HexBright Flashlight Battery Teardown and Replacement

The HexBright flashlight, from 2011, is an interesting little device.  It’s a flashlight with an embedded Arduino for control, so you can reprogram it to do whatever you want.  Which, being a flashlight, mostly involves turning the light on and off and changing the brightness.

This is a companion discussion topic for the original entry at https://www.sevarg.net/2016/09/18/hexbright-flashlight-battery-teardown/

(Comments from Blogger)

2016-09-18 by hjfkmf

Why not just sand down the removable wedge to get that extra mil or two of clearance?

2016-09-18 by Russell Graves

Partly because I didn’t think of it, partly because I might want to use something else in the future.

2016-10-02 by Matt Sargent

What was the battery you get and modified in part 2, and is there a battery out there that is a drop in replacement?

2016-10-02 by Russell Graves

Panasonic 3400mAh from eBay, and I haven’t found a drop in replacement yet.

2016-10-11 by Matt Sargent

I found the following battery and it fits into my Hexbright perfectly.

In order to insert it you must remove the old battery and wedge, then insert the new battery and then replace the wedge. Fits perfectly and tight, as designed.

2016-10-11 by Matt Sargent

By the way, you should use the program “set_and_remember”, it is a modification of the up_and_down program. I modified the up_and_down to have it resume the last saved brightness level and the motion sensing night lite mode is perfect for camping - you can always find the light (the tailcap glows) and when you grab it, the light comes on.

2016-10-20 by dude mcginty

Easily ignorable nitpick of the week: going from 2400mAh to 3400mAh is a 42% (=1000/2400) increase, not 30% (=1000/3400). Another fun read, nonetheless.

2016-10-21 by Russell Graves

Even better then!

@Matt Sargent:
What battery are you recommending as a direct replacement in the HexBright? Your link is no longer working.

I don’t think they’ll see this, as that’s a user who posted prior to the shift to the forum.

If you’re willing to use the same protection circuit, you should be able to use any standard 18650. If you ship me the old one, I could probably do the swap for you, I’ve got some 3200mAh Panasonics laying around.

I reached out to Matt and he sent me a pic and this link to the orbtronic battery: 18650 Protected (10A) battery Panasonic-Orbtronic (FREE Battery Holder) 3400mAh

I have one ordered, will report back with my experience.

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Hey! I am here now! Thanks

I have no idea how that worked, but, welcome!

My Hexbright is still going strong on the replacement battery. It’s still a solution to a problem nobody really had…

The Orbtronic battery works great once you use the trick of removing the wedge, then inserting the battery, then reinserting the wedge. Plug & Play!

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So, I got a replacement battery that fits great, however I’m still having a problem where my hexbright isn’t turning on. I get a red flash on the button when I press it, but no light. After reading another blog, I’m starting to wonder if the 8Mhz SMD crystal on the chip board has broken. Anyone else seen or fixed this problem?


Does the device appear when you plug it in via USB?

+1. Ordered the Orbtronic battery and it brought my HexBright back to life! Thank you for sharing this. :grin:

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I too have a HexBright from the original Kickstarter. Happy coincidence I read Syonyk’s blog! Thanks Matt and digitalman2112 for the Obtronic tip.

Other reports on the HexBright: The whole “weatherproof” thing? It’s legit!

I lost mine back in November somehow. Looked pretty much everywhere, couldn’t find it, gave up. Got a ThruNite for Christmas, so I’ve been OK on the flashlight front.

Today, riding back home, I saw something in the gravel up by the road - it’s a black volcanic ash, gets moved around with the snow when I plow. As I sailed past, I was pretty sure it said HexBright, so I went to go poke, and found my flashlight, half buried in the gravel.

Insides are still dry, and it still works, despite being out in the weather, frozen, snowed on, etc, for a few months!