In article , mike wrote:

| You MUST have a spot welder to connect the cells. DON'T LET ANYBODY
| TELL YOU OTHERWISE!!!!!

Here, I'm going to tell you otherwise.

Sure, it would be nice -- it would make the job a lot quicker, which
would be important if you wanted to make a business out of it.

But you can certainly solder your own battery packs together, and once
you get the hang of it, the odds of a bad pack are very low.

The key is to have a hot soldering iron -- 80 watts or so -- and to be
very quick -- no more than 3 seconds of heat on the battery. More,
and you risk damaging the cell. Typically I glue the cells together,
use a dremel on the tips to make them rough and to clean them up, tin
them with solder ( 3 seconds each), then use desoldering braid to
solder the cells togeter (again, 3 seconds each.) Once done, I
throw it on the battery cycler and make sure that the pack's
performance is what it's supposed to be. If not, I throw the pack
into the `recycle it' bag.

I've made lots of them -- for radios, for R/C planes and transmitters,
for power tools, and have not had any problems beyond a small
percentage (10% ?) not making the grade once I ran them on the cycler.

If you're afraid of soldering directly to the battery itself, you can
buy cells with soldering tabs, but I find it's easier to do it without
them, and you'll pay extra for those cells (certainly, you won't find
them on sale at Frys or Harbor Freight Tools for under $1/cell for AA
cells.)

| You MUST have a LOT of insurance. If anything you ever touched
| catches fire or if someone's laptop dies for ANY reason, you'll
| be getting a call from some nice lawyers.

Probably true. I certainly wouldn't rebuild somebody else's laptop
battery for them, but I might try it for my self.

| You MUST have proprietary information from the equipment vendor.

This will depend on what you're doing. Certainly, most NiCd/NiMH
packs use AA, AAA or subC cells and there's nothing special you need
to know there. But for the LiIon and Lipo packs, there may be
something special you should know. (And abusing these packs can cause
fires -- very bad.)

I know you mentioned LiIon cells specifically, but if you were to get
into the business, I suspect you'd be doing NiCd and NiMH batteries
too ..

| Some/many battery packs lose their brain when you disconnect the cells.

I've never run into that problem, though I don't doubt it exists.
I've even rebuilt some LiIon packs with good results, removing the
circuitry on the pack and putting it on a similar LiPoly cell. It's
not really pretty, but works well. The LiPoly cells I've bought had
solder tabs, which was nice.

| Nobody is ever happy with their device battery. Last place you
| want to be is in the middle. "Battery pack can't be repaired."
| "Whaddya mean, it worked when I sent it to you?".....
|
| Suggest you find a simpler business with less legal downside and fewer
| customer issues.

Probably good advice. But for your own use, rebuilding packs is a
great way to save money.

--
Doug McLaren,
Things just haven't been the same since that house fell on my sister ...