Hopefully the pack won't get hot enough to cook the pierogies.
Yes I hear you on this one. The thing that is interesting is that Eric has spoken with the chinese vendor and the impression that he got was that they were prepared to supply large quantities of these cells and were talking of quantities / month, as though there was no limit?
I visually checked all of the 152 cells I have, and sure there are some wrinkles and small blemishes, but overall, they look pretty good.
I hope to take a ride to the level gauging company that I built the production line for, and try some HYPot testing of the pouch to tabs. I will take an assortment of cells with different blemishes, and use the aluminum plates as the outer connection. If I can get to over 1KV, I would think we are ok.
From the inspection so far, and the HV tesla coil testing the foil pouch seems to be electrically isolated from the inner parts. It sounds like a weld in the inner cell had sharp edges and was able to puncture that inner insulation, which would make the foil of that pouch be at the potential of the cell in the stack relative to the other cells. The foil pouch also has a heavy plastic layer over it, so only the edge and bottom of the pouch where the foil is exposed would be electrically hot, so I will also do a hypot test from the foil to the terminals.
All speculation, but knowing how these recalls go, I expect that as soon as they found the problem, they pulled all the stock and since it is a mechanical issue, and the punctures are inside, they probably just trashed them all instead of taking the chance, and that's where the Chinese vendor seems to have started selling the cells.
I have not had much luck getting information from A123 in the past, but getting a reading on the serial numbers it is probably something worth pursuing.
Eric, you have the range of serial numbers you purchaced, may be worth a phone call to A123 to see how far you get.
May also be worth asking about the availability and price of new cells directly from them as a comparison?
Last edited by Mike Dabrowski 2000; 07-06-2012 at 09:20 AM.