[Thinkpad] Re:Battery Refill

Two items:
1) I've bought Li-Ion replacements for my two 600e's from Kahlon. Last invoice from them dated 04/2003 was $106.00 plus ship.
Still working fine and one pack is going on 2+ years.

2) I work with LI cells on a daily basis and they exhibit no better or worse characteristics than NiMh when stored, and definitely store better than NiCads. By better I mean out of the perhaps 80 cells I rotate, cycle, catalog and re-use, I'll get a cell that won't hold a charge or has an internal short and won't charge at all. This is why when you deal with multi-cell packs like the type the 600e uses, all it takes is one marginal cell out of the six to bring down the whole pack. This is what happens usually when the packs have a rapid voltage drop over time.
So to say good, usable packs stored on a shelf for years would be just as good as a fresh pack is not realistic. If you're lucky, yes, if not, you wasted money and time. My equipment I make a living with uses packs of indiv. cells in an array that doesn't require soldering so I can keep track of the strong cells and discard the marginal ones (at some expense I might ad).
I've opened the old 600e packs and taken out the 6 Li-Ion cells to cycle and measure the internal resistance. Both times I've found a cell with marked non-linear discharge rates. ( I use the same Panasonic cells at work and no, I won't waste the time to spot weld them in the old packs for the 600e.)
My point is, the battery pack micro-controller may be a "Big Blue" bad-mojo device, which I doubt, you are still at the mercy of one cell out of six showing a defect and drawing down the whole pack. Unless you have time to waste, you are better off buying a new (relatively) pack than a used, stored on the shelf for who knows how long pack. Unless it is free.
My two cents.
John
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Received on Tue Mar 2 16:48:03 2004