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You can put the lugs back on the EVE batteries - CAREFULLY.

Where did you order these cells from? These look like knock off eve dual threaded terminals.

Do you see threaded inserts in each of the terminals? Looking at the picture it sure looks like it’s non threaded insert, just bare threaded aluminum.
I got them from the 18650 Battery Store - Here's the battery
There are no inserts in any of the lugs, just two 6x1.0 threaded holes in each aluminium lug. (metric spelling of aluminum because they're metric threads ;))
 
Interesting, I thought they only got legit Eve terminals (threaded inserts).

Maybe Eve changed these terminals on the MB30/31.
 
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This is crazy! I could have ended up with these mickey mouse terminals! I almost ordered from them last year form 18650batterystore! Wow the Sun fun kit guys were right they told me I would regret the Eve terminals! Actually this looks like knock off eve terminals?
 
I got them from the 18650 Battery Store - Here's the battery
There are no inserts in any of the lugs, just two 6x1.0 threaded holes in each aluminium lug. (metric spelling of aluminum because they're metric threads ;))

Bro that is BS get your money back, they are sponsor on the forum contact them and tell them they need to eat this cost.
 
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There's enough meat available to weld that it ought to be much stronger than what the threads can take without stripping out.
I had thought this style welded terminal was the LiFePO4 God's answer to DIY battery problems.

I'm going to be assembling with CATL 4s packs having welded terminals. I figure the cell manufacturer would get it right.
 
There's enough meat available to weld that it ought to be much stronger than what the threads can take without stripping out.
I had thought this style welded terminal was the LiFePO4 God's answer to DIY battery problems.

I'm going to be assembling with CATL 4s packs having welded terminals. I figure the cell manufacturer would get it right.
So now in addition to possible shipping damage where those are pushed down at an angle due to impact from above, these may be knockoff non insert terminals to boot? Maybe running change to save a few cents?
 
Insert would refer to threads. If not pure dead-soft aluminum, could be OK. My Square-D box lugs are aluminum with aluminum setscrews.

I assume the laser welds are shallow, too little tear-away strength.
Likely still better torque resistance than peel resistance, which would concentrate force on one spot like pull-off can top.

I think a wrench should be used to restrain terminal as shown in RCinFLA's drawing.

A torque wrench causes radial load and tilting of the bolt, which increases friction on threads and changes clamping force achieved.
I like to use a socket extension and support head of torque wrench with palm of other hand, so only torque not torsion applied. But in this case you would need a 3rd hand to hold that other wrench.
 
I bought 64 MB31's couple of months ago from 18650. Knock on wood, I had no issues.

Hard to be sure but the packing looks like originally done by EVE, with four cells per box along with screws and flexible bus bars. It does not look like 18650 even opened the boxes. All 64 cells' SoC were almost identical with rested unloaded terminal voltage ranging from 3.2637v to 3.2650v which is 21.7% SoC.

In groups of 16 cells series connected to JK PB BMS, I applied 8 amps charging for 11 hours to bring them up to about 50% SoC. They ranged from 3.3007v to 3.3011v rested open circuit voltage which is close to 50% SoC.

First thing I did was throw away the included screws and replaced with grub screws, washers and nuts with Allen wrench inserts on grub screws to prevent torque on battery terminal posts.
 
Insert would refer to threads. If not pure dead-soft aluminum, could be OK.
Ah, a terminology issue. Inserts to me are thread repair coils, like heli-coils.
The aluminum is definitely not soft enough just to thread a 6mm bolt into. Just trying that would tear the terminal off really quickly.
I'm going to guess that the lug is made from something like a 2000 or 3000 series aluminum which is soft and weldable and just sort of has the same look/color/feel to it. - too many years of working with the stuff, I can tell the differences in alloys by feel/look.
 
Insert means Heli-coil to me, too. Or solid threaded inserts, which I've also used.

The threads tapped directly into cell terminals, 6mm and only 4 threads deep, people reported stripping easily.
Tapped threads in aluminum welded terminals could be OK if suitable alloy.
My days playing in school machine shop are long, long ago. Do a little welding, never had mig/tig/heliarc so I'm not familiar with aluminum.
 
Bad soldering is a problem, threading can solve it, I think using heli-coils is a problem because it increases the internal resistance compared to other cells. I didn't know about this problem, but to tighten the screws on my new batteries I built a wrench like RCinFLA in post #20. The wrench is long and takes the whole terminal.

See here at post #16

 
Where did you order these cells from? These look like knock off eve dual threaded terminals.

Do you see threaded inserts in each of the terminals? Looking at the picture it sure looks like it’s non threaded insert, just bare threaded aluminum.
I got them from the 18650 Battery Store. <---- link is directly to the batteries I ordered.

Okay what is it with everyone saying "inserts" and non threaded insert? Someone show me a picture of one of these lugs with the insert.

This is a threaded lug hole. Plain and simple. Drill hole, run tap through it. No "threaded insert".

IMG_8723.jpeg

This is a threaded insert - notice the the color difference around the hole? Probably a stainless threaded insert in aluminum.

insert.jpeg

So do some of the EVE cells come with a stainless (or other steel) threaded insert like in the picture right above this sentence?
 
Why would they do that tiny little weld ring around the existing terminal instead of say just casting the terminal with the 2 holes as a unit and use?
 
I got them from the 18650 Battery Store. <---- link is directly to the batteries I ordered.

Okay what is it with everyone saying "inserts" and non threaded insert? Someone show me a picture of one of these lugs with the insert.

This is a threaded lug hole. Plain and simple. Drill hole, run tap through it. No "threaded insert".

View attachment 245023

This is a threaded insert - notice the the color difference around the hole? Probably a stainless threaded insert in aluminum.

View attachment 245027

So do some of the EVE cells come with a stainless (or other steel) threaded insert like in the picture right above this sentence?

Here’s my luyaun 280k v3 cells, clearly see the difference in color of the threads and the terminal. You can even see the tang of the end of the coil.

Also notice how the welds look much different than your cells.
 

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That looks like a good weld, why are a lot of the ones we see looking cracked?
 
Yup, that's a threaded insert.
I don't have those and now I'm feeling sad and left out. ☹️

😋
Looks like maybe those garbage terminals are only on the mb31? Look at the pictures of the 280 v3 terminals, they have the threaded inserts and hopefully better welding

Screenshot_20240920_004321_Gallery.jpg

 
If the welds are weak, the post series resistance may also be greater.

I don't like thread helical coil inserts. I have had some bind up when trying to loosen screw.
I prefer just tapped aluminum thread with a Grub screw.
 
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If they are not real eve terminals why did they design them this way? They could have done what sun fun kits did with these:


Super strong and is machined aluminum for good contact with a pressed in steel hex bolt.
 

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Female thread would accept bolt or grub screw of various length to accommodate busbar(s) thickness.
Can also be repaired, oversize or heli-coil insert.
 
If the welds are weak, the post series resistance may also be greater.

I don't like thread helical coil inserts. I have had some bind up when trying to loosen screw.
I prefer just tapped aluminum thread with a Grub screw.

NOTE - below is not a critisism - I would probably have done the same if I couldn't have gotten a new cell under warranty.

I wonder with the repair the OP did if there is some resistance where the terminal is bolted back on that could cause a problem down the road. For example, when it broke off originally if it left a burr on the metal that doesn't let it fully seat and get good contact and over time it causes heating and an issue? You certainly can't just torque it down like you would on something you can backstop with another wrench.

btw - from a suggestion earlier - a Vevor micro-tig welder goes for only $200 ... that is DC verse AC/DC ... so not sure it would work here since you would normally use AC current for aluminum. - least that is what I read - one of the welders in the group would know better..... For an AC/DC version it is closer to $500~$700 - I would have to break a lot off to make that worth while and also learn to do the fix without exploding the battery.
 

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