I think I have finally lost it. That's it I have gone totally anal and I belive I need to be committed. Please help me out.
After all the talk of cells catching on fire and all that sort of stuff I am now more than ever committed to building the safest and most durable battery that is possible.
Anyone that has read my build thread knows how I go about testing cells and how meticulous I am as to what cells will pass my criteria and finally find a place in my powerwall. I'm sure you all are tired of this by now nevertheless I will reiterate for the first time readers.
My first process is logging all the cells info into a spreadsheet.
It has grown to this monstrosity of collecting as much data as I can. 29 data points and 1 for notes.
One thing I have found out is that you can never have too much information.
The spread sheet allows me to sort all the cells by specific parameters. To build my packs, I chose the highest initial voltage, the lowest post test IR, the lowest voltage drop after the >25 day SD test and of course capacity.
I then take those results format the data for Nemos Excel Repackr. Cell Number, mAh, and IR.
You see the great thing about Nemos Excel Repackr is that its results maintain the cell number making it easy to build your packs by cell number rather than trying to find the mAh of the cell.
You can then sort by cell number and it gives you the pack number the cell should go into.
Now here comes the crazy part after all the cells have been distributed into their corresponding packs I perform a last and final voltage and IR check. At this check I compare the present IR reading to the >25 day IR check and compare the voltage reading to the value of when the cell came out of the charger/tester. At this point if there is too much of a deviation the cell gets replaced with another. So far this has not been necessary as all the cells have been within stringent parameters,. During this process I actually sort the cells again and record the row and slot they go into. So you see I am going insane with my anality.
On the other hand if I ever have a mishap with one of my batteries I at least will know after forensic analysis which cell and what number may have caused the issue. Nuts right?
Alright on a more sane note Battery #2 is almost ready to install into the Battery Box. The Lexan sides have been installed and the Logmons have been placed less 1 which still has to have the holders glued on. I also ran out of nylon nuts and washers which have been ordered. My math was off by 6 or I misplaced them.
Some pictures of the process.
Of course the Lexan sides have been cut, edges rounded, holes and access relief drilled.
Small 1/16 holes drilled into the cell holders to accommodate the #4 x 5/8 screws to hold the logmons in place.
I am actually drilling into a void and it gets no where near the cell for those that would be worried.
Battery #3 (the gray cells) is underneath and I have just finished pac #7 with spot welding the fuse sheet. I do love the Kweld it is just so predictable and consistent.
That's it for now more to come soon.
So should I be committed? If so please don't tell them where I live.
Wolf
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