Since I bought my Librettos for $15-$20/ea, I didn’t want to spend $40 on a rebuilt battery so I decided to have my friend James help rebuild a couple of the packs I have.

I have a 2 x 6-cell packs and 1 x 3-cell pack.  I purchased 9 “new” “Sony” 17670’s off of eBay.  I say new in quotes because they were not new when they arrived.  They obviously had been welded previously and someone ground the solder tabs off of them.  Also, we tested all 9 of the cells before we soldered up the pack.  Out of the 9, we found 3 of them at .66-1.30 volts.  When a Lithium Ion cell gets discharged to that point, you can kiss it goodbye.  It’s no longer viable because the chemistry changes and becomes less stable.  Another 3 were in the 2v ranges which may have been recoverable but probably not worth screwing with since it’s still outside of the specified operating range.  The final 3 were in the 3v range which was ok.  4.2v would be fully charged and none of them were anywhere near that.  Not that I’d expect them to be.

I say Sony in quotes because the batteries were counterfeit.  We could tell this because the physical structure of the cells are all slightly different and mismatched.  The blue jackets are printed at a very low quality level and are wrinkled in places where they’ve been improperly shrunk.

Counterfeit batteries are a HUGE problem on eBay.  I firmly believe that probably over 85% of the Lithium Ion batteries on eBay are counterfeit or of inferior/dangerous quality.  Most of them are extremely overrated as well.  For instance, a 18650 cell simply cannot hold 4000MaH.  It’s not physically possible for on of these cells output that much energy without draining it to an unusable state.

Whatever the case, our theory is that we are sending out batteries over to China to be recycled and they are disassembling the battery packs and reshrinkwrapping them and then selling them back to us on eBay.  Not sure if that’s the case with all of it but I’m sure that some of that is happening.

In the picture above, you can see very clearly the example of the wrinkled jackets.  Also, notice the real Sony cells on the right have different/darker colored jackets.

We finished the 3-cell battery up anyways with the 3 half-decent cells we picked from the batch.  I tossed it in my fancy outboard charger that came with one of the laptops and so far so good.  No heat and no smoke.  Time will tell if the rebuild was even worth the trouble.

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