Midwest a123 group buy

Talk about anything and everything here within reason.

Re: Midwest a123 group buy

Postby deVries » Wed Apr 18, 2012 9:19 pm

johnrobholmes wrote:I really don't have any good answers on the supply chain, besides what I have already posted here. Methods has also bought cells from Victpower, all his findings are in his thread. This are bigger and heavier than hobby city type packs, but there are less connections and they are CHEAP! I have never used the cells, but I fully intend to! There are some people working on building solutions for the cells on ES, search the forums and see who is doing what. I'm half tempted to make some crude bar clamps and be done with it, I won't pull more than 80a from the pack.


I bet what happened (me just guessing) was that the cells were destined for pack building, then the whole GM bailout happened. a123 probably got a cut of the bailout for the product that was already made, and the homeless cells got sold through factory contacts back into china. Now they are absorbing the cells into their own supply chain and there are cottage industry businesses picking up on the grey market need for cells elsewhere in the world. A grade? B grade? How will we know until years down the road? Doesn't matter and i don't care, I'm willing to take a gamble that I can get a year of use at 4c bursts and 1c average rate.

Thanks! :D for sharing the details of what you know. If these turn out ok, then do you intend to probably do another group buy? :?:

I see BigMoose has started a thread about these cells here, click link below, so this will be a good thread to follow-up on pack building experiences & testing results.

A123 20AHr Pouch Cell Battery Build & Info Thread
deVries
1 MW
1 MW
 
Posts: 1652
Joined: Thu Jul 10, 2008 11:29 pm
Location: Solar Powered 3000w Austin Texas

Re: Midwest a123 group buy

Postby johnrobholmes » Wed Apr 18, 2012 9:20 pm

I may do another group buy, but I will have to pad enough time to pay myself on future buys as I won't be getting any for myself. I will have about 5 hours in the unpacking, testing, repacking of this little lot.
_______________________
Image

Volt up, gear down!
http://www.HolmesBikes.com -- Custom 15 -12ga spokes
http://www.VoltRiders.com -- Custom wheels, ebikes, and Mopeds
User avatar
johnrobholmes
10 GW
10 GW
 
Posts: 4139
Joined: Mon Jul 07, 2008 2:19 pm
Location: Missouri

Re: Midwest a123 group buy

Postby bigmoose » Mon Apr 23, 2012 5:46 pm

John's cells arrived today! All in superb shape IMHO. John did a great job packaging and shipping them. I can only imagine the time it took. I know how long it took me to just unwrap, measure and photograph, rewrap and store them.

All cells measured either 3.292 or 3.293 Volts on a well calibrated DVM. No tearing or crushing of the foil packets. One thing that I didn't expect was the foils on the long edges were shaped and curled into a "C" along the long edge. They were not flat like the cells I had seen photos of before. The white plastic packaging fit the cells once curled into the "C" shape, so it appears deliberate and helps in shipping I believe. The part of the cell that takes the most "hurt" is the area between the tabs where the shaped shipping liner contacts the foil.

Center stampings were either A0, A1 or A2

First line on all was APP72161227 followed by blank, P1, P2 or P3. This varying mark did not correlate with A0, A1 or A2 markings.

What appears to be serial numbers or date codes varied:
SH(A,B,C,or D)11(A,B,D, E,F )xxxxxxx followed by blank or P1 P2 or P3

All said on the last line
300386-USA

Two things I noticed on two cells. After unwrapping and feeling the cells you hand gets a feeling for what is the norm, sort of like feeling currency. Let me show you one cell that had a texture anomaly. I wonder if this is the "shift" or misalignment that A123 talks about? It is on the cell that I labeled "3" a P1 cell SHA11E0400339 There was a slight ridge down the middle of the cell. About 5/8 inch wide and raised on the front and back by say 0.012 inches. The "thing" under the foil seemed to have sharp edges. Pix below are the cell, my finger points to the ridge on the front and the back.
Cell3.jpg
Cell3.jpg (49.03 KiB) Viewed 244 times

Cell3FrontFold.jpg
Cell3FrontFold.jpg (49.01 KiB) Viewed 244 times

Here I marked where it feels like there is an extra "tape" inside the foil package. It is both front and rear, and just about right down the middle.
Cell3FrontFold2.jpg
Cell3FrontFold2.jpg (54.93 KiB) Viewed 239 times

Cell3BackFold.jpg
Cell3BackFold.jpg (43.85 KiB) Viewed 244 times


EDIT: I have been thinking about this ridge. If I were to package this cell I would use my 0.010 in thick fishpaper and make it two layers thick. I would remove the second layer in the center, say a 1 inch wide piece to take the pressure off of that ridge. I could very easily see how if this cell was stacked with the others and compressed, all the pressure would be on that ridge. If I basically make a spacer and put the pressure on the sides of the cell and not on the ridge, I might be OK.

Then towards the bottom of the stack my cell "17" that caught my eye because it was the only one with no "P" number after the APP72161227 line. Then I looked closer and all the writing looked squished together and was blacker than all the other cells. The 17 other cells were very consistent in marking. Number 17 had the lines closer together and the line height was less for the printing that is on th body of the cell. I would say shrunk about 15% or so. However the line of printing that goes across the tabs looks identical on all cells.
Cell17Label.jpg
Cell17Label.jpg (54.41 KiB) Viewed 244 times

Cell 18 for comparison. This was the norm.
Cell18Label.jpg
Cell18Label.jpg (52.85 KiB) Viewed 244 times

I don't know really what to make of my observations. I would say 16 of the cells appear identical. One had the fold in the center, but it's markings were like the others. One cell looked and felt fine, but the markings were shrunk 15% and there was no P number on the first line.
bigMoose's electronic pieces & parts (GENUINE IRFB4110Pbf's, Nomex 410, AntiCorrosion Grease, Current Sensors) available HERE.
Thanks to Justin ebikes.ca for securing the board then setting us FREE! Tech Tips in the WiKi: http://endless-sphere.com/w
"Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God..." all the best, Dave
User avatar
bigmoose
10 MW
10 MW
 
Posts: 2451
Joined: Thu Aug 06, 2009 3:05 pm
Location: Northern Ohio, USA

Re: Midwest a123 group buy

Postby johnrobholmes » Mon Apr 23, 2012 6:03 pm

Good observations there. I'll look through what I have here and see if others have a defined ridge on them.
_______________________
Image

Volt up, gear down!
http://www.HolmesBikes.com -- Custom 15 -12ga spokes
http://www.VoltRiders.com -- Custom wheels, ebikes, and Mopeds
User avatar
johnrobholmes
10 GW
10 GW
 
Posts: 4139
Joined: Mon Jul 07, 2008 2:19 pm
Location: Missouri

Re: Midwest a123 group buy

Postby kevo » Tue Apr 24, 2012 8:32 pm

John, you are an ES hero. These group buys are tricky business, thank God for those who do it well :!:
Thanks Justin of http://ebikes.ca for your amazing talents, dedication and contributions to ES!
Post licensed under "Open Source" http://creativecommons.org/licenses/by-nc-nd/3.0/
kevo
1 kW
1 kW
 
Posts: 328
Joined: Tue Sep 15, 2009 9:40 pm

Re: Midwest a123 group buy

Postby 999zip999 » Fri Apr 27, 2012 10:00 pm

John tried to email but got a failure. The bill you sent me had zero 0 for shipping ? Is this right ?
999zip999
100 MW
100 MW
 
Posts: 2948
Joined: Sun Jan 10, 2010 1:40 pm
Location: Dana Point So. Cal

Re: Midwest a123 group buy

Postby ohzee » Sat Apr 28, 2012 12:47 am

Mine showed up today and looked great. Thanks a lot for your help with this group buy.
User avatar
ohzee
1 MW
1 MW
 
Posts: 1627
Joined: Wed Jul 20, 2011 1:13 pm
Location: Columbus Ohio USA

Re: Midwest a123 group buy

Postby deVries » Sat Apr 28, 2012 4:07 am

johnrobholmes wrote:Good observations there. I'll look through what I have here and see if others have a defined ridge on them.

Did you or anyone else find the center-line ridge or shrunken writing that BigMoose observed? :?: :?: :?:

Thanks BigMoose for documenting these "anomalies". :D It will be most interesting to uncover this mystery eventually... I'm sure someone will get to the bottom of it at some point hopefully sooner rather than later. 8)
deVries
1 MW
1 MW
 
Posts: 1652
Joined: Thu Jul 10, 2008 11:29 pm
Location: Solar Powered 3000w Austin Texas

Previous

Return to General Discussion

Who is online

Users browsing this forum: Chalo and 7 guests