Sustained 800 lumens from smaller 18650 light?

atvkilla

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Hi everyone, great info on these forums but researching through all the different lights can be daunting to find the best one for what I need. I'd like to get some ideas from some of you since the knowledge base on CPF is awesome.

I have 5 or 6 various torches, the last one I bought being a Thrunite tn12 which was about 3-4 years ago. With the advance in lumen and runtime technology since my Thrunite, I've been looking to get another more powerful torch.

I'd use it 80% for general purpose around the house stuff, but I'd also like to use it for mountain biking at night. I do have a couple other MTB specific lights like Cygolite and Niterider, but I'd like to try one of these modern torches on my handlebars.

The things I'm hoping for:
- Smaller size, not necesarily EDC size but close to it
- 18650 battery
- Capable of around 700-1000 sustained lumens for at least 1.5 hours. The light would be switched off a couple of times for several minutes within this 1.5 hours as I rest on the trails
- A higher turbo mode for wow factor would be nice, like 2000+ lumens for a short burst.
- Floody beam
- Budget of up to/around $50

I was interested in the Emisar D4v2 and also the Lumintop EDC18, but from the multiple reviews and posts I've seen, I'm not sure it can hold 700+ lumens for an extended period. Just wondering if anyone has any light recommendations for my parameters.
 

Fireclaw18

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D4V2 stabilizes at around 400-500 lumens I think. It won't sustain 700-1000 lumens.
 

atvkilla

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So as a general rule, the larger the light's size and/or the head diameter, the better the heat sinking and run time in a given mode?
 

jon_slider

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Keitho

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I've tried to go with a nice floody handlebar light with 18650, and usually come up short on brightness or runtime. I always end up back at Zebralight for cycling, because I haven't found anything that matches their driver efficiency at cycling brightnesses. For almost a year, I've been running an SC700d on my handlebar for bike commuting on mostly paved bike paths, as well as some night mountain biking. It wasn't quite floody enough, so I have some scotch tape on the lens. I can run it for close to 2 hours on the 945-lumen level, which is plenty bright for my uses when paired with a helmet light. It gets well over an hour at the 1425-lumen level, but it visually isn't that much brighter than the longer-runtime 945 level. If I were doing more technical downhill MTB, I'd either have to run at the max brightness and swap cells a lot, or jump up to a larger bar light. The SC700 isn't perfect, but it competes very well to "cycling" lights as well as 18650 flashlights in terms of the balance between performance, weight, size, and cost.

Sorry that that setup is higher than your budget and is 21700 rather than 18650, but I thought I'd throw it in as a basis of comparison as your search (and mine) continues for the "perfect" light!
 

WalkIntoTheLight

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My Zebralight SC600w MkIV Plus will do 700 lumens without thermal controls kicking in. It's quite small. The Zebralight SC700d would do even better, though it's a bit bigger.
 

atvkilla

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Thanks for all the good advice. I'm thinking maybe I should be looking more into something in the 26650 battery range to get the run times i need with higher lumen output. I have a lot of 18650's lying around so was trying to keep my battery supply all the same but just realized my charger will also handle 26650's.
 
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WalkIntoTheLight

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Thanks for all the good advice. I'm thinking maybe I should be looking more into something in the 26650 battery range to get the run times i need with higher lumen output. I have a lot of 18650's lying around so was trying to keep my battery supply all the same but just realized my charger will also handle 26650's.

You'd be better off going with an efficient driver and LED, than a bigger battery and larger light.

For example, my Zebralight SC600w MkIV Plus will do 700 lumens for almost 3 hours, using a Sanyo GA 18650 cell. It's a small light, and doesn't need to throttle down at that level. (At higher output, it does need to throttle if you're using it at room temp.)

In contrast, I have a Astrolux S43, that can barely maintain 300 lumens without getting way too hot, despite being a larger 18650 light than the zebralight. And it lasts for only about the same time as the Zebralight, despite being less than half as bright. All its inefficiency is going directly into heat.
 

Keitho

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That's a great point about LED and driver efficiency, I couldn't agree more; it's why I keep coming back to ZL. I'll expand on that point of efficiency by mentioning another kind--putting the light where you need it, and not anywhere else. I've been through lights with too small of a hotspot, or too wide of a beam, and both end up being inefficient. For example, I tried a mule on my handlebar once. It was awesome to have a big wall of light in front of me, until I realized how many times I'd have to swap cells on my ride to maintain a sufficient wall of light. When I dimmed the mule down enough to have a long enough runtime, it was way too dim to be useful. It is one of the many fallacies of the lumen-based advertising: all lumens are created equal. The ones that land where you need them are way more important than the rest of the lumens (and the watts needed to produce them). So, getting just the right beam is important, and one of the reasons that an HDS at 250 lumens or my H600c at 579 lumens are such a great tools for so many jobs on which many "2000 lumen" lights would struggle.
 
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