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New easy lithium battery boxing system, can build 1KW of 18650 in 20minutes

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Hi there! I'm hoping for high quality feedback for this topic, so if you don't know very much about contractor alloys and have never worked with pressure contact design, unless you can state some industry materials related to the project, then that's not the kind of intel. i'm interested in!

It's an incredibly technical project, focusing on a small number of pieces, to tweak them for absolute maximum performance and safety, robustness, easy of use, so a lot cool tweaks will happen prior to the final version.

I'm aiming for a box cost of $30/KWh of cells for home-made versions, to $70/KWh if you glue the factory kit yourself.

It can be completely air-tight, for humidity and splashes, using 50 PSI rubber seals and a 15 PSI pressure equalization valve and color changing silica gel, for those that live in jungles as dry as a shower cubicles.

It's going to be open-source. Everyone can 3D print boxes components of and every every size enclosure using the box STL generator...

Other companies can make make their versions, I'll try and subsidize solar for DIY'ers from the Phillipines, Cambodia, Bolivia, faraway places.

Maximum electrical output is 100A for the big box from the video, when it's configured to 12V, and only 50A @ 24V.

The springs are not electrical, the current goes through 8AWG Copper busbars and 20mm2 Aluminium-Nickel contacts compressed by 2KG force springs.

My problems with it ... lack of spot welding / soldering. You're adding a lot of wire resistance with the springs, and you're adding contact resistance not to mention the issues of humidity getting in and potentially having corrosion on the contacts.
Then you're having those locking screws through the lid, so there's another potential for water / humidity to infiltrate along the shaft of those screws and get the battery wet inside. Have a look at how multimeters and other devices have a double wall or a depression in the width of the wall in which there's some rubber or something that expands and seals the interior when the two parts are tightened.
You could easily lock the box without resorting to screws that go through the case ... for example my mind goes to metallic zip ties or captive screws on the outside of the battery holding area.

I don't see where one could put some temperature sensors or a connector to export battery health data, I didn't see (maybe I missed it) how you'd do 3S, 4S, 5S batteries and how you'd do balancing when charging etc etc...

Hi, Thanks for the comments. That's generally off topic and nothing to do with the design I presented:

>>adding a lot of wire resistance with the springs
The electricity does not in any way travel through the springs... It goes through copper!!! sorry that's a complete misinterpretation. copper has 22% the resistivity of nickel, so my battery can take 460% more current compared to the equivalent of nickel.
The springs are mechanical, not electrical, they let you build 1KW in 30 minutes compared to 9 hours of spot welding, plus better recycling and safety, lower cost in tools, and many other advantages.

The only current limitation is the batteries, not the box, unless you want to discharge batteries in 20 minutes at 32 Watts a piece.

>>corrosion on the contacts
Nickel is completely rust-immune, so that's not possible. It's completely air-tight if you want it to be.

>>humidity to infiltrate along the shaft of those screws
The steel rods have rubber disks / elastomer washers, and the lid has a rubber gasket, air exchange of the box can be very carefully managed.

>> 3s 4s 5s and BMS balancing.
When you spot weld a battery, there is no armature for knocks and bumps and to protect BMS wires, and these boxes provide protection. You could jab it with a fork 50 times and it would be fine.
For 3s 4s 5s, you type 4s/5s in the free STL generator and print it on a printer. If you have a big BMS you can add 1x extra spoace to the series i.e. 4S 11p+1, and your BMS and wires are then protected inside. There's 1.5mm in between the cells, you can run thermistor wires in it.

This isn't something I would want (at least, not yet) but it seems well thought out to me  :-+


--- Quote from: dunkemhigh on November 01, 2021, 12:47:23 am ---it seems well thought out to me  :-+
--- End quote ---
Thanks a lot DunkmeHigh!!! I also designed some cell level fuses some time ago, except that they're not very necessary lol, seeing as lithium is hyper reliable these days lol


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