Does it harm a flashlight to leave it in the car all day?

I was thinking about getting a nice fenix light and was wondering if there is any harm or danger to the flashlight or the batteries inside, leaving them in a hot car most of the time?

I am considering the tk 35 or 41

Thanks

trophybuck135 said:

I was thinking about getting a nice fenix light and was wondering if there is any harm or danger to the flashlight or the batteries inside, leaving them in a hot car most of the time?

I am considering the tk 35 or 41

Thanks

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No it won't damage the light. We do it all the time. But do not leave alkaline batteries in the light cus it might leak; in a matter of fact, don't use alkaline with any nice expensive light. Use Eneloop rechargeable or lithium battery. If you plan to leave in the car for a long time, use lithium. It has a shelve life of 10+ yrs., it won't leak and last a long time.

The first flashlight part to fail from temperature is the battery. After that, the rubber or plastic switch boot and wire insulation. The LED is okay to sit at 100C. If your car gets warmer than that, yikes.

The batteries are another story. Most chemistry happens faster when hot - in this case, you're concerned over cell decay. Physically and electrically, batteries can get weaker over time. Alkaleaks will probably make you unhappy. Energizer Lithium AAs or quality LSD NiMHs will do okay. In extreme heat, NiMHs vent a mostly-water chemical. It's not great for flashlights, but far less corrosive than alkaline goo (Because they have much less of it).

Sanyo Eneloop data sheet states "Storage Condition Less than 90 days -20°C - 40°C / Less than 1 year -20°C - 30°C"

Energizer L91 data sheet states "Storage Temp: -40°C to 60°C (-40°F to 140°F)"

The interior of a car in sunlight can easily reach 60°C (140°F). Some sources say 190°F.

Yamabushi said:

Sanyo Eneloop data sheet states "Storage Condition Less than 90 days -20°C - 40°C / Less than 1 year -20°C - 30°C" Energizer L91 data sheet states "Storage Temp: -40°C to 60°C (-40°F to 140°F)" The interior of a car in sunlight can easily reach 60°C (140°F). Some sources say 190°F.

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Something that can run on lithium AA primary is definitely the way to go for an emergency car light.

If it does harm the flashlight, it's a pretty clear sign that flashlight wasn't worth buying. All tools should be able to tolerate heat, water, and dirt. (I suppose I could add "wind" as the fourth "traditional element", but god help you if you've found a flashlight that can't tolerate a breeze.)

I leave my old Terralux in the car with Alkalines in it and no problem so far, but:

1- It's a 30$ flashlight
2- I don't care if the batteries do leak in it
3- I change the batteries once or twice a year for brand new ones

After spending over 2 years in the car, no problem. Of course, if I bought a brand new 70$ flashlight for the car, I might think twice about which batteries I want to leave inside. I agree that lithium AA's might be a better choice than rechargeables, but knowing myself I probably would stick with alkalines and change them every season instead of once/twice a year.

I can guarantee that the LD20 will survive staying in a car 24/7/365.

Welcome to CPF!

Yamabushi said:

...The interior of a car in sunlight can easily reach 60°C (140°F)...

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The summers out here get hot. I have measured the interior cab temp of my truck and it does indeed get up to 140°F. I've got a loaner Nuwai light that's been baking in the sun for over 6 years and the batteries still fire the light. Just use high quality CR123s if that is your battery of choice. I use SF or Enegizers.

Here is a trick I use to keep my spare cells cool (under 100°F). In my trucks emergancy kit I keep a soft sided cooler with bottled water in it. This is where I store my extra batteries and headlamp. The water acts as a heat sink and I have left a thermometer in it to confirm the max temp remains below 100°F.

kelmo

If you leave your light in a low place that's shaded in your vehicle the tempreture won't go up to damaging levels(well it doesn't in my car).I go to Spain at least twice a year & always hire a car.It gets very hot over there in the summer & i've never had any problems with my lights due to over heating.

kelmo said:

Welcome to CPF!



The summers out here get hot. I have measured the interior cab temp of my truck and it does indeed get up to 140°F. I've got a loaner Nuwai light that's been baking in the sun for over 6 years and the batteries still fire the light. Just use high quality CR123s if that is your battery of choice. I use SF or Enegizers.

Here is a trick I use to keep my spare cells cool (under 100°F). In my trucks emergancy kit I keep a soft sided cooler with bottled water in it. This is where I store my extra batteries and headlamp. The water acts as a heat sink and I have left a thermometer in it to confirm the max temp remains below 100°F.

kelmo

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Thats hardcore, you just cant be to safe..

CR123's do OK in the car as well. The 3v lithium primaries are tough.

DO NOT do it, especially if you can help it. I try to edc a 3 D sized Maglite incandescent. When I can't carry much, I have to leave it in my car, only a few hours at the most. It gets VERY hot here in south Louisiana this time of year. I have used Energizer Max and Now use Duracell Procell. Both have weakened, Energizer Max definitely, the Procell not so much. Industrial batteries must have a better temperature range. Makes me think of my other EDC gear though, how much hell do I put it through.

ericjohn said:

DO NOT do it, especially if you can help it. I try to edc a 3 D sized Maglite incandescent. When I can't carry much, I have to leave it in my car, only a few hours at the most. It gets VERY hot here in south Louisiana this time of year. I have used Energizer Max and Now use Duracell Procell. Both have weakened, Energizer Max definitely, the Procell not so much. Industrial batteries must have a better temperature range. Makes me think of my other EDC gear though, how much hell do I put it through.

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Alkalines are the worst for temperature tolerance. Duracell product data sheets state "Storage temperature: -20°C to 35°C". There is no difference between the consumer and industrial cells.