3s1p pack reconfiguration  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       



All Forums >> Radios, Batteries, Clubhouse and more >> Batteries & Chargers >> A123Racing Support >> 3s1p pack reconfiguration
Page: [1]

Login
Message << Older Topic   Newer Topic >>
3s1p pack reconfiguration - 1/8/2007 4:19:11 PM   
jaofos


 

Posts: 204
Joined: 10/1/2006
From: , TN, USA
Status: offline 		Just curious if anybody here has dissected one of the 3s1p retail packs and re-arranged the cells in a different configuration. Depending on how the cells are connected I don't see it being a terribly difficult task.

The reason I want to do this is I only run the packs in my stampede with an FLM extended chassis and I'm wanting to fab an under-chassis battery mount, but the height of the pyramid pack configuration makes this extremely difficult. It would be much easier to make a flat lower deck if the cells are in a side-by-side configuration.

Brian, maybe you can chime in here. How difficult would it be to unwrap the cells and re-arrange them? I know the dev cells come with the tabs but I'm not sure what is hiding under the wrapping of the retail packs.

Thanks,

Steve
       Post #: 1

RE: 3s1p pack reconfiguration - 1/8/2007 4:59:05 PM   
A123 Racing


 

Posts: 101
Joined: 8/25/2006
From: Hopkinton, MA, USA
Status: offline 		Hey Steve,

It would be somewhat difficult to re-assemble a 3S1P pack into a flat pack because of the way it is built. It would be much easier to buy a developer kit and solder your flat pack together yourself with a little heat shrink to finish it off nicely.

Let me know if you have any more questions.

Brian



(in reply to jaofos)
       Post #: 2

RE: 3s1p pack reconfiguration - 1/8/2007 5:22:01 PM   
jaofos


 

Posts: 204
Joined: 10/1/2006
From: , TN, USA
Status: offline 		Somewhat difficult is better than "impossible"

Can you give me a hint as to whats hiding under the wrapping of my 3s1p packs? How are the cells connected together? Are there tabs? Would I just melt the solder off, re-arrange and re-solder them?

Thanks!

(in reply to A123 Racing)
       Post #: 3

RE: 3s1p pack reconfiguration - 1/8/2007 11:54:54 PM   
jaofos


 

Posts: 204
Joined: 10/1/2006
From: , TN, USA
Status: offline 		What exactly does twisting the cap the tabs are welded to do to the cell?

(in reply to jaofos)
       Post #: 4

RE: 3s1p pack reconfiguration - 1/9/2007 12:34:05 AM   
everydayflyer



Posts: 860
Joined: 8/21/2005
From: Buchanan, GA, USA
Status: offline 		Destroys the seal and can cuase the cell to go open.. Photos are not mine and I would gladly give credit if I could remember the source.

Attachments
Click to see fullsize image.
Click for fullsize


< Message edited by everydayflyer -- 1/9/2007 12:37:13 AM >

(in reply to jaofos)
       Post #: 5

RE: 3s1p pack reconfiguration - 1/9/2007 12:54:45 AM   
jaofos


 

Posts: 204
Joined: 10/1/2006
From: , TN, USA
Status: offline 		Well I figured to get the configuration I wanted I would probably have to buy new cells, so I unwrapped the cells to take a peek and to flatten the pack out I just twisted one cell 1/3 a turn and then taped them back up in a flat configuration.

Nothing popped off and the battery ran fine for the two cycles I was able to test tonight. I won't be doing my other that way, since I have a feeling I got lucky not destroying mine.

I'll just wait and get some dev cells I guess.

(in reply to everydayflyer)
       Post #: 6

RE: 3s1p pack reconfiguration - 1/9/2007 1:00:40 PM   
klhoard



Posts: 528
Joined: 9/4/2002
From: Collierville, TN, USA
Status: offline 		.
.
.
Do you guys know that Tanic sells A123 packs now?
.
.
.
Brian will solder them up however you want them. www.tanicpacks.com
.
.
.


_____________________________

Keith Hoard
Collierville, TN

(in reply to jaofos)
       Post #: 7

RE: 3s1p pack reconfiguration - 1/9/2007 1:05:21 PM   
everydayflyer



Posts: 860
Joined: 8/21/2005
From: Buchanan, GA, USA
Status: offline 		I do but I am not going to pay $25per cell myself when my DeWalt cells cost me $10-$11 per cell. Let's see $35 for me to built a 3S from DeWalt cells or $75 for a premade. It takes me 15 minutes and I save $40.


Charles

(in reply to klhoard)
       Post #: 8

RE: 3s1p pack reconfiguration - 1/9/2007 9:34:01 PM   
dcheatwood


 

Posts: 3
Joined: 8/5/2003
From: Katy, TX, USA
Status: offline 		Hello Everydayflyer,
Please share info on how to go about doing this build from Dewalt cells or maybe a link to this info. Also which Dewalt power packs to purchase. I know that the packs have to be disassembled. The rest is knowledge that many of us could use.
Thanks Doug

_____________________________

Doug Cheatwood

(in reply to everydayflyer)
       Post #: 9

RE: 3s1p pack reconfiguration - 1/9/2007 11:33:41 PM   
everydayflyer



Posts: 860
Joined: 8/21/2005
From: Buchanan, GA, USA
Status: offline 		http://www.rcgroups.com/forums/showthread.php?t=599316

http://www.slkelectronics.com/DeWalt/packs.htm

Hope Brian does not get to upset with me. We think outside the box on RC Groups

Those interested in alternate A123 sources,packs,chargers,balancers relly should visit

http://www.rcgroups.com/batteries-and-chargers-129/

and do a Search on A123

There is a lot more going on over there.

Want to see a rather large A123 battey?


http://www.rcgroups.com/forums/showthread.php?t=623723

Charles

< Message edited by everydayflyer -- 1/9/2007 11:37:23 PM >

(in reply to dcheatwood)
       Post #: 10

RE: 3s1p pack reconfiguration - 1/10/2007 3:39:51 AM   
dcheatwood


 

Posts: 3
Joined: 8/5/2003
From: Katy, TX, USA
Status: offline 		Thanks for the info.
Doug

_____________________________

Doug Cheatwood

(in reply to everydayflyer)
       Post #: 11

RE: 3s1p pack reconfiguration - 1/10/2007 3:40:48 PM   
jaofos


 

Posts: 204
Joined: 10/1/2006
From: , TN, USA
Status: offline
quote:

ORIGINAL: everydayflyer

Destroys the seal and can cuase the cell to go open.. Photos are not mine and I would gladly give credit if I could remember the source.


Looking at that picture you posted, it seems like just turning what the tabs are welded to on the positive sites would just turn the rivet inside and not the whole cap that pops off.

Is that rivet sealed in some way that affects the cell? Just from looking at the pictures I can't see where turning that would damage the battery, as its just holding the little accordian connector to the cap.

(in reply to everydayflyer)
       Post #: 12

RE: 3s1p pack reconfiguration - 1/10/2007 4:59:24 PM   
everydayflyer



Posts: 860
Joined: 8/21/2005
From: Buchanan, GA, USA
Status: offline 		Well in the first place the cell is sealed I would think but perhaps not and twisting the end(s) can destroy the seal as I see it. Secondly the connectors from the cells matrix to the ends are not designed to be hinges.

Info sheet which comes with cells from A123 Racing.

"DO NOT rotate the negative tap (cap) relative to the can, this can cause internal damage to the cell"

Take it for what it's worth. They did not mention the positive cap nor did they mention damaging a seal.

(in reply to jaofos)
       Post #: 13

RE: 3s1p pack reconfiguration - 1/10/2007 5:22:37 PM   
jaofos


 

Posts: 204
Joined: 10/1/2006
From: , TN, USA
Status: offline 		Well as soon as the weather wants to cooperate, I'm gonna put few more cycles through the pack I altered and see how it holds up. From the picture you posted I can't see where twisting that small cap on the positive side could damage the cell.

Need to fastforward to summer time again so it's not pitch black dark when I get home from work at 5:30pm, and if it would stop raining every single weekend this winter I could really start to enjoy these packs

(in reply to everydayflyer)
       Post #: 14

RE: 3s1p pack reconfiguration - 1/10/2007 5:37:04 PM   
everydayflyer



Posts: 860
Joined: 8/21/2005
From: Buchanan, GA, USA
Status: offline 		Perjhaps Brian will clear this up but .

The Positive end is the one which has what appears to be a gragile metal strip which when twisted could shear.

The negative end is the one with the folded braid material. The negative end has a blue bot in the center of ther vcap which is where the cell is sealed after assembley with UV activited sealeant.

It would seem to me to be a very bad idea to twist either end cap and risk damaging the seal.

93 cycles and still kicking Mule.

Charles

(in reply to jaofos)
       Post #: 15

RE: 3s1p pack reconfiguration - 1/10/2007 5:42:33 PM   
jaofos


 

Posts: 204
Joined: 10/1/2006
From: , TN, USA
Status: offline 		OK, I got the ends confused then. I thought the positive end was the one with the blue dot and the rivet I'm talking about.

The smaller cap on the negative end is the only thing that turns when you twist it, and it looks like it's twisting on whatever holds that small cap to the end, which inside the cell holds the braid material, which should stay in place. I wouldn't think that turning the small cap would break the seal as it's inside the rivet, nor damage the braid inside.

But hey, if A123 says not to.. there's gotta be a reason.

(in reply to everydayflyer)