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FX-Sabers Discussion - Including a Gallery of custom sabers. => Data Sheets => Topic started by: eastern57 on November 10, 2009, 06:11:59 PM

Title: DIY Li-Ion rechargeable battery pack
Post by: eastern57 on November 10, 2009, 06:11:59 PM
This is how I make [most of] my Li-Ion packs.  I get the ones that are already protected, so they're easy to deal with.

These are Ultrafire 18500 (18mm x 50mm) with the integrated protection circuit.  And I solder them directly.  No problems (yet, of course).

(https://www.fx-sabers.com/forum/proxy.php?request=http%3A%2F%2Fi306.photobucket.com%2Falbums%2Fnn260%2Feastern57%2FMHS%2520hilt%25206%2FDSC05123.jpg&hash=e018fe25f595c55d574b36fcbd4e272bdfc7578e)


First, these have a little coating (silicon, I think) on the positive knobs, you'll have to sand this coating off otherwise the solder will roll right off.  It's kind of hard to tell, but these have been sanded down... might be able to see the marks...

(https://www.fx-sabers.com/forum/proxy.php?request=http%3A%2F%2Fi306.photobucket.com%2Falbums%2Fnn260%2Feastern57%2FMHS%2520hilt%25206%2FDSC05124.jpg&hash=a67114eb8e372caf61530c9099b894645d4f80fb)


With a hot iron, melt a little drop on the knob.  Hold it for just a second or two so the battery tip can heat up and grab the solder.  Do this for the positive poles one each cell.  *The negative sides don't require sanding, but be careful not to hold it for more than a split-second... you'll see that it flows right on.

(https://www.fx-sabers.com/forum/proxy.php?request=http%3A%2F%2Fi306.photobucket.com%2Falbums%2Fnn260%2Feastern57%2FMHS%2520hilt%25206%2FDSC05125.jpg&hash=14864b78e966eea7e69ce8be860ef3361a4db05f)


For the connection between the batteries, I use a little scrap of 22g to bridge the two.

(https://www.fx-sabers.com/forum/proxy.php?request=http%3A%2F%2Fi306.photobucket.com%2Falbums%2Fnn260%2Feastern57%2FMHS%2520hilt%25206%2FDSC05126.jpg&hash=53c69a3bd813a5b7703d14a602c1ca85b70c7d86)
(https://www.fx-sabers.com/forum/proxy.php?request=http%3A%2F%2Fi306.photobucket.com%2Falbums%2Fnn260%2Feastern57%2FMHS%2520hilt%25206%2FDSC05127.jpg&hash=c7d4f4dd2e447d7ce7619d92dfbb6f4b27a6604b)
(https://www.fx-sabers.com/forum/proxy.php?request=http%3A%2F%2Fi306.photobucket.com%2Falbums%2Fnn260%2Feastern57%2FMHS%2520hilt%25206%2FDSC05130.jpg&hash=bd83c8638da57a3ed6aa7bd7f3683c766ac068b2)


And some leads for the ends as well.

(https://www.fx-sabers.com/forum/proxy.php?request=http%3A%2F%2Fi306.photobucket.com%2Falbums%2Fnn260%2Feastern57%2FMHS%2520hilt%25206%2FDSC05128.jpg&hash=f7a040faeb304fd8de003a98649c76f8b5959dd6)


Lastly, it all gets heat shrunk'ded together.

(https://www.fx-sabers.com/forum/proxy.php?request=http%3A%2F%2Fi306.photobucket.com%2Falbums%2Fnn260%2Feastern57%2FMHS%2520hilt%25206%2FDSC05133.jpg&hash=e85f07b53f8c737965afd702ba83449426903b53)

A few tips:
- Make sure your iron is ready to go (I use a 30w radio shack - works great for my purposes), and rosin core solder makes it easier too

- The wrapping around the battery is heat sensitive -shrink tubing- so if you heat the negative pole too long, you'll see the edges of the wrapping receed

- This is for PROTECTED CELLS ONLY!!!

- I highly recommend that you use a recharge port of some type with this set-up

- Funny thing about those protection circuits: they cut power off entirely when they deplete to a certain level - so don't freak out when your saber shuts off without warning... just plug it back in

Good luck!



eastern57 ;)
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Gil Gamesh on November 10, 2009, 06:24:03 PM
Awesome DIY tut here!  I do this exact thing in my packs, works GREAT!  I've even had good results just using solder on the Pos of 1 batt and the neg of the other and securing them straight together without the use of a small scrap of wire!

I remember at first being REALLY nervous about applying heat to the batteries  ;D
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Jasten Skywalker on November 10, 2009, 06:25:56 PM
This is great! Thanks a lot!
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: eastern57 on November 10, 2009, 06:40:44 PM
You're welcome.  Hope it works out for you!

;)
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: zayne on November 10, 2009, 06:43:25 PM
Thanks, this is very helpful  ;)

will this work only for these batteries, or will it work for other rechargable batteries too?
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: eastern57 on November 10, 2009, 06:48:02 PM
It will work with NiMh too... but if you use Li-Ion, make sure they're protected.
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: zayne on November 10, 2009, 06:49:17 PM
thanks  :)
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Jasher Kain on November 10, 2009, 07:33:10 PM
This is awesome. Thanks so much. 8)
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Walky on January 04, 2010, 03:09:45 PM
awesome tutorial
do you have a recommendation on the best place to purchase these
i see them all over the web from $6.30~$12.00 each
Thanx!
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: eastern57 on January 04, 2010, 03:43:17 PM
awesome tutorial
do you have a recommendation on the best place to purchase these
i see them all over the web from $6.30~$12.00 each
Thanx!

I like these: http://www.lighthound.com/Li-Ion-Protected-Batteries_c_24.html

AW - haven't disappointed me yet.  One tip: don't let the few mah differences sway your decision... get the right battery for the project, and don't skimp on quality. ;)  okay, that's two tips.  ;D

Li-Ions are classified by dimensions: 18650 = 18mm x 65mm, 14500 = 14mm x 50mm, etc...

Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Delmustator on January 04, 2010, 04:00:39 PM
Eastern57,

I build mine pretty much the same way except I use leftover Taperwire for the connection between the batteries. It's 18 awg and flat so you can peel the adhesive backing off, heatshrink it,  and trim the edges to look nice and professional once it's soldered to the battery ends. Unfortunately unless you have some left over from a home theater installation, the stuff is pretty expensive at about $1.25 per foot.

(https://sewelldirect.com/productImages/SW-7719_md.jpg)

But for this application, a little goes a LONG way.. I have extra if your interested...

P.S. I just checked out the link you provided for the batteries. Are those prices per each!? OUCHIE!! I usually get them in a 2-pack for the same price. But I have to wait for them to ship from Hong Kong...

P.S.S. Those AW 3000mAH 18650s are nice. Might have to get some of those..
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: eastern57 on January 04, 2010, 04:52:41 PM
Right on, Del!  I actually use copper foil now, it works great!  And it's like $12 for 100 feet.  I like the AWs because they're more consistant and don't lose their charge... ultrafires do that sometimes. 

And I put those 3000mah ultrafires (not AW), in my k3gr1, and so far I haven't had any problems... I've recharged it; haven't really taken note of any significant run-time change, but at least they're not big red fails. :D
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: bluerolla on January 04, 2010, 11:32:24 PM
thanks for posting this i learned a lot. so protected means it's protected against over charging? so no need to add a pcb?
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Delmustator on January 05, 2010, 04:55:18 AM
correct...
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: JANGO FETT on January 05, 2010, 05:36:22 AM
And I put those 3000mah ultrafires (not AW), in my k3gr1, and so far I haven't had any problems... I've recharged it; haven't really taken note of any significant run-time change, but at least they're not big red fails. :D

I have a set in my Anakin AOTC and have yet to recharge them. lots of runtime!
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: bluerolla on January 05, 2010, 10:47:09 AM
^^Delmustator thanks for your reply!
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: razorsharp192 on January 16, 2010, 09:52:37 AM
looks good, great idea, be good not to have to change the batteries!
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Shuyin_Cho on March 02, 2010, 01:07:20 PM
good info, thanks  ;D

will two of these batteries fit side-by-side in an MHS saber?
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: eastern57 on March 02, 2010, 03:35:43 PM
good info, thanks  ;D

will two of these batteries fit side-by-side in an MHS saber?

nope.  sorry. :(
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Master Dru-Er on March 02, 2010, 11:09:10 PM
But there is a way to make it work.  But it is not as cut and dry as ordering parts.

I cut windows in a MHS Ribbed extension to fit an 18650 dual pack.  Then the battery slot was covered up with a sink tube overlay.   ;) Worked great.  I have a commission formulating in my head using the same idea.  If you choose to pursue this route bear in mind that you must leave enough sink tube-MHS piece overlap so that you can't see the battery.  I want to make it less noticeable by using a grenade section powder coated after being modified.  As well as a black 18650 pack.

Good luck.
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Shuyin_Cho on March 02, 2010, 11:37:19 PM
wow that sounds good, you've given me a few new ideas to consider (always a good thing i think)  :P

Title: Re: DIY Li-Ion rechargeable battery pack
Post by: bluerolla on March 03, 2010, 12:01:18 AM
Hey Eastern57 what size heatshrink do you use for the battery pack? i need to know so i can get the right size. thanks ;D
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: eastern57 on March 03, 2010, 04:37:31 AM
Hey Eastern57 what size heatshrink do you use for the battery pack? i need to know so i can get the right size. thanks ;D

1 1/8"
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: bluerolla on March 03, 2010, 09:25:03 PM
Hey Eastern57 what size heatshrink do you use for the battery pack? i need to know so i can get the right size. thanks ;D

1 1/8"

Right on man thanks!!!
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: SithlordFaust on March 04, 2010, 12:34:08 AM
The only prob I found w/ this method is, if you heat up the neg terminal too long it can desolder the legs on the components of the existing protection board. and I had sanded the coating off and used flux.

happened to me on my latest saber, luckily I had ordered a 7.2 pcb not knowing the cells were already protected, so I took the cells apart and removed the existing PCBs and built them back up w/ the 7.2 board.

but I have a saber from Eastern that Im sure he used this method on and they work perfectly.
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: bluerolla on March 21, 2010, 10:00:04 PM
i wanna put two 14500 sized batteries side by side...what size heat shrink should i get and where would be the best place to buy some. any help would be great.
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Darth Peithos on October 15, 2011, 03:55:11 PM
Nice tutorial! I'm planning on building my first saber sometime in spring next year, but there are some things I'm still considering like: Would it be possible to set-up a pack like this one (in-line instead of side by side) in a MHS-hilt, including a soundboard (i.e. PC or Obsidian USB)?
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: LUMINARA UNDULI on October 15, 2011, 03:55:43 PM
Yup.
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Darth Peithos on October 15, 2011, 04:12:31 PM
Thanks, Luminara. Now I absolutely can't wait to start on it!
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Delmustator on October 24, 2011, 04:47:13 AM
I'm starting to get a pyramid of 18650 Li-Ion batteries on my work bench. Funny thing is, they keep tossing old laptop battery packs into the repo-depot  pile at work. I grab them up and recycle. Usually I'll find a bad or diminished cell inside, either toss it or set it aside. The rest of the cells work fine.

At this rate, I'll be able to build a Li-Ion power motorcycle soon..

P.S. What is the charge time on 50 Li-Ion cells in series?  ;D
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: noyl wendor on October 31, 2011, 10:27:02 AM
 Howdy. I was under the impression that you could not make Li-Ion packs with protected cells. I thought unprotected cells and a PCB were what was needed to build a pack. Unless it depends on battery type/brand.
 My uderstanding was that "protected" cells PCB's would fight eachother during recharge. Or did I completely miss something in this thread?
  ;D
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: scottjua on February 17, 2012, 10:09:52 AM
Howdy. I was under the impression that you could not make Li-Ion packs with protected cells. I thought unprotected cells and a PCB were what was needed to build a pack. Unless it depends on battery type/brand.
 My uderstanding was that "protected" cells PCB's would fight eachother during recharge. Or did I completely miss something in this thread?
  ;D

WAs wondering the same thing..
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: IndustrialAction on February 17, 2012, 10:31:48 AM
You CAN make a pack with protected cells but you remove the protection circuit and just use the tabs for soldering.

EDIT: you can leave the protection circuits in place but I personally wouldn't. I would use a PCB.
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: PhoenixJedi on February 17, 2012, 10:53:39 AM
You CAN make a pack with protected cells but you remove the protection circuit and just use the tabs for soldering.

You dont have to remove the protection circuit. You can use the protected AWs or Trustfires to make a pack without a 7.4V PCB. The built in ones wont interfere really.. The batteries might lose their balance after a couple years, but that can be fixed by doing individual charges again. (I have 2 14670 packs like this, they're still in balance and running strong 1 year later)
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: LUMINARA UNDULI on February 17, 2012, 01:55:17 PM
What PJ said.

YES, you can make a pack with protected cells and yes they work fine.  Keep in mind unprotected cells are becoming more difficult to obtain so eventually we may all have to go to packs made this way, or a removable solution ;).

If you fully charge both batteries on a charger that balances them prior to making your pack, you will have the best possible results and the longest possible life.  We have packs with protected cells that have been in the wild for 3+ years now and still going strong :o.
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: PhoenixJedi on February 17, 2012, 02:03:51 PM
What PJ said.

YES, you can make a pack with protected cells and yes they work fine.  Keep in mind unprotected cells are becoming more difficult to obtain so eventually we may all have to go to packs made this way, or a removable solution ;).

If you fully charge both batteries on a charger that balances them prior to making your pack, you will have the best possible results and the longest possible life.  We have packs with protected cells that have been in the wild for 3+ years now and still going strong :o.

Yes, everyone listen to Lumi. She taught me all her tricks :)
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: ag3nt4877 on February 17, 2012, 06:03:12 PM
Somewhat related question ... Is it safe two use a 2AA battery holder with AW 14500 Protected Rechargeable Lithium Battery and use it as an in hilt charge pack?
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: const on February 18, 2012, 03:14:40 PM
excellent post, now that Tim is stocking even more battery selections!  Just to clarify (better safe than sorry with explodables!) JST connectors would go like normal on the + - leads?
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Sohryu76 on February 23, 2012, 06:09:19 PM
I have a question about building my own battery packs... and I think I have the correct idea in my head, but something tells me I am wrong at the same time.

Can anyone point me to building a 7.4V battery pack in a 2x2 configuration?

I can't convince myself my wiring idea is correct.

thanks in advance!
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: djkibaman on April 08, 2012, 08:48:08 AM
So if i wanted to use protected batteries to make a pack, do i have to charge them up before making them? then does that mean i have to buy a regular charger like  this one first to charge them up? http://www.thecustomsabershop.com/TrustFire-All-in-One-Charger-P346.aspx (http://www.thecustomsabershop.com/TrustFire-All-in-One-Charger-P346.aspx)
because i already have nice li-on charger that i use for my helicopters, is there way to use it to charge these batteries?
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: QUI-GON JINN on April 08, 2012, 09:14:14 AM
So if i wanted to use protected batteries to make a pack, do i have to charge them up before making them? then does that mean i have to buy a regular charger like  this one first to charge them up? http://www.thecustomsabershop.com/TrustFire-All-in-One-Charger-P346.aspx (http://www.thecustomsabershop.com/TrustFire-All-in-One-Charger-P346.aspx)
because i already have nice li-on charger that i use for my helicopters, is there way to use it to charge these batteries?
When making ANY type of Li-Ion battery pack,  you really do need to fully charge each cell in the pack prior to making the pack.  If you don't,  you run the risk of having an unbalanced pack,  as was mentioned above.
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: djkibaman on April 08, 2012, 09:50:43 AM
Ok i know that i have to charge them up first before making the pack but I'm trying to find out if i have to buy this one to charge them up first
http://www.thecustomsabershop.com/TrustFire-All-in-One-Charger-P346.aspx (http://www.thecustomsabershop.com/TrustFire-All-in-One-Charger-P346.aspx)
or is there a way to charge the batteries with the one i have already like this one before making the pack?
http://www.thecustomsabershop.com/TrustFire-All-in-One-Charger-P346.aspx (http://www.thecustomsabershop.com/TrustFire-All-in-One-Charger-P346.aspx)


Title: Re: DIY Li-Ion rechargeable battery pack
Post by: QUI-GON JINN on April 08, 2012, 09:58:59 AM
Ok i know that i have to charge them up first before making the pack but I'm trying to find out if i have to buy this one to charge them up first
http://www.thecustomsabershop.com/TrustFire-All-in-One-Charger-P346.aspx (http://www.thecustomsabershop.com/TrustFire-All-in-One-Charger-P346.aspx)
or is there a way to charge the batteries with the one i have already like this one before making the pack?
http://www.thecustomsabershop.com/TrustFire-All-in-One-Charger-P346.aspx (http://www.thecustomsabershop.com/TrustFire-All-in-One-Charger-P346.aspx)



Uh,  you asked "do i have to charge them up before making them?"  

And those links are the same charger....I'll assume the other one you meant to post is this one:
http://www.thecustomsabershop.com/37V-148V-Li-Ion-Smart-charger--P129.aspx

The answer to that question is yes,  you can use that charger to charge the cells,  but you'll have to make an adapter to charge them with.  I used a single AA holder from Radio Shack with a 2.1mm charge port attached to it.  Another way to do it is just solder some wires to the ends of each cell (you're going to do that anyway to make the pack) and just use the alligator clips that came with the charger to charge them (you may have to charge them one at a time).
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: djkibaman on April 08, 2012, 10:10:05 AM
Thank u QGJ i think i'll use the 2nd advise btw sorry for incorrect link. This is the one i own but i guess it's same difference now
http://www.redrockethobbies.com/Thunder-Power-TP610C-1-6Cell-LiPo-0-25-10A-p/thp610.htm?29184 (http://www.redrockethobbies.com/Thunder-Power-TP610C-1-6Cell-LiPo-0-25-10A-p/thp610.htm?29184) these would work also right?
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: LUMINARA UNDULI on April 08, 2012, 10:47:19 AM
Depends on what adapter came with it.  I find using one where the batteries pop in is easier for battery packs, particularly if you are making several.
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: djkibaman on April 08, 2012, 11:48:22 AM
So would these batteries be ok to make a rechargeble pack? becuase under description it recommends not to be used as rechargeble pack.
http://www.thecustomsabershop.com/TrustFire-Protected-37V-900mAh-14500-Lithium-Battery-2-Pack-P342.aspx (http://www.thecustomsabershop.com/TrustFire-Protected-37V-900mAh-14500-Lithium-Battery-2-Pack-P342.aspx)
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: LUMINARA UNDULI on April 08, 2012, 11:54:09 AM
I am not fond of those particular batteries, personally.  They have overstated mah and usually the runtime is less than expected.  However the reason why that disclaimer is there is because the "party line" is to only use unprotected batteries with a seperate 7.4V pcb for battery packs.  On the other hand, plenty of people use protected cells for packs and they work just fine.  It is really up to you. 
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: djkibaman on April 08, 2012, 12:41:13 PM
Thnx Lumi 4 enlightening me with ur wisdom. Which batteries do u recommend?
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: LUMINARA UNDULI on April 08, 2012, 12:52:30 PM
For a less expensive battery, I like these: http://www.dealextreme.com/p/trustfire-protected-14500-3-7v-900mah-rechargeable-lithium-batteries-2-pack-26124 , for whatever reason the flame colored ones seem to perform better than the blue jackets.  For a better battery, I recommend these: http://www.lighthound.com/AW-14500-Protected-Rechargeable-Lithium-Battery_p_96.html .
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: PhoenixJedi on April 08, 2012, 01:58:06 PM
For a less expensive battery, I like these: http://www.dealextreme.com/p/trustfire-protected-14500-3-7v-900mah-rechargeable-lithium-batteries-2-pack-26124 , for whatever reason the flame colored ones seem to perform better than the blue jackets.  For a better battery, I recommend these: http://www.lighthound.com/AW-14500-Protected-Rechargeable-Lithium-Battery_p_96.html .

TCSS has these in stock as well!
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: LUMINARA UNDULI on April 08, 2012, 02:50:47 PM
That's right, I forgot TCSS is now stocking AWs :P, linky: http://www.thecustomsabershop.com/AW-Protected-14500-750mAh-P692.aspx .
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: PhoenixJedi on April 08, 2012, 03:22:26 PM
That's right, I forgot TCSS is now stocking AWs :P, linky: http://www.thecustomsabershop.com/AW-Protected-14500-750mAh-P692.aspx .

They have the Trustfires too!
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: scottjua on April 08, 2012, 09:27:18 PM
Somewhat related question ... Is it safe two use a 2AA battery holder with AW 14500 Protected Rechargeable Lithium Battery and use it as an in hilt charge pack?


This... I want to know. From another post, I was trying to get a grasp on this..

So if I have a 2 AA holder, with the 14500s in it, and wire a recharge port to the +/- wires... can I plug a charger port into the charge port and it will charge them? The DO NOT NEED to be soldered directly to the batteries????
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: PhoenixJedi on April 08, 2012, 09:49:32 PM
You have to balance charge the batteries first to do this. One at a time charge them to max... Then this can be done safely.

Somewhat related question ... Is it safe two use a 2AA battery holder with AW 14500 Protected Rechargeable Lithium Battery and use it as an in hilt charge pack?


This... I want to know. From another post, I was trying to get a grasp on this..

So if I have a 2 AA holder, with the 14500s in it, and wire a recharge port to the +/- wires... can I plug a charger port into the charge port and it will charge them? The DO NOT NEED to be soldered directly to the batteries????
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: scottjua on April 16, 2012, 01:10:59 PM
Thanks! Works like a charm!

You have to balance charge the batteries first to do this. One at a time charge them to max... Then this can be done safely.

Somewhat related question ... Is it safe two use a 2AA battery holder with AW 14500 Protected Rechargeable Lithium Battery and use it as an in hilt charge pack?


This... I want to know. From another post, I was trying to get a grasp on this..

So if I have a 2 AA holder, with the 14500s in it, and wire a recharge port to the +/- wires... can I plug a charger port into the charge port and it will charge them? The DO NOT NEED to be soldered directly to the batteries????
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Lord Bane on May 23, 2012, 10:17:11 AM
Let me know if I missed anything because I didn't see it here on the thread. I have two questions.
1. What is the difference between Ultrafire and Trustfire?
2. I have recently had issues with charging my 7.4 trustfire 14500 packs. I plug them in to the recharge port and the charger led rapidly blinks red. I looked on the Tenergy site and it's telling me I have a short circuit. I have charged the batteries individually, wired them up and same issue.  I have been making packs for a while now and had no problem up until now. What do you guys think it is?
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: PhoenixJedi on May 23, 2012, 10:50:59 AM
Need pictures.
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Lord Bane on May 23, 2012, 03:27:52 PM
Here is a video of what I'm talking about.

http://i1028.photobucket.com/albums/y344/solidsnake1967/84f3bb6e.mp4
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Psab Keel on May 23, 2012, 06:21:46 PM
So it is possible to use 2 qty. 3.7 volt Li-Ion Protected cells wired in series to make a 7.4 volt battery pack.  I was also under the impression that the protection circuits in each cell would cause conflict between the batteries.  I only have experience making two Li-Ion rechargeable packs.  The first was with protected cells and the other with unprotected cells with a PCB added during my construction of the pack.  I had trouble with the first and I assumed that the protection circuits in both was what caused the problem.  Though upon reading this thread I now know that I didn't charge them individually before I constructed the pack to ensure even charging, so that could have been the problem.  The pack made with the PCB I added seemed to work just fine.
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: PhoenixJedi on May 24, 2012, 12:23:06 AM
I meant of the batt pack and how its wired. Also check the total voltage.

Here is a video of what I'm talking about.

http://i1028.photobucket.com/albums/y344/solidsnake1967/84f3bb6e.mp4
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: scottjua on May 24, 2012, 01:59:14 PM
Question:

Can I take the two trustfire 14500s I got from TCSS... charge them one by one first, then wire them together, heatshrink them, and voila I have a battery pack???

Is it this simple?
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: LUMINARA UNDULI on May 24, 2012, 02:45:05 PM
Pretty much :D.
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Gil Gamesh on May 31, 2012, 06:17:29 PM
Question:

Can I take the two trustfire 14500s I got from TCSS... charge them one by one first, then wire them together, heatshrink them, and voila I have a battery pack???

Is it this simple?

week late, but yup, it's that simple.  Some prefer to use the PCB's, but personally I've always made packs like how you said, and have only had an issue once where one of the batteries got borked.  Pretty good ratio of success to fail over the last few years!
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: smaneesint on February 28, 2016, 10:41:45 AM
I know this thread has been posted since 2009, but I wanna thank you for making this topic! As an overseas buyer, I cannot order any completed battery so I'll have to make one myself.  :smiley:
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: mikestar007 on February 28, 2016, 11:29:03 AM
I'm actually curious now that's it's been a few years , have those packs with individual protected cells in them maintained their balance and runtime?
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: eastern57 on February 29, 2016, 04:37:50 PM
Ooh, good question, Mike.  The longest standing project that I have right now is my iron man hilt (jan 2012), it still runs great with the AW 14500 pack.  I have other projects that use AWs from even earlier, but I have forgotten which hilts they are in.  Regardless, the fact that I've lost track should be a testament to the fact that I can rely on them to work - even after I've pulled them out of old project hilts. 

On the other hand, Trustfires and Ultrafires eventually fizzle out. They either lose the ability to charge, or their output goes to crap.  But AW/Panasonic seem to go the distance.
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: mikestar007 on February 29, 2016, 07:15:39 PM
That's great! I was a little on the fence about making a pack with two protected cells for my saber. Thanks for the reassurance.
Title: Re: DIY Li-Ion rechargeable battery pack
Post by: Withengar on March 05, 2016, 02:12:47 PM
Hello, I am trying to build a 7.4V pack and i've question.
In Azmaria Dei guide for building a Li-Ion battery Pack it is stated that discharging a Li ion cell to a value below 2.7V increases the risks of damaging the cell. Reading through some PCB data sheets I've noticed that they either feature an over discharge voltage value of 3V or a much lower value between 2.2 or 2.5. So if a 3.0V is used the pack will not discharge completely and more frequent recharges will be required, but there is (almost) no risk of damaging the pack, while if the 2.2-2.5 is used the pack will last longer before it runs out but the excessive draining will reduce the pack's longevity.
Is this correct? And which is the way to go?