Category Archives: Battery Rebuilding

Update to battery discharger Arduino code

Posted on January 7, 2011 by Jim

Added test for per-cell voltage < 0.95V (not configurable).  Aborts loop thru cells when one cell is done.  Prints message with capacity, guilty cell (though it’s obvious from the aborted line.)  I left the old overall battery voltage check in … Continue reading →

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The welder welds!

Posted on January 6, 2011 by Jim

I’ve connected/assembled enough stuff to actually test the first version of the battery tab welder.  And it works!  It’s certainly not in final form, but it very clearly functions as intended, and the welds test good! There’s really nothing to … Continue reading →

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Arduino code for discharger updated

Posted on December 12, 2010 by Jim

I tweaked the Arduino code a little more.  Deleted some debug leftovers, added some comments and restructured a subroutine.  I did a couple of several-minute tests with 1 and 15 cells to compute some timing fudge factors so the time … Continue reading →

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Discharger pictures

Posted on December 7, 2010 by Jim

I found my camera 🙂 . It hurt, but I clipped off the daughterboard (and removed the cut off pins).  There were a LOT of modifications to the board before it was done, but it seems to all work and … Continue reading →

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It works!

Posted on December 4, 2010 by Jim

The good news is the discharge board and initial software work!  Here’s a discharge of a 14 cell test battery: Battery Discharger version 0.90 Enter number of cells 1-15: Running test with 14 cells. Test ends at 13.30 volts. Press … Continue reading →

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New cap for tab welder

Posted on December 1, 2010 by Jim

The new “Volfenhag” capacitor for the battery tab welder arrived.   Here is it with the old crummy red Pyramid “1.5F” cap.  Doing a discharge test with a resistor, voltmeter and a stopwatch to find RC, it measured at 1.2F.  Not … Continue reading →

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It’s a shield!

Posted on December 1, 2010 by Jim

The battery discharge tester hardware is essentially complete.   You can see the 15 clip leads that go to the cell connections plus the red/black heavy clips that go to the very top and bottom to carry the discharge current. The … Continue reading →

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Eeprom test

Posted on December 1, 2010 by Jim

My order of ten 64Kbyte 24C512 I2C eeprom chips from China arrived.  They’re SOIC (small outline IC) rather than the more traditional 0.1″x0.3″ DIP package, and the part number on the chip was unrelated to 24C512 and I couldn’t find … Continue reading →

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Is good enough good enough?

Posted on November 24, 2010 by Jim

OK – I screwed up.  I missed implementing 2 features in the original board design, and now I’m paying for it trying to figure out how to hack the boards into doing what I need. The first missing feature was … Continue reading →

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New cap on its way for battery tab welder!

Posted on November 22, 2010 by Jim

The capacitive discharge battery tab welder (inspired by various web postings including ledhacks and the seminal philpem note) has been sort of on hold since I discovered the nominally 1.5F cap I bought measured at 0.3F.  I had even made … Continue reading →

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