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Laser welded studs of screw in?

That 8Nm is based on strength of plastic housing holding terminal.
If you have a stud, most of the torque is expended in friction between nut and stud, and between nut and busbar.
If you can restrain those while tightening nut, the terminal/housing interface doesn't experience it.

With terminals like picture from cass3825 shows, it could be restrained by wrench.

If terminal was just an aluminum tab standing up with hole through it (like some battery types), tighten nut on bolt with two wrenches, and terminal/housing interface won't experience any of it. Plus you could use busbar or cable on both sides, 2x the area each getting same pressure.
yeah exactly. That terminal design is just dumb. 1000 other ways to make it safe even for an impact gun
 
If the terminals are aluminum and the studs are stainless what materials are welded?
 
If the terminals are aluminum and the studs are stainless what materials are welded?
The threaded stud seems to be press fitted (?) into a disk or washer shaped piece of aluminum (this aluminum disk/washer shaped piece is pointed out in the attached photo, courtesy of Lt.Dan)-- this assembly is then welded to the flat aluminum surface which forms the top of the terminal.
 

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Do the holes go through? Or is there a bottom?
Not sure, but if they don't it appears they could be drilled out and through-bolted with a backing nut as suggested above. In either case, a definite improvement over other options on the market!
 
If the terminals are aluminum and the studs are stainless what materials are welded?
I have attached a photo. The stud is stainless steel and the mount is aluminum. So aluminum is welded to aluminum.
 

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It would be great to see better connection points, the drilled and taps studs can be an issue, aluminium treads are risky at the best of times.

The welded on EVE studs, leave little contact area, but for my case, it was acceptable as i'm not drawing a lot of current

The twin threaded cells, posted by Cass, would be an improvement, like it was pointed out, allowing a mechanical grip on the stud to tighten is a better option than the current welded on studs.

At the end of the day, these cells are produced for commercial use, we are lucky vendors have offered us options, as most of us won't have a laser welder.
 
allowing a mechanical grip on the stud to tighten is a better option than the current welded on studs.
If the studs are properly welded it should not be a problem other than the surface area if loads exceed 150 amps. It was determined 4nm of torque (35 inch pounds) is equivalent to 700 pounds of axial force. Provided the contact area is clean that should be enough torque and was the maximum torque recommended if using grub screws. The aluminum in the terminals is very soft and very easy to strip...ask me how I know...lol. That's the main reason I would prefer welded studs.

Most manufacturers spec sheets I have seen recommend .5C rates even though the cells are capable of 1C rates.
 
yeah you should use only the original terminal (with screw in stud or directly a screw). I'm not sure why they are making these top-welded "terminals", it doesn't make any sense if you have any basic electrician knowledge. So in conclusion those making these terminals have no clue at all.
 
however I agree best in this case would be some sort of a 90° hole terminal standing up, so you can tighten it from both sides holding it with a wrench. Then you excert no force on the battery internals at all
 
The threaded stud seems to be press fitted (?) into a disk or washer shaped piece of aluminum (this aluminum disk/washer shaped piece is pointed out in the attached photo, courtesy of Lt.Dan)-- this assembly is then welded to the flat aluminum surface which forms the top of the terminal.
crap!
 
I would like to see these terminals at least with a hex collar nut (and M8 or M10 thread)! so you hold it with a flat wrench and tighten down against itself not against the cell body
 
Direct from EVE or Amy Wan from Shenzhen Luyuan offers that terminal option.
that thing seems still to be some "add on" on top of the original terminal with screw hole. I would not trust the connection between the two.

Best would be as I say a strip of thick aluminum with 1-2 lateral holes standing up and made from one piece of aluminum with the base.
 
I would like to see these terminals at least with a hex collar nut (and M8 or M10 thread)! so you hold it with a flat wrench and tighten down against itself not against the cell body

You want the busbars or leads clamped against aluminum (preferably plated so no oxide).
If clamped against collar of a stainless steel screw (or other material that isn't aluminum, copper, etc.) the high resistance of screw will make it get hot.
For those using "grub screws" in a female threaded terminal, an Allen wrench can hold the screw against turning while tightening nut. Makes it more difficult to use torque wrench; maybe crows foot with extension, and a 3rd hand (unless using a torque nut driver).
 
You want the busbars or leads clamped against aluminum (preferably plated so no oxide).
If clamped against collar of a stainless steel screw (or other material that isn't aluminum, copper, etc.) the high resistance of screw will make it get hot.
For those using "grub screws" in a female threaded terminal, an Allen wrench can hold the screw against turning while tightening nut. Makes it more difficult to use torque wrench; maybe crows foot with extension, and a 3rd hand (unless using a torque nut driver).
you didnt understand!

the original terminals should be hex-shaped (instead of egg-shapped) and some 10mm taller, so you can hold the terminal with a wrench while tightening the screw
 
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