I WARNED YOU ALL! MB31/MB30 huge issue terminal snapping off

[Alkaline]

Well well well, didn't I tell you all, you better wait for these new cells to establish some cred before buying ! Turns out the terminals are snapping off, now we don't know if these are EVE official terminals or a third party welding knock off terminals, but so far we know EEL, 18650batterystore, and maybe Nkon appear to have these in stock and they are basically popping off like coke can tabs:

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

Sep 11, 2024

Where the lugs on the EVE batteries are welded to the electrode is really tender. I've read a couple of other threads stating they've had issues with them coming off when tightening the bolts. - it's not just me being stupid.

disclaimer - I've been using tools for the last 53 years, my mom gave me a took kit when I was 7 and I've been messing things up since. I have a very good feel for "tight" and such. I'm also a machinist/fabricator so I can claim that I know what I'm doing, for the most part - including screw ups... (I like to call them teaching moments)

I had to...

• K-fab
• Replies: 64
• Forum: Up in smoke... learn from my mistake!

• 
• 

So just like the fiasco of the v1/v2 280K cells, you better put the brakes on until you know for sure if the cells you are getting have legit terminals. We also don't know if this issue just affects the MB31 or if this is now also affecting the 280K and 304 so make sure you ask your seller these details.

 

[AntronX]

Those terminals look very porous. Were they die cast aluminum?

 

[EastFalcon]

Ohh yuk that is bad! No issue with SFK terminals or eve official terminals on the 230s.

 

[DIYrich]

I have eve lf280k batteries from a year ago with those terminals, and have not had any problems. Doesn't look like much force is being applied. Looks like cheap welding.

 

[Brucey]

I have eve lf280k batteries from a year ago with those terminals, and have not had any problems. Doesn't look like much force is being applied. Looks like cheap welding.

Improperly setup welding machine(s) I'm guessing. Reading quickly initially I thought it was the actual terminals within the battery rotating. *Hugs my REPT 280s*.

 

[prosier]

I told everyone from day1 to ask for the single m6 studs...

 

[ArthurEld]

I have the new terminals and the old terminals.
I prefer the new terminals very much.
And I suspect this problem is from improper welding.
People beating down the price are asking for trouble.

 

[Tulex]

My MB31s came with the 6mm stud. Even those you are only supposed to torque to I think 5Nm. I think the 304ah Eves were higher than that.

 

[Brucey]

I have the new terminals and the old terminals.
I prefer the new terminals very much.
And I suspect this problem is from improper welding.
People beating down the price are asking for trouble.

Old terminals being the 6mm studs?

 

[Brucey]

My MB31s came with the 6mm stud. Even those you are only supposed to torque to I think 5Nm. I think the 304ah Eves were higher than that.

All the eves from Docan show 6mm stud as well

 

[DIYrich]

I told everyone from day1 to ask for the single m6 studs...

Wouldn't improper welding setup affect any terminal that is welded on?

 

[740GLE]

It would have been great for that guy to use a digital adapter to capture peak torque to strip off the terminal, my guess is <3nm.

As for testing the terminal, I’d never fasten just one bolt. Not saying this would save shitty welding but imo is just good practice.

On my Eve terminals from Luyaun, I placed the bus bar then threaded down both bolts by finger tight, by having both bolts threaded you have a little more resistance to rotating the actual terminal. Maybe it’s in my head, but I felt better.

Also once the spring washers compressed there was minimal rotation to hit 7nm, maybe 1/8 a turn.

 

[ArthurEld]

Old terminals being the 6mm studs?

Yes, I prefer the 2 hole terminals over the 6mm studs.
I stripped out a couple studs and also had bad connections with the 6mm studs.

 

[SparkyJJO]

Wouldn't improper welding setup affect any terminal that is welded on?

Yes it can but there is inherently more leverage on the weld of the 2 bolt terminals.

 

[prosier]

Wouldn't improper welding setup affect any terminal that is welded on?

These dual hole terminal add an extra point of failure as pressing on the screw hole just bends the whole thing sideways. Thats not the case with just m6 studs. And there is no bennefit for taking dualhole terminals...

 

[Tiziano]

I have 4 EVE MB31 from NKON with double screw terminals. NKON informed me before purchasing that the terminals were not original EVE, because they were not yet designed for this battery. For screw terminals this cannot be done, but for these terminals I built a counter key that embraces the terminal and does not transmit the stresses. The key is made of steel covered with strong insulating tape. I did not know about this welding problem.

 

[740GLE]

These are the terminals you’re looking for.

 

[Skypower]

These are the terminals you’re looking for.

I really like that weld. From appearance it looks bright, wide and the flatness leads me to think that it probably has good penetration.
A year ago in got shipment from Eel and FedX did some destructive testing on some of the welds. They all passed but the post didn’t fare too well The weld doesn’t look as good as the picture above but none have failed. Being curious, I used an internal resistance meter between the posts and the terminal on all of them including the damaged ones. They all had extremely low resistance (solid connection). I would think that if this lot had poor welds like those in the video where they twisted off and the welds looked like they only a few spots of weld adhesion that measuring with an internal resistance meter would would stand out greatly.
I can only imagine what could happen if someone was pulling a lot of current through a compromised terminal and it took that moment to totally let go I hope that this is only small run of these and the manufacturer does their best to recover and replace the affected lots. I would like to see a close up of the welds that failed(video). Wondering if there’s an obvious look to them. Here’s the weld pic of the Eel cell from a year ago and FedX weld test pic.

 

[rhino]

I thought that EVE only provides the blank flat terminal on top and it is up to a third party to add whatever terminal they need on top?

 

[Brucey]

I thought that EVE only provides the blank flat terminal on top and it is up to a third party to add whatever terminal they need on top?

I believe they send it to a third party for the welding of terminals if desired.

 

[houseofancients]

I thought that EVE only provides the blank flat terminal on top and it is up to a third party to add whatever terminal they need on top?

This is correct, same goes basically for all cell manufacturers

 

[Katieeee]

All cells from manufacturers do not come with terminals, they are all welded by a third party.

 

[ArthurEld]

It looks like some of them are bent during shipping. They need to be put on properly. And they need to be shipped properly.

 

[Skypower]

It looks like some of them are bent during shipping. They need to be put on properly. And they need to be shipped properly.

Yeah. It would have been simple to have pockets in the closed cell foam pads that clear the terminals and vent port so no matter what gorilla handles them they wont get damaged. Some distributors must be doing that now.

 

[DIYrich]

These dual hole terminal add an extra point of failure as pressing on the screw hole just bends the whole thing sideways. Thats not the case with just m6 studs. And there is no bennefit for taking dualhole terminals...

One benefit is stripped stud: With hole, you can put a nut underneath it to secure a threaded rod.

It would have been great for that guy to use a digital adapter to capture peak torque to strip off the terminal, my guess is <3nm.

It didn't look like he applied much force at all. Even if he was gentle at making the connection to a bus bar, I wouldn't trust the weld to hold during normal battery flexing, even with a flexible bus bar.