[Tfug] Source for notebook batteries?

[Bexley Hall]

Hi Jim,

> Bexley, I understand perfectly that the total voltage must
> remain the same, therefore you need to play with the whole
> series/parallel thing.
> 
> And yet again, we agree that it's safer to up the mAh
> rating for each cell (doing all at once of course!) than to 
> up the number of cells.
> 
> Where we disagree is on cost :).  Some of these cells
> are only six bucks a pop.  Even times six plus shipping plus some
> solder, we're WAY way under the price of a new pack.

You'll need to see just what's inside your battery pack.
You might have one string of six cells, another string of *four*,
etc.  So, its hard to guesstimate what the total number of
cells in the pack is a priori.

You can't solder directly to the cells.  One, you risk
fire/explosion.  Two, many have stainless steel, etc.
cases that just don't *take* solder.  :<

So, you have to buy the cells with "tabs" pre-welded onto them.
Depending on the size of your battery *pack*, (i.e., how much
spare room there is inside) you might find it difficult to
buy N "single cells" and solder them together yourself as
eash junction made this way will be a bit larger than
you'd imagine  :>

When the batteries are made at the "factory", each of these
tabs is welded to the adjacent cell/cells (again, some packs
might have several strings inside) so they take almost
no room (they are flat pieces of metal that conform to
the shape of the cells themselves).

So, for a DIY approach, your time needs to be relatively
cheap.  Going to a place that makes battery packs you will
find yourself paying for *their* time (and usually not saving
much).

Note, also, with Li Ion batteries, you really want to be sure
of your supplier.  Any impurities in the batteries formulation
can lead to "spectacular" results down the road :>