NIPPLE slip

[HRTKD]

Spot welding even .062 aluminum sheet is tricky. We tried this some years ago using a standard Miller 240V clamp spot welder and quickly learned that getting reliable connections by manually pulsing the welder was impossible. Sometimes we’d get a strong weld and then there would be pieces that popped apart easily. I’m sure aluminum can be spot welded, but it takes critical control of many variables to make it work and that isn’t going to happen for backyard setups.

The laser welding we see on some of these battery terminals looks like a better solution. There is an actual weld bead that can be inspected and the laser limits the heat zone so the battery isn’t damaged during welding.

No doubt in my mind that laser welding is the way to go. I spot weld with my TIG only t get two parts to hold together so I can do some real welding. The heat affected zone would be significant if I was doing the welding. I'm inexperienced at it. I was simply thinking out loud as if I had some cells to play with that weren't expected to be used ever again.

 

[noenegdod]

Seriously?
....

Very. I made an obvious joke in another thread and it was deleted.

 

[noenegdod]

Spot welding even .062 aluminum sheet is tricky. We tried this some years ago using a standard Miller 240V clamp spot welder and quickly learned that getting reliable connections by manually pulsing the welder was impossible. Sometimes we’d get a strong weld and then there would be pieces that popped apart easily. I’m sure aluminum can be spot welded, but it takes critical control of many variables to make it work and that isn’t going to happen for backyard setups.

The laser welding we see on some of these battery terminals looks like a better solution. There is an actual weld bead that can be inspected and the laser limits the heat zone so the battery isn’t damaged during welding.

You are correct. You would never attempt to weld aluminum on a temperature sensitive component like this with TIG. If these terminals were steel/stainless you could probably get away with it if you were patient enough to let the heat leave the part between each tack.

 

[Supervstech]

Seriously?
....

I mean... for accuracy and all...

 

[fafrd]

I’m very interested in this type of terminal for my next battery purchase. Where did you find this information?

Double Eve M6 Terminals 280ah

I'm in the process of getting some EVE LF280Ks and being offered these new terminals (this is direct from eve) . I've never seen these before do they need special bus bars, has anyone seen any battery building videos with these? Thanks alex

diysolarforum.com

 

[noenegdod]

Double Eve M6 Terminals 280ah

I'm in the process of getting some EVE LF280Ks and being offered these new terminals (this is direct from eve) . I've never seen these before do they need special bus bars, has anyone seen any battery building videos with these? Thanks alex

diysolarforum.com

Those are 100x better than the directly tapped terminals, as long as they do a good job welding them on. The alloy should be less susceptible to tearing out but there is also far more depth so even if it is still soft it will tolerate abuse better. One thing to watch is you now have the opportunity to apply more torque to the terminal itself. If you torque the fastener on the left, the terminal will see more torque than the fastener. If you torque as is being done on the right the terminal will see less torque than the fastener.

 

[fafrd]

Those are 100x better than the directly tapped terminals, as long as they do a good job welding them on.

As these are apparently being welded and sold directly by Eve, who has designed and manufactures these cells for use in EVs, I would have orders of magnitude more confidence in the weld of these terminals than any terminals welded on by third parties…

The alloy should be less susceptible to tearing out but there is also far more depth so even if it is still soft it will tolerate abuse better. One thing to watch is you now have the opportunity to apply more torque to the terminal itself. If you torque the fastener on the left, the terminal will see more torque than the fastener. If you torque as is being done on the right the terminal will see less torque than the fastener.View attachment 69301

I would not apply any torque to these terminals - I’d Loctite in grubscrews and use brass nuts with a calibrated torque wrench as we have been doing on the ‘direct threaded’ terminals.

I’d probably even go to the trouble of positioning a wrench on the rectangular metal bar if I was concerned there was much of any real torque being applied to the weld…

 

[noenegdod]

As these are apparently being welded and sold directly by Eve, who has designed and manufactures these cells for use in EVs, I would have orders of magnitude more confidence in the weld of these terminals than any terminals welded on by third parties…

Is there a better chance? Sure, maybe. That isnt what I was saying.

I would not apply any torque to these terminals - I’d Loctite in grubscrews and use brass nuts with a calibrated torque wrench as we have been doing on the ‘direct threaded’ terminals

This does nothing to address torque applied to the battery terminal as I had described. All this does is sacrifice clamping pressure on a connection that is probably capable of tolerating much higher torque.

I’d probably even go to the trouble of positioning a wrench on the rectangular metal bar if I was concerned there was much of any real torque being applied to the weld…

This is the only real way to prevent torque being applied to the battery terminal itself.

 

[fafrd]

Is there a better chance? Sure, maybe. That isnt what I was saying.


This does nothing to address torque applied to the battery terminal as I had described. All this does is sacrifice clamping pressure on a connection that is probably capable of tolerating much higher torque.

My point was that aluminum threads are soft enough that Isould not take the risk of using them ‘directly’ by torquing bolts into them (and removing those bolts for disassembly). A ‘use-once’ strategy of getting a stainless grubscrew engaged and locked-in (never to be removed) is a much better approach to avoiding the possibility of stripping aluminum terminal threads…

This is the only real way to prevent torque being applied to the battery terminal itself.

Yes, if you really want to go nuts with the clamping force you apply to your lugs/busbars, locking in the maximum number of stainless grubscrew threads with Loctite Red and then torquing down a brass nut from above while securing the rectangular aluminum ‘base/bar’ from below with a wrench should allow you to safely apply torque in excess of 45 inch-lbs…

 

[noenegdod]

My point was that aluminum threads are soft enough that Isould not take the risk of using them ‘directly’ by torquing bolts into them (and removing those bolts for disassembly). A ‘use-once’ strategy of getting a stainless grubscrew engaged and locked-in (never to be removed) is a much better approach to avoiding the possibility of stripping aluminum terminal threads…

Yes, if you really want to go nuts with the clamping force you apply to your lugs/busbars, locking in the maximum number of stainless grubscrew threads with Loctite Red and then torquing down a brass nut from above while securing the rectangular aluminum ‘base/bar’ from below with a wrench should allow you to safely apply torque in excess of 45 inch-lbs…

• You have no idea what alloy the weld on terminal is made. The new terminal could very well be made of an alloy that can easily tolerate repeated use and not require the application of a permanent stud. Get some cells, do some research, ask the manufacture some quesitons but please quit making assumptions. It is only a "much better approach" if the new terminal threads are as delicate, short and poor quality as the ones that were threaded directly into the battery terminals.
• Torquing a bolt into the threads is the same/similar as torquing a nut onto a stud in terms of torque being applied to the welded connection and the batteries terminal. There is still a force being applied to the welded connection and therefor the battery terminal unless you are holding welded terminal.
• Its not "going nuts" to apply the torque spec for a given fastener. You want the maximum clamping force at the connection.

 

[fafrd]

• You have no idea what alloy the weld on terminal is made. The new terminal could very well be made of an alloy that can easily tolerate repeated use and not require the application of a permanent stud. Get some cells, do some research, ask the manufacture some quesitons but please quit making assumptions. It is only a "much better approach" if the new terminal threads are as delicate, short and poor quality as the ones that were threaded directly into the battery terminals.

Use of a harder allow would be great, but until that’s been confirmed, I’m an ‘err on the side of caution’ type of guy…

The only ‘benefit’ to using aluminum threads repeatedly is convenience. The hassle of even a 1% chance of stripping an aluminum terminal thread makes that convenience not worth it (at least to me, who has now had to deal with retapping 3 threads…).

• Torquing a bolt into the threads is the same/similar as torquing a nut onto a stud in terms of torque being applied to the welded connection and the batteries terminal. There is still a force being applied to the welded connection and therefor the battery terminal unless you are holding welded terminal.

In terms of force being applied to the aluminum threads, absolutely.

In terms of stainless-on-aluminum galling, absolutely not. Once you Loctite in a stainless grubscrew, your aluminum thread will be safe until you apply so much force that you sheer it off.

Each and every time you unthread a stainless bolt from an aluminum thread, you will remove some aluminum and ‘wear’ (degrade) the thread.

As far as torque, I believe we are in agreement, but the primary reason I am recommending the use of secured grubscrews is ‘better’ than direct use of the aluminum thread with stainless bolts is thread wear…

• Its not "going nuts" to apply the torque spec for a given fastener. You want the maximum clamping force at the connection.

Well first, there is no ‘spec’.

And second, once you find the appropriate curve showing contact resistance versus psi for a copper-on-aluminum connection, you will see that there is a point of diminishing returns above which you can ‘go nuts’ if you want, but you’ll likely be taking additional risk (of sheering threads) for little meaningful benefit…

 

[noenegdod]

Use of a harder allow would be great, but until that’s been confirmed, I’m an ‘err on the side of caution’ type of guy…

Find out what the terminal is made of and they you actually have something to err on. Right now you are still making assumptions and potentially steering people in the wrong direction. Actually know what you are talking about before making recommendation.

The only ‘benefit’ to using aluminum threads repeatedly is convenience. The hassle of even a 1% chance of stripping an aluminum terminal thread makes that convenience not worth it (at least to me, who has now had to deal with retapping 3 threads…).

And what happens if you accidently damage threads of your now glued in stud (mechanical damage or an accidental short). Now you have lost all the use you could have had with the aluminum threads and the fix of a damaged stud carries far more potential down side than trying to fix female threads in aluminum. A bit more than convienience.

In terms of stainless-on-aluminum galling, absolutely not. Once you Loctite in a stainless grubscrew, your aluminum thread will be safe until you apply so much force that you sheer it off.

Stainless/aluminum galling is far less an issue than stainless/stainless. The fix for Stainless/aluminum is simply lubricate or even better yet, dont use stainless. There is no point for most all application. Im sure you will disagree with that but it is pointless in this application other than the feeling of being special you get from using it.

Each and every time you unthread a stainless bolt from an aluminum thread, you will remove some aluminum and ‘wear’ (degrade) the thread.

Then stop taking them in and out, and quit using stainless.

Well first, there is no ‘spec’.

The fasteners have a specification. The threaded holes in the crappy soft aluminum used on the battery post we all have do not have a spec. That is not what we are talking about. We are talking about a completely different arrangement with unknown material. Again, actually find out what the material is before making assumptions and potentially sending people in a direction based on ignorance.

And second, once you find the appropriate curve showing contact resistance versus psi for a copper-on-aluminum connection, you will see that there is a point of diminishing returns above which you can ‘go nuts’ if you want, but you’ll likely be taking additional risk (of sheering threads) for little meaningful benefit…

I was told I had to change my reply:

What technical reference do you have to support this statement?

 

[fafrd]

Find out what the terminal is made of and they you actually have something to err on. Right now you are still making assumptions and potentially steering people in the wrong direction. Actually know what you are talking about before making recommendation.


And what happens if you accidently damage threads of your now glued in stud (mechanical damage or an accidental short). Now you have lost all the use you could have had with the aluminum threads and the fix of a damaged stud carries far more potential down side than trying to fix female threads in aluminum. A bit more than convienience.


Stainless/aluminum galling is far less an issue than stainless/stainless. The fix for Stainless/aluminum is simply lubricate or even better yet, dont use stainless. There is no point for most all application. Im sure you will disagree with that but it is pointless in this application other than the feeling of being special you get from using it.


Then stop taking them in and out, and quit using stainless.


The fasteners have a specification. The threaded holes in the crappy soft aluminum used on the battery post we all have do not have a spec. That is not what we are talking about. We are talking about a completely different arrangement with unknown material. Again, actually find out what the material is before making assumptions and potentially sending people in a direction based on ignorance.


And of course, you know exactly what this is, right? You have tested it or have a resource you can point people to so they can make an educated decision. Of course you wouldnt be making an assumption or talking out your a$$ on this, right?

Aluminum bolts into aluminum threads may be even better than stainless grubscrews in aluminum threads (and would provide the ‘convenience’ / accident-recovery you seem to think is so important).

I looked for aluminum grubscrews but they pretty much don’t exist (custom).

I wish to god I had someone here on this Forum warning me to be as careful directly exercising the threads tapped into soft aluminum terminals with bundled stainless bolts as I’m suggesting now. No doubt / hopefully the alloy being used by Eve is harder than what they’ve used in the cell terminals, but I wouldn’t want to be the guinea pig and would await others to prove there is no issue before torquing stainless bolts into those aluminum threads with abandon.

We’re having this exchange about a new terminal architecture that, to my knowledge, exactly one member on this Forum has committed to (and which I introduced to this specific thread).

For the vast, vast majority of members, any cells with threads will be of the soft aluminum type where every warning I’ve offered is more than warranted.

 

[noenegdod]

Aluminum bolts into aluminum threads may be even better than stainless grubscrews in aluminum threads (and would provide the ‘convenience’ / accident-recovery you seem to think is so important).

I looked for aluminum grubscrews but they pretty much don’t exist (custom).

I wish to god I had someone here on this Forum warning me to be as careful directly exercising the threads tapped into soft aluminum terminals with bundled stainless bolts as I’m suggesting now. No doubt / hopefully the alloy being used by Eve is harder than what they’ve used in the cell terminals, but I wouldn’t want to be the guinea pig and would await others to prove there is no issue before torquing stainless bolts into those aluminum threads with abandon.

We’re having this exchange about a new terminal architecture that, to my knowledge, exactly one member on this Forum has committed to (and which I introduced to this specific thread).

For the vast, vast majority of members, any cells with threads will be of the soft aluminum type where every warning I’ve offered is more than warranted.

The worst thing you can do is put materials that gall together. Use a stainless nut on a stainless bolt the chances of galling goes way up. Aluminum fastener into aluminum, same thing.

Since you and I bought our cells there have been hundreds if not thousands of posts regarding the issue of failed threaded terminals. This is different. You are trying to apply what you know to a completely different architecture. Quite possibly the only similarity between what you were doing and this new design is the fact that the terminals are both some kind of aluminum. Other than that basically nothing you are saying is of any direct relevance.

What was the point of any of that other than an attempt to deflect and save face? What a waste of your time typing it and everyone elses time reading it. Nothing above was relevant to this cell.

 

[cinergi]

So some of my batteries have decided to loose their TOPS it seems ... some of the batteries i got a while back from a supplier I no longer use, is starting to have the tops of the batteries pop off ... looks like they may have used some form of arc-welding or spot welding to zap the terminals in place but they are obviously not holding ...

I would rather not try to drill my own terminals holes so does anyone have an idea of either how I can reattach these tops -- OR do you have a better plan ... I may be wrong but it looks like its aluminum on aluminum .... aaaggghhhh


View attachment 68871

It seems like you'd need to find a way to get them LASER welded back on. Otherwise you'd have to find a way to remove all the other tops so that the bus bars would line up and to achieve similar resistance values (or find a way to create an electrically-solid shim). I'd thoroughly check all the other tops ... if it were me, I'd be very worried that some have relatively high resistance values and will heat up under load.

 

[NCSolarGarage]

I don't have these cells yet (they're on order from Jenny), but in the pictures I've seen, it almost looks like there is a thread insert in the hole. If so, that would change the direct thread arguement, imo. Link provided below as example.

https://images.squarespace-cdn.com/content/v1/5d638ee89a16e40001315e0e/1567004980857-UR5Z1EEASG5Y0AIHEG2J/Cell-ETC-LFP176S_sig-innotech.com?format=750w

Are they using inserts in these threaded holes?

 

[noenegdod]

It certainly looks like it to me!

 

[fafrd]

I don't have these cells yet (they're on order from Jenny), but in the pictures I've seen, it almost looks like there is a thread insert in the hole. If so, that would change the direct thread arguement, imo. Link provided below as example.

https://images.squarespace-cdn.com/content/v1/5d638ee89a16e40001315e0e/1567004980857-UR5Z1EEASG5Y0AIHEG2J/Cell-ETC-LFP176S_sig-innotech.com?format=750w

Are they using inserts in these threaded holes?

Wow, that’s great!

 

[Sanwizard]

Wow, that’s great!

I am interested in these cells from Seplos. The connections look great.

 

[fafrd]

I am interested in these cells from Seplos. The connections look great.

Those look nice too, but what metal have they used?

If Aluminum, that looks like a great solution.

If Stainless, not.