.

For the prices of your torches I must say I was very impressed  ,the two bare feet sock recommendation was very helpful 

 

[Paul Marvin]

We like the  Underwater Kinetics Mini Q40 small and fully waterproof and take 4 x AA,s so you can get some batteries anywhere when out and about.

For the prices of your torches I must say I was very impressed  ,the two bare feet sock recommendation was very helpful 

Those wet socks are simply the best we have ever had so warm and comfy