Fenix LD20 extreme temperature test (In progress...) pics coming soon.

I've decided to test my LD20's reliability at both low and high temperatures.
Pictures coming soon... (deadline JUN,18)

Recently I got the Fenix LD20 R4, I did a quick test, and I put the LD20 in the freezer set about -25 Celsius for 15 min.

Next, I put it in the oven that I warmed up to 60 Celsius. After 10 minutes I checked, and it was fire hot! I'd say at least 150 C. After I took it out, the flashlight had some weird smell, the tailcap was puffed up and the whole light was smoking from the heat. I quickly put it in cold water, then took it apart. Turns out that I have cooked the NiMH batteries and they were stuck in the battery tube, it took me quite some effort to get it out. The lens were full of fog, otherwise the light survived with no noticeable dimming of the LED.













As for the batteries, the sticker on the outside was melted which caused the battery to get stuck and where the 2 batteries contact, some sort of black chemical came out.


Later, I am planning to put it in boiling water, and putting it in the freezer for longer, some drop tests as well was it will be my EDC for my summer trips/hikes which it would be used heavily. I'll report back somewhere around JULY 31.

Sounds like a highly irresponsible (and dangerous) way to test - exactly what again? If your light will work if hot or cold?

shane45_1911 said:

Sounds like a highly irresponsible (and dangerous) way to test ...

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...which is the only method known to man to have some real fun. :devil:

Napalm said:

...which is the only way to actually have some fun. :devil:

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Be that as it may, let's hope his forthcoming pics don't show his house in flames...

I do think putting the torch in an oven was not a good idea. Perhaps boiling a pan of water and leaving it in the boiling water for 15 minutes might be safer as then you won't go over 100C.

I don't think I could bring myself to do this type of test to any of my torches, and how much would you trust them afterwards?

subwoofer said:

I don't think I could bring myself to do this type of test to any of my torches, and how much would you trust them afterwards?

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Obviously, I didn't expect the light to heat up so much, but the LD20 is still working great just like before. Only time will tell if it had survived it with no damage. From the outside, I can't see any damage caused by the heat, I also took the tailcap apart and nothing was melted etc.

As far as safety, I thought NiMH and Alkalines are safe enough to not explode in high temperatures. I would never try something similar with lithiums.

I would definitely not try this again with no safety devices and safe environment. I thought it would only heat to around 60C, but I guess I gotta think through some factors that could affect my "experiment" before I do something.

Otherwise, it's been a day since I've don'e the experiment, I've used it for quite a while since then and the LD20 is still going strong.

This is interesting, and thank you for doing the tests. I recently put a Fenix LD20 Q5 in one of my cars and a LD20 R5 in my other car. The temperature ranges from well below freezing in the winters here and well above 100 degrees farenheit in the summer....which means way over 100 degrees in my cars. I have eneloops in both lights with spare eneloops & spare lithiums in the glove box.

I really like that the extreme temperatures didn't harm the light in your tests, and I believe the temperature wouldn't get hot enough in my cars to melt my batteries. Looks like my set up is a good one....just hope I'm right.

Outdoorsman5 said:

I really like that the extreme temperatures didn't harm the light in your tests, and I believe the temperature wouldn't get hot enough in my cars to melt my batteries. Looks like my set up is a good one....just hope I'm right.

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I'm glad I could help you, although I don't know how the LED is gonna hold up if it's stored at high temperatures for a long time.

You just gave me an idea for another thing to test with my LD20!!!

How can I put post pictures straight from my computer?

.....

Flashlight bodies are made out of aluminum so they can conduct heat away from the emitter. At the same time this means that there is no insulation around the battery tube. Any heat outside the light is going to travel through the body and into the battery compartment.

Why are you testing your lights in this way with the batteries inside? It's not proving anything except that batteries don't like heat. If you try boiling your light with the batteries inside chances are at best you'll just destroy your light. At worst, the light may blow up. I think even NimH and Alkalines blow up if you get them hot enough, especially when cooked inside a confined environment with no place to expand (ie flashlight). If you really want to test your light's ability to take being boiled, try boiling the light without batteries in it. It's much safer.

Also keep in mind that your light is only waterproof because of rubber o-rings protecting the joints. Heat could damage these o-rings or their lubricant and compromise the waterproofing on the light.