LED Flashlights Brightness?

[Tanda]

I have a flashlight with a CREE XML T6 bulb powered by 1 18650 battery and seems pretty bright and last around 2 hours on a charge. I was looking at getting another with an adjustable beam and here's my question.

If I get a light with 2 batteries vs 1, will it be brighter or just last twice as long? I get enough run time now so if it's not brighter I'm not sure its worth the extra size and extra batteries.

Thanks for your help.

[Whoaru99]

Dunno that it can be said strictly by number of batteries. The light output/lumen specs for the flashlight should tell you if it'll be brighter.

[delcecchi]

I have several LED flashlights that are really bright, and weren't that expensive. They came from Costco, Menards, Fleet Farm, Lowes, among others. They typically use AA or AAA batteries and last a long time. I get a whole canoe trip or more out of a set of batteries.

The LED lenser 7 is a good headlamp. Really bright.

[Tanda]

I have a couple that run AA's also and was looking for something with more distance so I ordered the one off internet and at night it'll cast a good beam for 50 yards or better, and if the beam could be adjusted smaller it would reach much further. I also use this one in the shop and its brightest one I have!(eye's starting to show age..LOL) With buying off internet the lumen output is overrated in there adds so I have no way of really knowing the output. Guess I'm looking for direction from someone that has lights powered by 1 and 2 18650 batteries.

Thanks

[Fishinguy40]

The rule for batteries is, when connecting in parallel voltage stays the same but you increase the amp life. When connecting in series, amp draw stays the same but you increase the voltage.

If you use two batteries instead of one, I'm assuming that they would be in parallel as LED's are rated for a particular voltage. So you would double the amp life and theoretically be able to run it twice as long but the LED should not be brighter. It wouldn't dim as fast, as the batteries begin to drain and voltage drops.

[Walleye Guy]

Like anothe poster stated, brightness of LED flashlights in measured in Lumens. There are some very bright, high-Lumen flashlights out there. Many of these have multiple brightness settings. You will prolong battery life substantially by running the light on the lower brightness settings. Most manufacturers have tables that show how long the batteries will last on each setting.

There are pro's and cons to each battery type. AA's and AAA's are cheap and readily available. The specialty batteries like the 18650 or CR123 are more expensive but generally have more power.

[icehole10]

If you are looking for a really bright led handheld flashlight, check out the Slyde made by Nebo. Our parts dept at work sells them and I have given a few to customers. so far I have been very impressed with them. They have a magnetic base and it actually is two lights in one. 250 lumen flash light and a 190 lumen cob work light, and it runs on 4 AAA batteries.

[Tanda]

The rule for batteries is, when connecting in parallel voltage stays the same but you increase the amp life. When connecting in series, amp draw stays the same but you increase the voltage.

If you use two batteries instead of one, I'm assuming that they would be in parallel as LED's are rated for a particular voltage. So you would double the amp life and theoretically be able to run it twice as long but the LED should not be brighter. It wouldn't dim as fast, as the batteries begin to drain and voltage drops.

Yes this is what I was guessing because from what I've read a t6 led has a max of about 950 lumens depending on what driver is being use to power it. Don't have an idea how to tell what the output on my currant is now but it by far the brightest light I have. Guess when you buy cheaper light you really don't have a clue what you have!

Maybe I'll have to get both 1 and 2 cell lights to know for sure....LOL One for the boat and one for truck?

Thanks!!

[eyeguy 54]

love the cree t6 2000 lumen with the zoom. bought 5 of them and have them in vehicles and around the house. under 10 bucks online and run on 3 triple a batteries. crazy bright! not goof for catching nightcrawlers.... lol

[Whoaru99]

Quote:

If you use two batteries instead of one, I'm assuming that they would be in parallel as LED's are rated for a particular voltage. So you would double the amp life and theoretically be able to run it twice as long but the LED should not be brighter. It wouldn't dim as fast, as the batteries begin to drain and voltage drops.

If it's assumed the load is not increased then you might actually get a bit more than double. However, I think the point of more batteries is more often one of increasing (light) output, while maintaining some semblance of battery life.

[RebelSS]

After lots of research, I just picked up a Nitecore MH10 and MH12 1000 Lumens Tac lights.

YEE GAWDS!! I've had all kinds of duty lights from Streamlight, Maglight, etc, but these are UNREAL! I actually lit up houses at the end of the block in incredible white light. It also sent the roosting birds in the trees flying.

[Iowa_Josh]

Led brightness is all about the current being pushed through the emitter and the bin of the emitter.   Also there are sometimes ratings for raw theoretical lumens and out the front lumens (otf).  Name brand lights are often more realistically rated while $12 "2000 lumen" lights will output way under what they say.  

I have a couple of zoomie lights and I think they are great.   The design is not a high class one in the flashlight world but they work great for the outdoors.   I have a uniquefire t20.   It was cheap but easily throws 2-300 yards when focused in. 

 

Cheap batteries can also throttle your output.