# 5 cell 18650 holder



## Vancbiker (May 25, 2005)

I wanted something to hold 5 18650 in series for a series connected MC-E running on a bFlex. Cells pop out for charging. Cells will be additionally retained with a velcro strap or a rubber band made of an old innertube. Whole thing will fit small nylon pouch, I'm thinking about a small digital camera case


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## Jim Z in VT (Sep 9, 2007)

That's pretty cool. What did you use for the spacer tubes, and where did you get the battery contacts?

JZ


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## Vancbiker (May 25, 2005)

Spacers are 3/16" aluminum rod drilled and tapped for #4-40 screws. The contacts are from Digikey.



JimZinVT said:


> That's pretty cool. What did you use for the spacer tubes, and where did you get the battery contacts?
> 
> JZ


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## norcom (Feb 22, 2007)

Nice! I've been wanting to try and make something similar. What did you attach the contacts to the acrylic with?


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## Hack On Wheels (Apr 29, 2006)

That is seriously awesome! Any chance you could post up some dimensions and other details?


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## Vancbiker (May 25, 2005)

*Details*

The "end plates" are 6mm thick Lexan. I used a mill to cut "t-slots" for the contacts to slide into and on this one I'll put a dab of epoxy on to make sure they can not slide out. The next ones will have a little bump or ridge in the t-slot to retain the contact. A side benefit to mounting this way is that the contact without the spring is recessed below the surface of the Lexan. This prevents a short circuit if a cell is installed backwards. Each contact is separate so the holder can be wired as series or parallel. All the wiring is through the center of the holder. You can see the solder tabs for the contacts in the second picture. It is 2" in diameter and the batteries protrude slightly ( about 1/16") from that so you can easily remove them for charging. The length is 3 and 1/8". I left a bit of extra length inside so protected cells would fit as well as the unprotected cells in the picture.


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## msxtr (Dec 10, 2006)

Woooooowwwwwww, you have done a great holder!!!!!!!

Greetings - Saludos

msxtr


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## Vancbiker (May 25, 2005)

msxtr said:


> Woooooowwwwwww, you have done a great holder!!!!!!!
> 
> Greetings - Saludos
> 
> msxtr


Thanks for the compliment  . I am starting to work on the light head now.


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## em182 (Feb 22, 2009)

:thumbsup: :thumbsup: outstanding build more and sell them please!!!!!!!:thumbsup: :thumbsup:


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## Vancbiker (May 25, 2005)

em182 said:


> :thumbsup: :thumbsup: outstanding build more and sell them please!!!!!!!:thumbsup: :thumbsup:


Build which, the battery holder or the light head? I have thought about trying to sell the battery holder since Turboferret's biggest is 4 cells.


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## odtexas (Oct 2, 2008)

NIce light housing. I prefer using square aluminum tubing for my builds. 
Looks like your light housing has 1/8 thick bottom and 1/4 inch sides and top. Never seen anything like that before. Also the cuts are very narrow. Are you using a bandsaw for the cuts? Where does the Aluminum tubing come from?


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## Vancbiker (May 25, 2005)

Thanks for the compliment on the light head. It is not tubing, it started as a solid block of aluminum. I am fortunate to have access to a milling machine to use. Your estimates as to the dimensions are really close, good eye! The slots were cut with a slotting cutter on the mill. I would have preferred to make them a bit wider but only had a 1mm wide slot cutter handy and did not spend the time to make multiple cuts in the same slot. I like the tubing idea but was concerned about heat using an MC-E so went with something I could put fins on. I am putting a bFlex in the body and that determined the outer dimensions I am using. I will have a thermal path from the body to the bFlex so it wiil be able to control the ouput if heat gets too high. This manually built light will be mainly to test the basic design. Some friends have seen it now and want some, so I'll make additional ones on a CNC mill. Those will be more refined looking, lighter etc.


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## em182 (Feb 22, 2009)

Vancbiker said:


> Build which, the battery holder or the light head? I have thought about trying to sell the battery holder since Turboferret's biggest is 4 cells.


The battery holder :thumbsup:


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## odtexas (Oct 2, 2008)

Nice CNC work there. The inside corners are so square I didn't think it was CNC. 
I do the tubing due to lack of CNC. Square bodies are easier to velcro to the helmet and bar mount for me. 
You mentioned that you are going to refine your design. I run a few similar housings. 








This is just 1 inch tube with 3/8's bar with slots cut by a table saw bonded to the sides.
I run it with P7 and MC-E emitters. No heat issues.
Version 2 of the 1 inch has T channel sections bonded to the center tube.








Newest light is the one above on the left. It is .75 x 1.25 x .125 inch with slots cut by a table saw. 
All these lights stay cool while riding. Slugs are pressed in with a layer of AAA applied. Your solid light housings should stay even cooler since you won't have the junctions that I do. You could certainly make the housing smaller and lighter and not have a heat issue.
Just showing you some designs similar to yours incase you are still in the design phase.
And again I am very impressed with the cutters on the CNC system you are using there. 
Your design and build options look to be near limitless.
Good luck and keep us updated when you have time.:thumbsup:


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## super-fast (Sep 28, 2006)

Looks amazing. What is the diamater of the holder?


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## Vancbiker (May 25, 2005)

Thanks for the feedback. This first unit was not made on a CNC. I used a chinese built "bridgeport" style manual mill. I used a very small cutter to minimize the radius in the corner of the optic opening. I still had to sand a small matching radius on the Ledil optic to get a nice fit. I feel fortunate that I have access to metalworking machinery. All the DIY lights on this forum amaze me with the ingenuity that is used in the construction. Your MC-E light with the battery along side for scale is great. It's good to know that it has no heat problems despite its tiny size. What do you use for a driver in it?


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## Vancbiker (May 25, 2005)

super-fast said:


> Looks amazing. What is the diamater of the holder?


The battery holder is 2" in diameter. The cells protrude a tiny bit outside that. That provides a spot to get your fingernail on to pop them out for charging.

I am going to work up a price and see if there is any interest for them beyond the few friends that are wanting LED lights after I showed them my project.


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## odtexas (Oct 2, 2008)

I run MC-E at 2S2P with a Fatman mostly. Built a few with buckpucks as well. Run all at 1000mA so 500 going through the 2 channels.
Ran some P7's with a kaidomain 2.8 mA driver. The P7 is parallel so each emitter sees 700 mA. That worked fine. Just couldn't find a small reflector that had any throw.
I now build everything with Fatman drivers. Gives more flexibility in battery choices. I can run 2, 3, 4 cell packs depending on how long the ride is.
With the buckpuck I was stuck with 11.1 or 14.8 battery packs. 
I helmet mount the light and batterypack and just didn't like carrying the extra weight for short rides on the helmet.


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## Vancbiker (May 25, 2005)

OK now I see how you fit into a 1" tube by using a Fatman. I am installing a bFlex and have to deal with it being larger than the star or optic diameter. I am installing a 4S MC-E and will run 750mA on high. This will generate more heat than yours. I don't think my set-up will have any problem with it, but that's what testing is for. I know the MC-Es don't seem to be making as nice a beam as many of the other emitters, but it has to be better than my old Nightrider 10W halogen. I am using a Ledil CMC SS.



odtexas said:


> I run MC-E at 2S2P with a Fatman mostly. Built a few with buckpucks as well. Run all at 1000mA so 500 going through the 2 channels.
> Ran some P7's with a kaidomain 2.8 mA driver. The P7 is parallel so each emitter sees 700 mA. That worked fine. Just couldn't find a small reflector that had any throw.
> I now build everything with Fatman drivers. Gives more flexibility in battery choices. I can run 2, 3, 4 cell packs depending on how long the ride is.
> With the buckpuck I was stuck with 11.1 or 14.8 battery packs.
> I helmet mount the light and batterypack and just didn't like carrying the extra weight for short rides on the helmet.


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## turboferret (Apr 1, 2008)

Nice looking holder, very neat, and the quality of the workmanship looks top notch :thumbsup: 

Similar to what I originally envisaged, but without any access to a milling machine (soon to be changed ) I went for the casting route.

Cheers, Rich


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## Vancbiker (May 25, 2005)

turboferret said:


> Nice looking holder, very neat, and the quality of the workmanship looks top notch :thumbsup:
> 
> Similar to what I originally envisaged, but without any access to a milling machine (soon to be changed ) I went for the casting route.
> 
> Cheers, Rich


The level of ingenuity and variety of abilities on this forum is awesome and inspiring. Your castings mirror what a production molded product would look like. The round 5 cell design would be a tough one to make a mold for. I can only envision a 5 piece "radial" mold, though I am certainly no mold designer. Therefore I mill and make a "toolroom" looking piece.


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## Vancbiker (May 25, 2005)

A bit more progress on the light head. I really need to use a better camera, these are really poor. Could be the user:blush:


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## odtexas (Oct 2, 2008)

Looks really good. 
As long as your beam shots are in focus all will be well.


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## Vancbiker (May 25, 2005)

*Done!*

It works  . I am really impressed how well the bFlex works. The temperature sensing is set to trip at 50C. The housing in still air gets to 42C externally after about 5 minutes of run on high, 750mA and trips the driver to low. The temp sensor is thermal pad mounted directly in contact with the LED mounting surface. A walking pace is enough airflow to keep it below the trip point. It is fitted with a bar mount now and I am starting to make a helmet mount. My crappy camera has no ability to use manual settings so I can't do beamshots with the MTBR settings but they should be the same as any other MC-E with CMC-SS optics. I have a flashlight with a really nice deep reflector that makes a much more focused beam with the MC-E. I would really like to build a version with that reflector but am not willing to scrap a $25 flashlight to get the reflector.


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## Hack On Wheels (Apr 29, 2006)

Freaking sweet! I love it. Nice barmount too, I've been thinking of making some mounts using o-rings to secure them, but hadn't been thinking along quite those lines... The more styles/variations the better, thanks for the inspiration!


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## Jim Z in VT (Sep 9, 2007)

Cool.

Am I correct that the bar mount uses two o-rings stretched around the bars and over the little lugs on the mount? I like it! :yesnod: 

JZ


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## Vancbiker (May 25, 2005)

JimZinVT said:


> Cool.
> 
> Am I correct that the bar mount uses two o-rings stretched around the bars and over the little lugs on the mount? I like it! :yesnod:
> 
> JZ


Yes it uses O-rings. I use Easton carbon riser bars and they begin to sweep up very quickly out of the stem. A single sided mount has never worked well because it has to clamp on the beginning of the bend, so I made this to straddle the stem. The lugs are #4-40 flathead screws, red loctited into the mount. The part in contact with the bars is lined with 2mm thick rubber sheet.


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## videovic (Feb 8, 2016)

You might use a double sided ( or single) circle PCB for the flat end of the cells. the extra surface area in contact and the copper will give less resistance than a point contact. ( my theory), and its cheaper too as you only need the spring connectors not the bubble part. Use the springs for the positive end only.


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