CRUD's Powerwall Project

daromer

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Time to get to work then :)

Yeah twisted busbars is so simple and you generally can get those wires for free in electronics scrap :) They throw away many small pieces.
 

crud

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Apr 5, 2017
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So yesterday i tried a new battery pack configuration.

I started this thread with the idea of a maintainable pack, but i realized that the effort to create all the features in mind would get time consuming and rather expensive due to the materials and processes.

Finally i go with this solution:

Following other successful attempts, i'll go with the twisted busbars (3x1.5mm2 wires twisted) on both positive and negative (following others and well imagined bythe original tesla patent idea ->https://www.google.de/patents/US767...ved=0ahUKEwjHh6SZjf3UAhWL7xQKHXpgA9kQ6AEIJDAA).

To make the pack more maintainable (as cells and busbar do overlap due to the battery holders design) i added more space, which makes the packs bigger (but i don't mind):


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So the busbar sits on some extra holders.


As seen in the very left holders column, i removed the holding edges (by example).

All edges on the top will be removed so the cells can be removed if needed. The extra holders (where the busbar sits on) will be connected by 18mm bars -> to be continued ...
 

daromer

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1m2 is quite large. I doubt you get any voltage drop :D

Note that you do not need to put the bar in middle for being able to pull out eventuall cells... I got 3*2.5mm2 and i can do it:

 

crud

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Apr 5, 2017
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;-)
Yes, thats big :) Just fixed that :)
Well i tried that but i decided to give it more space in advance. I also checked out your video in advance but i'd like to try out some configuration with ready slots (without breaking off the edges afterwards).
I admit that i might not get too much advantage over other configs. Its more kind of a design experiment.
 

daromer

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No need to break any corners in advance. If you take off the corners before some cells will glide back and forth very very easy and may cause issues to the fuse wire if you move em. Not a big deal but its easy to remove eventuall corners after :)
 

crud

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Apr 5, 2017
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So after some rethinking i guess i am getting closer to what i think could work (for me).


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Using the off the shelf battery holders, i made a fixation that will go 4 times into each pack to give the grid some inner stabilization.

The busbars will go on the plates of the holder construction.

Goal/Idea

1. While using the common holders, give the busbar more room so the cells can slide in and out more easily.
2. After having the grid set up, put more enforcements to make it a solid empty carrier for the cells and the have a reusable battery case.
3. Put some nice looking stuff on the sides (like in the initial 3d Design) -> Honestly, i don't really know whyi have this urgent desire to make the packs look nice ...


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crud

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Apr 5, 2017
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So finished the first container grid today.

1. Created 4 stands per pack (80p)
2. removed edges on the top - beware of sharp edges inside the holder - they have to be removed other wise the cells protective skin will be demaged
3. After cleaning, the cells slide in easily and are fixed with a nice clicking sound inside the holders.
4. Also used the cable holders technique to get the busbar additionally fixed above the stands.


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