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Wolf's PowIRwall
#11
A mentioned above here is the picture of the cell that had the rust hidden under the insulator.
I am now re-wrapping all my cells.




Wolf
If 18 X 650 = 2200+mAh then we have power! 
May all your Cells have an IR of 75mΩ or less Smile
Last count as of 01/23/2020
Total Number of Cells Recorded and processed                 6263
Total Cells required for PowIRwall  14S80P+1                  1200
Total Cells ≥2200mAh, ≥80%, ≥35mΩ, ≤75mΩ, ≥4.12V   3286
For Info Google Drive
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#12
Update on 2 things.
# 1 I found another rusted cell that looked perfect on the outside had good readings as far as mAh, V and IR.

Sorry the picture is a little fuzzy but was trying to get as good as a closeup as I could.


#2 After watching HBpowerwalls youtube video https://www.youtube.com/watch?v=7rd4tDJ6eKs on rewrapping cells I gave it a shot.
Just a couple of changes.
I put the magnet on the cell first and slide it to the center then I put the cells on the back of a baking tin

 

Push the wrap down till it touches the tin then very carefully use the heat gun on low fan, high heat setting and point it straight down onto the top of the cell. slowly getting closer till the wrap closes over the insulator. You may still get an occasional insulator flyoff but much less than if you attack them from the side. Once the top of the cell is done you are in the clear.
The rest is easy and you will have perfect results every time. Takes the guesswork of the alignment of the wrap. Thanks for a brilliant method hbpowerwall!!


 10 more packs to go Big Grin

Wolf
If 18 X 650 = 2200+mAh then we have power! 
May all your Cells have an IR of 75mΩ or less Smile
Last count as of 01/23/2020
Total Number of Cells Recorded and processed                 6263
Total Cells required for PowIRwall  14S80P+1                  1200
Total Cells ≥2200mAh, ≥80%, ≥35mΩ, ≤75mΩ, ≥4.12V   3286
For Info Google Drive
Not your average Wolf       
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#13
Those bastard insulators always time it just right, flying off as the wrapper starts to shrink!
Perhaps some sort of weight, or shrink wrapped magnet can hold it in place?
OffGridInTheCity and Wolf like this post
Modular PowerShelf using 3D printed packs.  50kWh and growing.
https://secondlifestorage.com/showthread.php?tid=6458
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#14
Update:

So after Spot Welding the 5p Fuse sheets from Battery Hookup  (I really hope they get some more of theses sheets soon) I encountered a dilemma.
How was I going to get the power from the batteries to a connector safely and mechanically sound.
I couldn't just solder a big wire to the sheet somewhere and call it good.
Besides taking a mΩ reading of the sheet which is 12.5 inches  from end to end is ~ 5mΩ. enough to cause a small voltage drop.
So onto busbar design and planning

  

I spent a bunch of time looking at all kinds of busbar designs and sketched a bunch of them out and finally decided to go with my design #5.
The sides will be covered with Lexan to protect the cells and the wiring.


To bring it to reality I spun up some  AWG #8 solid copper wire with a drill to straighten it did some bending attached a 1/16 X 1/2 copper bus bar with solder and this is what the prototype looks like. It will be soldered to the fuse sheet every 3 or 4 inches. From the busbar I will use a marine tinned copper wire lugs AWG #6 1/4 Ring complimented with marine AWG #6 tinned cable, terminated with  Anderson PP75 Connectors.



Now to build a jig so I can mass produce 29 more of them for now.

Wolf
If 18 X 650 = 2200+mAh then we have power! 
May all your Cells have an IR of 75mΩ or less Smile
Last count as of 01/23/2020
Total Number of Cells Recorded and processed                 6263
Total Cells required for PowIRwall  14S80P+1                  1200
Total Cells ≥2200mAh, ≥80%, ≥35mΩ, ≤75mΩ, ≥4.12V   3286
For Info Google Drive
Not your average Wolf       
            Cool
Reply
#15
(03-30-2020, 12:50 PM)ajw22 Wrote: Those bastard insulators always time it just right, flying off as the wrapper starts to shrink!
Perhaps some sort of weight, or shrink wrapped magnet can hold it in place?
Yes sir - you've got to blow upwards 'just right' till the edge traps the insulator - burning your fingers sometimes Smile
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#16
I have found with the magnets and the baking pan trick if you hold the heat gun straight above the cell at about 6 inches with high heat (setting 4 on the Wagner Furno 500) and low fan (default setting) you can eliminate the insulator fly off almost to 100%. Patience is the key and slow movement of the heat gun. Additional benefit fingers and hands need not be used and no burns Smile


Again once the top closes you are in the clear.
This batch was done without a single fly off Big Grin

 

Wolf
If 18 X 650 = 2200+mAh then we have power! 
May all your Cells have an IR of 75mΩ or less Smile
Last count as of 01/23/2020
Total Number of Cells Recorded and processed                 6263
Total Cells required for PowIRwall  14S80P+1                  1200
Total Cells ≥2200mAh, ≥80%, ≥35mΩ, ≤75mΩ, ≥4.12V   3286
For Info Google Drive
Not your average Wolf       
            Cool
Reply


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