The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

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  • Generic Sony NP-FS11 Battery Packs: Surprising Contents Thereof

    So I dismantled the three junk packs I got from halfway around the world and rebuilt them with better-quality cells. Search for NP-FS11 and you’ll find the rest of the story.

    Some observations…

    These cases are the thinnest plastic that doesn’t actually break when you pick it up: to crack the case seam, you must push firmly. Two of the three packs were already cracked and the third yielded to a slight squeeze.

    What’s inside? Welly, welly, welly, what do we have here?

    DOA Battery Contents
    DOA Battery Contents

    The cells are labeled Sony Energytec, which ought to be a reputable brand name. Some possibilities:

    • Counterfeit cells
    • Quality test rejects

    I don’t know why you’d bother putting counterfeit cells inside a generic case; it’d be more profitable to sell a completely counterfeit battery with a fancy Sony label. So I’m guessing these came from a batch of cells that failed inspection and were miraculously saved from destruction.

    Battery Protection Circuit Board
    Battery Protection Circuit Board

    They have the usual protection circuit board on the top. What’s a bit tricky is that you must unsolder the three leads connecting to the case terminals before you can extract the cells. I unsoldered the strap from the negative terminal while I was at it; the positive lead is inaccessible beyond the black IC on the left.

    After that, it’s a straightforward rebuild.