I was asked to post here, as I’m part of a few battery groups on Facebook. I’m just starting development of a spring loaded “Tesla style” fuse wire welder attachment. Currently it’s being developed for the Nano spot welder, but I’m considering building a larger version for a Kweld or Malectrics. I’d love any feedback, suggestions, or criticism on the design. Any questions, ask away! Here is a video of V1.2 welding cells together as an example. To be clear this is NOT how I will be building packs! Just an example of welding fuse to cells. V1.3 coming soon…
EDIT: To be clear this is currently NOT for sale, it is a prototype and experiement. I will likely make the STL’s available for free and possibly build them to sell once I’m happy with the design.
Welcome
So…are we supposed to add nickel as usual(thus making the fuse kinda useless) or is this completely unrelated to esk8s?
I don’t see myself passing 80a+ through those teeny wires
Not sure about esk8 but the way I’ve seen this used before is to promote cell level fusing, so impossible for the cell to get overloaded (the wire melts at “x” current). I’d imagine this would only be for parallel connections.
The fuses link the lithium cell to a copper or nickel busbar. Each fuse by itself is sized to keep the cell safe and blow if there is a dead short or other significant problem. Running multiple fused cells in parallel to a busbar capable of 80A+ is how you’d build a pack using this particular method. Though I’ll admit, cell level fuses like these are less optimal for small, high power applications than they are for large powerwalls which is my main hobby.
But its main application is power cars and powerwalls. Which contain hundreds and thousands of cells. Which in turn allows for minimal amperage to pass through each cell. In those applications, I can understand the extra security of a cell level fuse. But we don’t have that luxury of space in our world
Thank you for the clarification and yes I can see the 80a busbar in the idea. But most used size here is 10 to 12 in series and 4 to 8 in parallel. That’s one hell of a fuse
Exactly. The fuses can be sized to the application as well. For 25A capable cells I might use a fuse that blows at 30A+ for instance. You do suffer from voltage drop, but if a cell catastrophically fails your pack doesn’t catch fire.
In any case this simplified fuse installation system is pretty fun. But I have a hard time seeing it applied here. We like to use brand new cells and have bms’s to assure good function of our packs
I know very little about electric skateboards, but you could easily build a low profile busbar. Guys in the powerwall groups even flatten copper pipes and bolt them together with crimped lugs for higher loads
