Page 1 of 4 1234 LastLast
Results 1 to 50 of 197
  1. #1
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94

    4 x 18650 Battery Adaptor

    Guys,

    Taking inspiration from modamag on this thread I am in the process of making something very similar, only not specifically to go inside maglite type torches.





    Would be designed to take 4 18650 cells, either in 4S1P, 2S2P or 1S4P configuration and would have soldered leads for connecting to whatever light you have.

    Thinking about doing a 2 x 18650 holder too, which would be along these lines





    I don't have machining facilities, so would be casting these in polyester resin.

    Wouldn't necessarily be of professional quality, but hopefully more than adequate.

    Idea is that it would be very cheap, and you could stick in whatever 18650 cells you have, and pop them out for charging.

    Anyone interested in some?

    My other threads on the subject are here (Candle Power Forums) and here (Single Track World)

    Cheers, Rich

  2. #2
    At Work
    Reputation: sxr-racer's Avatar
    Join Date
    Nov 2005
    Posts
    1,661
    I may be interested.

  3. #3
    mtbr member
    Reputation: sdnative's Avatar
    Join Date
    Aug 2008
    Posts
    336
    Nice solid modeling! Looks pretty hard to make w/o a cnc mill however. Guess you will be going the carve from wax and investment cast in resin approach?

    I can't wait for 18650 holders to become available, and for cheap!

    Good luck with the project.

  4. #4
    mtbr member
    Reputation:
    Join Date
    Apr 2006
    Posts
    214
    I'll take 2 of the 4x18650 holders *queues up*

  5. #5
    mtbr member
    Reputation:
    Join Date
    Feb 2008
    Posts
    181
    looks good! what kinda price would you be looking at? (and do you ship to the uk?)

  6. #6
    mtbr member
    Reputation: ortelius's Avatar
    Join Date
    Dec 2007
    Posts
    190
    Quote Originally Posted by SkUG
    (and do you ship to the uk?)
    According to his profile hi is from UK.

  7. #7
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94
    ortelius is indeed correct, shipping to the UK won't be an issue, as that's where I live

    Regarding prices, haven't worked it out fully, but probably in the region of £10-15 ish for a 4xholder.

    I would agree totally - making with a mill, especially a CNC one would make life SO much easier, but doesn't mean it shouldn't be possible without

    I'm hoping the end result will be presentable, might take a few attempts, but I certainly want a few for myself, so fingers crossed I'll get there!

    Will take a couple of weeks, but keep checking for updates here.

    Cheers, Rich

  8. #8
    mtbr member
    Reputation:
    Join Date
    Feb 2008
    Posts
    22
    While you wait, you could built yourself one of these

    DIY battery holder for 18650

  9. #9
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94
    Froberg - that looks nice and simple, had I found that in various searches, I probably would have just made myself some of those!

    Another update on the design front - now that I've found a source for battery contacts, I can make the whole thing without requiring a clumsy bolt through the middle, in much the same way as commercial battery holders designed for AA's and the like.





    This will be much simpler, and worst case scenario will require a little bit of Velcro around the batteries to stop them popping out of the holder.

    The downside, is that the configuration cannot be changed quickly between 4S1P, 2S2P and 1S4P. I would pre-wire the units in whatever configuration was required, and then they could be re-soldered to change if required.

    I think the pros out-weigh the cons though, and it should be much easier to use.

    Any thoughts?

    Cheers, Rich

  10. #10
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94
    And now with some fillets and cut-outs to make it easier to get the batteries in and out





    Cheers, Rich

  11. #11
    aka Chris
    Reputation:
    Join Date
    Jun 2008
    Posts
    113
    Looks excellent - I'll be interested in a couple of units.

    Chris.
    The Novice's LED Light Building Blog

  12. #12
    mtbr member
    Reputation: HuffyPuffy's Avatar
    Join Date
    Jun 2008
    Posts
    890
    Looks nice, will you use spring contacts?

  13. #13
    mtbr member
    Reputation: JohnnyTooBad's Avatar
    Join Date
    Mar 2004
    Posts
    353
    I'll be in the UK for the next week and a half. Can you have one ready for me before I leave on the 9th?

  14. #14
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94
    I had meant to show the spring contacts in one of the earlier images, but accidentally posted a pic of the part, and not the assembly - shown below is the unit with the clips and some dimensions.



    Another suggestion to velcro to hold the batteries in is a bit of inner tube, which would be easier and cheaper

    Johnny, I'm afraid the 9th is pushing it a bit in terms of getting some units complete, I'm still waiting on various materials, and it'll be a bit of trial an error before I'll have parts I'm happy to sell I expect.

    However, it'll only weigh about 30g, so postage shouldn't be expensive.

    Cheers, Rich

  15. #15
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94
    Right, opinion time guys, do we prefer the one on the left or the right?







    Looking forward to hearing your thoughts.

    Cheers, Rich

  16. #16
    mtbr member
    Reputation:
    Join Date
    Dec 2006
    Posts
    293
    one on the right, we will need to use strap anyways.

  17. #17
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94

    New question here.

    Right, I think I'm getting close to a finished article

    I'm never going to please everybody by continually asking what people prefer, so apologies if you aren't as keen on the final iteration as some of the previous incarnations, but I consider it to be an improvement.



    Next question, is if people could measure the lengths of their 18650 cells, and let me know the precise measurement, I'd be very grateful, as I'm aware that some cells are different to others. With some vernier callipers would be perfect, but make sure to insulate them with a bit of paper or suchlike, I don't want to be responsible for melting any measuring equipment

    Cheers, Rich

  18. #18
    aka Chris
    Reputation:
    Join Date
    Jun 2008
    Posts
    113
    Looks good - I've got some Ultrafire protected 18650 cells, so will dig out my digital calipers over the weekend and measure.
    The Novice's LED Light Building Blog

  19. #19
    mtbr member
    Reputation:
    Join Date
    Apr 2006
    Posts
    214
    I vote for the round one. Square one looks to be bulkier.

  20. #20
    mtbr member
    Reputation:
    Join Date
    Feb 2008
    Posts
    181
    Correct me if i'm wrong but don't some 18650's have protection circuits? and therefore are a little larger?
    Surely the open ended version would allow for both sizes, fitting the smaller unprotected by tightening the nut down abit?

  21. #21
    mtbr member
    Reputation: sdnative's Avatar
    Join Date
    Aug 2008
    Posts
    336
    Seriously?!? good luck making these parts bro! They would be hard to mold even for the pros.

    KISS is in order here (keep it simple stupi...)

    Use a 4x C" size battery pack holder which sell for ~$2, and make plastic tubes that slip over the 18650 to make them C's. If they are not long enough, make little aluminum end caps to increase the length. If too short, cut the holders down the middle to widen them. Bigger size, but cheap, fast to make and basically light too.

    Or use PVC plastic pipe etc. to fashion up the array. Candlepower or the like had some posts like this but for AA's.

  22. #22
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94
    The cells which I use have a protection circuit, and are a little longer than un-protected ones. The clips which I am using have a fair bit of give in them, so the plan is to be able to accommodate both protected and non-protected cells, but I wanted to have an idea of a realistic maximum and minimum length which it needs to work for.

    A comment on another forum was where does the protection circuit fit.

    The circuit protection is against over-charging, short circuiting, and over-discharging, which I would have thought would be sufficient. Assuming that you are charging the cells individually, a balancing circuit for ensuring even charge between cells isn't necessary.

    I'm building one for myself, and thought that others might be interested too.

    Obviously it doesn't compare with the type of commercially prepared packs, there is no protection circuit, so if this puts people off, then they should pay the premium of a commercially sold unit.

    sdnative - we'll have to see how successful my attempts at casting these units are - I may be reporting a dismal failure shortly! At which point I'll probably wish I hadn't just ordered 500 battery clips

    Cheers, Rich

  23. #23
    mtbr member
    Reputation: sdnative's Avatar
    Join Date
    Aug 2008
    Posts
    336

    A Holder Source

    I hope you don't meet failure!!

    Mouser.com is a great source for battery holders BTW. They literally have hundreds of different mount options and array setups. All are very cheap ... $1.50-4 for the most part.

    Check em out. And good luck using their search tool ...lol, over 1 million parts

    ...I usually just dl the entire catalog page and search each PDF page by page! Works better.

    They are very professional also.

  24. #24
    mtbr member
    Reputation: JohnnyTooBad's Avatar
    Join Date
    Mar 2004
    Posts
    353
    Quote Originally Posted by SkUG
    Correct me if i'm wrong but don't some 18650's have protection circuits? and therefore are a little larger?
    Surely the open ended version would allow for both sizes, fitting the smaller unprotected by tightening the nut down abit?

    As I was looking at 18650's with protection circuits, I read that you don't want to pack multiple cells together that have protection circuits. I think you'd use a single protection circuit for the whole pack.

  25. #25
    banned
    Reputation:
    Join Date
    Sep 2007
    Posts
    7,939
    Round one looks better... take a cut up old innertube and push the battery pack inside and tie off the ends like sausage in a tube container. Quick, simple, durable, light in weight, done.

  26. #26
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94
    I think protected cells are the only ones which should be used in the holder, so I'll be designing around the longer of the 18650s.

    Onto the next issue, although perhaps I'm jumping the gun a little, but who has a dismantled C2 torch they're able to measure?

    I have some Ultrafire C3s, and an MTE P7, but not a C2. If anyone has both a P7 and a C2, and can tell me if the heads are interchangeable, then I'd be most grateful, as it would save me buying another unit initially.

    I've modelled up a tail unit for the C3 and also how I envisage something for a C2, feedback would be appreciated. Due to the diameter of the C3, there isn't space on the tail to fit both a switch and a socket for external power, so I'm planning on just gluing the cable in on these ones.



    On the C2, it's tight, but looks just about doable with both.



    Any thoughts?

    Cheers, Rich

  27. #27
    aka Chris
    Reputation:
    Join Date
    Jun 2008
    Posts
    113
    Rich, I've one of these C2s - what do you want measuring?

    Chris.
    The Novice's LED Light Building Blog

  28. #28
    mtbr member
    Reputation:
    Join Date
    Feb 2004
    Posts
    45
    If you're looking for sets of two 18650 cells, check out the Black & Decker VPX batteries. They have two 18650 A123 Systems Li-Ions in them. Relatively cheap these days since VPX has been discontinued if you can find them. They also won't blow up as they're the newer 'safe' Li-Ion chemistries.

  29. #29
    mtbr member
    Reputation: HuffyPuffy's Avatar
    Join Date
    Jun 2008
    Posts
    890
    I agree with Todd, the A123 cells are great, I use a pack with the M1 size cells and they deliver a good amount of steady power. The only big issue to be aware of with these cells is that they need a special charger (or a charger with a charging algorithm for a123/LiFePO4 cells). They do not come with protection circuits and they have a lower nominal voltage than LIon (3.2V vs 3.7V IIRC). On the plus side you don't need to worry about them popping and they are only made by one company (so you get consistent quality). You can have a chance of bringing them back after an accidental deep discharge (unlike LIon).

  30. #30
    mtbr member
    Reputation: HuffyPuffy's Avatar
    Join Date
    Jun 2008
    Posts
    890
    Rich, how do you plan to connect the tail to the light head? IIRC they are both female threaded.

  31. #31
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94
    The tail will be connected to the head by a thread, the same as the body would be.

    Just to clarify, my bottom picture is of 2 tail units, one pointing each direction.

    Head has a female thread, body has a male, have to work out exactly what size and TPI yet though.

    Electrical connection for the positive (negative is through the body) may vary somewhat between torches though, so will have to research some more.

    Harpoon, the C2 you've linked to looks exactly the same as the MTE P7, so thanks for the offer of measuring, but I don't think it's necessary.

    Cheers, Rich

  32. #32
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94
    Progress was made over the weekend.

    I finished the pattern for the battery holder (the quality looks appalling, as it's a shiny painted enamel finish, but hopefully shouldn't be too bad in the flesh)



    poured the first part of the mold (AAA batteries to provide location between the 2 parts of the mold)



    and then poured the 2nd part of the mold.



    The moment of truth will be the demold, and seeing if the silicon has any nasty big voids/air bubbles!

    I was hoping to cast my fist finished article this weekend, but the 16 hour setting time of the silicon makes it a rather slow process.

    Cheers, Rich

  33. #33
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94
    Well, you will all be delighted to know that the demould went successfully, especially as I was too impatient to wait for the full 16 hours curing time!

    2 halves coming apart


    The 2 halves


    Quite a few air bubbles on the lower part of the mould


    Due to how I poured the mould, I should have anticipated where the bubbles would be trapped. I've filled these with a tiny amount of silicon, so we should be good for the first cast shortly.

    Cheers, Rich

  34. #34
    mtbr member
    Reputation: kangaroomadman's Avatar
    Join Date
    Nov 2008
    Posts
    25
    Looking good!

    Count me in for a couple!

  35. #35
    mtbr member
    Reputation:
    Join Date
    Jan 2004
    Posts
    169
    What did you make the pattern out of?

  36. #36
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94
    The pattern is mainly made from 3mm card backed foam, and thin cardboard. All carefully cut and glued together. The central tube is formed from a felt tip pen. Quite time consuming, and needs to be very accurate, but nice and simple, and nothing expensive. Lots of PVA glue, and a coating of spray paint, and it came out pretty well. If I was being super critical, it isn't quite as square as I'd like, but should be fine in use. Pretty rigid and durable too, I was surprised that it survived the demould process, so I'll make another mould so that I can cast several holders at the same time.

    Cheers, Rich
    Last edited by turboferret; 12-09-2008 at 04:58 AM.

  37. #37
    mtbr member
    Reputation: sdnative's Avatar
    Join Date
    Aug 2008
    Posts
    336
    Quite the DIYer you are. Nice work! I've used a vibratory table when doing casting and lost form investment casting, works well, but obviously not readily available.

    Did you try tapping the side with something light at all ...light rapid vibration often helps the bubbles travel upward and outward. Or find something that shakes and put it against it.

  38. #38
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94
    I did tap the mould a fair bit, but I think due to the shape, I hadn't fully considered how bubbles would actually escape - they were effectively trapped against a ceiling. Never fear - mould number 2 is currently curing, so we'll see how that turns out!

    Cheers, Rich

  39. #39
    mtbr member
    Reputation:
    Join Date
    Oct 2006
    Posts
    2,786
    Be extremely careful not to introduce air when you mix the silicone. I know...easy to say, hard to do.

  40. #40
    Fists of Ham
    Reputation: TheBigYin's Avatar
    Join Date
    Sep 2008
    Posts
    90
    Hold one of those detail sanders (with the sanding pad removed obviously) against the mould. works just like those vibrating pokers that they use to settle concrete.
    When I die, I want to go like my Grandad, peacefully, in my sleep - not like his passengers - shouting and screaming!

  41. #41
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94
    The big moment for the first pours in polyurethane resin arrived last night, so an update with lots of photos!

    The resin sets remarkably quickly, to the point where you need to work pretty fast.

    Ready for demoulding - you can see some resin has managed to find its way out of the bottom of the mould, as I hadn't sealed it up sufficiently.


    The start of the demould process - was rather tricky as I hadn't used any release compound


    The cast part and intact (big relief) mould


    Bottom end


    Top end showing a few voids - this was due to a combination of not enough runners, and some of the resin seeping out of the bottom of the mould


    Top end in a bit more detail


    With battery clips and batteries installed


    Batteries are a pretty tight fit (mine are protected, but the clips are pretty much as compressed as they'll go, so I'll make a new pattern whcih will be slightly longer, and should be better.


    Total weight with batteries


    Weight without batteries


    Cheers, Rich

  42. #42
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94
    Armed with the knowledge of the first pour, I made a few minor mods to the mould. I added more runners at the top, to make resin filling and air removal easier, and cut up and old inner tube to hold the 2 parts of the mould together more effectively

    Mould all bound and ready to go, with 5 runners


    The 2nd cast item, with only 2 minor air bubbles, pretty happy


    The bottom end looks pretty much perfect


    Still a little bit of paint coming off the mould, but a good coating of vaseline made demoulding and overall finish a lot better


    Moving forwards, I have a 2nd mould currently setting, hopefully fewer air bubbles in this one - I'll find out tonight!


    Cheers, Rich

  43. #43
    aka RossC
    Reputation: ocean breathes salty's Avatar
    Join Date
    Oct 2006
    Posts
    936
    Starting to look really good. It's great to see the project moving along so quickly!

    Count me in for a couple

  44. #44
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94
    Thought I should give an idea of estimated prices at this point:

    Battery pack without cable ~ £12
    Battery pack with cable ~ £15? (with 2.1mm male plug)
    Battery pouch ~ £7
    P7 tail cap (to replace the battery tube) ~ £20 (very rough guess currently)

    Complete package ~ £35 ish

    All would have about £1 postage on top to the UK, a bit more to the rest of the world

    Cheers, Rich

  45. #45
    Spanish biker
    Reputation: msxtr's Avatar
    Join Date
    Dec 2006
    Posts
    732
    turboferret You are a genius!!!

    Greetings - Saludos

    msxtr
    Warning!!! my english is very very bad, sorry.

    Easy DIY led light1
    Easy DIY led light2

    The Beast!!!

  46. #46
    Lets RIDE!
    Reputation: Jim Z in VT's Avatar
    Join Date
    Sep 2007
    Posts
    1,548
    Amazing how fast this progressed from theory to reality.....nice job!

    JZ
    It's not about speed, it's about lack of control.

  47. #47
    mtbr member
    Reputation: turboferret's Avatar
    Join Date
    Apr 2008
    Posts
    94
    Right, after someone on BikeMagic got me worried about crazy currents, I did some tests.

    1 cell = 2.25A


    2 cells = 2.66A


    3 cells = 2.89A


    4 cells = 2.97A


    This was with 3 fully charged 2400mA Ultrafire 18650's reading about 4.15V, and one slightly discharged one (for the 4 cell test) reading 3.9V.

    As I had removed the emitter from my P7 for the test I didn't want to run it for ages due to lack of heat sink, so LED was fired up for about 2 seconds in each test.

    I hope this alleviates any concerns about pulling massive loads and blowing up lights left right and centre!

    Cheers, Rich

  48. #48
    mtbr member
    Reputation:
    Join Date
    Apr 2004
    Posts
    726
    Production light with 4x18650 adapter:

    http://lightonlights.com/product/


  49. #49
    mtbr member
    Reputation: HEY HEY ITS HENDO's Avatar
    Join Date
    Feb 2008
    Posts
    716
    Quote Originally Posted by syadasti
    Production light with 4x18650 adapter:

    http://lightonlights.com/product/

    ewwwwww fugly !!

  50. #50
    mtbr member
    Reputation:
    Join Date
    Apr 2004
    Posts
    726
    Quote Originally Posted by HEY HEY ITS HENDO
    ewwwwww fugly !!
    Its a battery pack, 4x18650 not fully inserted. Form factor isn't going to differ much if you want that.

    It looks like this closed:


Page 1 of 4 1234 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •