A123 20AHr Pouch Cell Battery Build & Info Thread

[arkmundi]

arkmundi,
but you did not buy pouches from buya123, did you?
I cannot find any of your experience with buya123 pouch cells in this subforum.
You bought round cells, right?

26650 cells from buya123 and AMP20's from OSNPower

[miro13car]

it is obvious to me characters: A0, A1, B0, B1 printed in the middle , near the middle of A123 pouch means grading.
On some cells it is a0, b0 - small letters.
By grading I mean AHs delivered during discharge tests
I got cells with such characters and testing them on CBA confirms they indicate grading.
All cells marked B always delivered less than 19Ah on my tests.
all cells marked A or a always delivered just above 19Ah or well above 19Ah.
I tested on CBA in identical condition, cells charged to the same voltage by single cell charger.

[999zip999]

Mico13car I hope you broke the code. But can't wb9k chime in to back you up.

[docnjoj]

I'm sure he wishes he could, but his job would be on the line. Spouting trade secrets is never good for employment, unless it is to your competitor.
otherDoc

[999zip999]

Bump.
Tomjaz here is a thread with great info.

[whatever]

Just going back to page 37 of this thread. Wb9k stated that the separator membrane between the copper/aluminium sheets did not hold the electrolyte

The separator does not "hold" the electrolyte

That statement always puzzled me. If the separator didn't hold the electrolyte when you compress the cells, all the electrolyte would move away to the edges, unless it was absorbed by the porous membrane in some way.
Anyhow came across a paper that studied the effects of absorption of lithium electrolytes into the separator membranes. Which makes much more sense, it appears the separator membranes do absorb the electrolytes.
see
http://www.princeton.edu/~spikelab/papers/118.pdf

[whatever]

you can see also the a123 patent for separator membrane
http://www.google.com/patents/US8852787
which seems to suggest the electrolyte is held by the membrane

[Just2807]

I am really upset that an American company allegedly did this, especially one that got tons of government grant money to develop these cells over the years. If the allegations are correct, these million dollar a year executives should be stripped financially and be put behind bars...they knoweth what they dooith.

Well, every documentary or commercial or review or something about products from Germany is described as "proven", "reliable", "precise" or whatever, and when u ask anyone what exactly in detail.... They go "hmh?" It's a myth. U saw what happened few months back. They were doing something similar in 80's and 90' too, but that's another story. Poeple are forgetting pretty quick with todays media
Also, check out the funds American government is using on modern stealth fighter which is still faulty and will fly for sure in next 3-12 years (lol at this).

There are zillion examples but this is not the time or the place

Don't make this about nationality, people(!) are doing it, not nations. Greetings from Croatia, beautiful country where u vote for ex/future convicts in order to have better future.

Also, i am busting my balls on choosing how to parent my soon (i hope) upcoming lifepo 16s or 20s pack!
Thx alot for sharing your good and bad experiences!

[Doctorbass]

new update info regarding the A123 20Ah

https://www.buya123products.com/uploads ... 4db60a.pdf

They mention what i always believed about compression of the cells:

see at page 32:


Doc

[999zip999]

Wow I could download it and it was very interesting most times my phone can't download as PDF files. Very intense papers.
I mega wrap two 12s for a 24s pack to be used with 40 controller and now a new Sinewave 80amp controller 796 cycles vicpower group buy. Lucky I just.
Did test a month ago 1346wh 18.2ah with 46amp controller muxus 3,000 5t lots of hills always WOT.

[999zip999]

800 cycles 7317 total ah 11,245 miles.
About 4 years old 24s as two 12s just been bulk charging lately at 42v 16amp each 12s pack. Balances to 0.039 no bms. 139 amp max draw on C.A.
40amp draw most of life, now 80amp. More sag at 80amp.

[999zip999]

Ok 1,485 cycles a one cell went down cell #4 . I think there is more life in it and would like to keep it together. But need one cell .I'm calling out for one cell. If from 2012 and has 3.0v or so. Please help.

Just need one cell .

[999zip999]

I found two sellers on eBay one in L.A. and one in San Diego. 51usd and 50usd free shipping. If in the states should be legit ? So faster and ?

[999zip999]

Ok got my cell from San Diego. Till I looked at the cell after I punch some holes in it to bolt together. I fine there's a little Ray road track just above the pouch on the bottom of the tab next to the pouch where they have re-welded it together with some special welding device. The cell only charges to 3.36v Even after 2 hours at 5amps would not charge higher. I wish I would have fully charged and tested before I got the holes puncher. 3 hour later. Now I got to send it back and I looked at the eBay photo and he hates to have the same railroad tracks of spot welding on the cell he showed. Anybody have one cell that they would like to sell ?

[999zip999]

Ok new idea I could just go 22s or it's will be spilt two 11s. It's now two 12s.sib packs.
As two 11s packs can I do 1-6 with the sense wires then just pull the last wire on the second 6s balance to make it a 5s but in a 6s jst connector . And use my cellog 8s and my una9+plus charger thru the balance wires for balancing. No BMS. So 24s to 22s ? And bulk charge As 11s 38.5v or total 77v. My new plan.