I’m not sure that is official Tesla.
Current will always bring heat, and heat is what triggers fuses, so using a wire as the fuse is fine. In fact the reason fuses trip in the first place is because they surpassed a temperature ceiling.
Where do you get the tabs for the cells? You have a talent for building packs. Awesome job!
Would this type of fuse setup be good for a 12s4p pack?
From my understanding, it shouldn’t really matter too much what size battery pack you use as long as you use fuse wire appropriate to the current rating of your cells. I’m using a very similar design to @chaka’s (although definitely not quite as professional looking with his custom 3D printed enclosures) and have had no issues. I’ve got a 10S4P pack. In my case, I’m using 20A fuse wire with LG HE4 cells which are rated at 20A continuous discharge.
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So i’d like to use 20A cells, therefore i’d like to use ~25A fuse wire. Someone knows what awg that would be?
Did you have a build thread of this 10s4p battery , we would love to how this was built ?
It really depends on your supply, I have had to test every spool to get my own specs. There is some variance from one supplier to the next. Somewhere in the range of 22-24 gauge should do it. You can also use resistor legs but they vary greatly in spec, some blow faster than others.
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could a similar approach be used with a slightly heavier gauge wire in order to better distribute the load but not act as cell level fusing? I really like what’s happening here.
That would defeat the purpose of the cell level fusing. They do not distribute the load any better than nickel strip, although the brass buss bar is less resistive than thin nickel strip. What cell level fusing does is prevent thermal runaway should a single cell become damaged resulting in increased resistance. If a cell is allowed to draw unlimited current it will also heat up the neighboring cells which causes their resistance to also go up resulting in a cascading effect.
This construction is more about safety of the battery and rider rather than an increase in performance.
Grin tech filmed a resistive load test to see what happens when a sealed 10s1p pack goes into thermal runaway.
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holy crap!
How did you test those wires? Do i need such a big power supply or is there a trick i dont know maybe?
No build thread sorry, didn’t end up taking many photos. Here’s a couple I took fairly early on though showing how I soldered the fuse wires.
My original plan was to build 5 separate 2S4P packs that could be connected together in series via bullet connectors so that I could pull the battery apart and take my board on a plane. However I ended up getting impatient waiting for a few things to arrive and ended up just wiring it all together into a single pack 
I’m going to pull the whole thing apart at some point when I’ve got some time and do redo my original modular idea but the main issue I’m having atm is deciding how best to secure the batteries together. Currently they’re just hot glued but I’m trying to find a more permanent solution that better handles the vibration without making the pack longer as I don’t have any more free space in my space cell enclosure. I might look at replacing the black wires with slimmer, flat brass rods or similar to reduce the thickness of the pack as well.
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Where did you find the right wire?
A local electronics wholesaler had a range of different sized fuse wires with various current ratings
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Do big name companies like Boosted and Evolve use this technique,… Hmmmmm ??
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Pretty sure my Evolve battery doesn’t have this. I don’t think it’s used much in ESK8 since it’s designed for saving parallel cells and we typically don’t have that many cells in parallel. chaka likes to use larger parallel packs so his implementation makes more sense. Boosted runs 12s1P I believe which doesn’t need cell level fusing.
Instead of guessing/calculating the amperage of wire. Why not buy actual fuse wire like the following: https://www.bunnings.com.au/hpm-8amp-16amp-fuse-wire-card_p4331623
It’s still used in some houses today and it’s only downfall was that you had to replace it instead of flick a switch as is used today in homes. With that said too. Has anyone thought of using trip switches?
For holding the cells in place why don’t you use fiberglass reinforce tape, it is thin and can hold the cells nicely.
Something like this?