Your lights and humidity


Through the years, I’ve been able to accumulate a number of flashlights. I leave in a tropical country, and in a semi-urban area, and not really directly on the beach.

I’ve store some of my unused lights and accessories on a number of plastic fishing accessory boxes and regular tool and accessories bins.

Somebody brought up to me about concerns on humidity and it’s effect on reflectors, metallic parts, etc.

What I know is that most of our lights are finished to fight corrosion and normal (or even extreme) weather conditions. Some even are rated for at least IPX4, IPX8. Sometimes water droplets do accumulate on the lens during cold weather.

Does this really have to be a ‘great’ concern, that necessitates storing or placing lights inside tight sealed containers with dehumidifying gels?

Doesn’t this defeats the purpose of having them in near-ready condition, especially when preparing for emergency conditions?

Aluminum is not going to be hurt by humidity (just make sure there is no salt present), rubber won’t have much of an issue either. High humidity can rust circuit boards but unless its very high you should not have an issue. It can also rust batteries, but again it would have to be close to 100% or liquid (causing 100% or even super saturated) to cause real problems in the short term.

Anodized aluminum should be fine with salt but unanodized, circuitry and batteries don’t like salt.

Warm moist air will condense on a cold surface.

So if you live in an area of high humidity levels, then sharp temperature differences would need to be avoided if possible to avoid condensation on or within your lights, tools, or other metal items that might rust or corrode.

I live in South Florida which is a tropical climate. The only problem I’ve had with any flashlights are the ones that used alkaleak batteries. Everything else stands up pretty well.

You could buy a dehumidifier. I put one in my basement where I store most of my lights and batteries and it works really well. Was pulling out up to five gallons of water a day out of the air. But even before the dehumidifier my lights and batteries never seemed to have any problems being exposed to the moisture.

any waterproof light is also going to be wet-air-proof

well, we use the small silica gel packs
that are in just about everything we order online.
we do not “recharge” them or anything.
no problems to report.

“ Sometimes water droplets do accumulate on the lens during cold weather.”

Seems strange that this would happen if the flashlight is closed since the O-rings should keep the humidity/water out. I can perceive this occurring when changing a battery in a cold flashlight in a humid environment, but usually the temperature of the flashlight will match the environment.

Another reason could be that the flashlight has water ingress and turning it on will make it apparent.

I would guess that this is not a real life problem but more of a theoretical one. I have lived in south Florida for over 20 years and keep a few lights in the garage. Never had a problem.

Weather here can be just like real tropical weather at times, but we are often normal or even very, very dry, too. I’ve never had any issues with humidity or condensation on my lights as I’ve owned them, but I’ve had a few that apparently had moist air trapped inside from when they were manufactured in China. That usually shows up right away the first time or two that you power up the light. I just remove or loosen the bezel and run it an a low/medium level for awhile, clean the inside of the lens if needed. That usually cures it for good.

If humidity is an ongoing problem inside the light then either it wasn’t constructed with actual waterproofness or there may be damage or deterioration to the o-rings or where they seat, causing very tiny air leaks. Poorly chosen parts for on-board charging ports might also contribute, but most of them are pretty reliably waterproof. Water vapor can actually permeate many waterproof materials and plastics/rubbers but the rate is so very low that it shouldn’t cause a humidity issue. As for reflectors, yeah, water is not good for the aluminized surface on the inside, so avoid that any way you can…trying to clean the reflective surface will almost always damage them, sometimes badly.

Sometime the flashlight is assembled in an environment where the air has lots of humidity, and that water gets trapped in the flashlight. When you take that flashlight to a very cold place and turn it on, the heat from the driver/LED heats the water and causes some of it to vaporize and combine with the air inside the light. Then, as the flashlight sheds heat to the environment and becomes colder, one of the quickest places to become cold is the center of the lens. And that's where the vaporized water likes to condense.

I can’t really see humidity damaging pcb or really anything in the light. I had rust on my computer case before i saw any parts corrode or, god forbid, stop working.
I had cd drives back when I still used such thing from recycled computers that were corroded and still worked.

You’ll be soldering new switch or driver replacement long before humidity does damage.
Batteries are another story though, they have steel cases and should be inspected periodically

Sounds like another very good scenario QReciprocity42.