Prismatic cell terminals with crooked threads - is this typical?

[uberpixel]

Hopefully you used a credit card and can do a charge back. If the vendor expects me to fix his screw ups, they would quickly find out how much I make an hour. This is not acceptable.

I tend to agree with you on this one...

I enjoy the DIY aspect of this hobby as well as many others, but this part of the battery build was not expected to be a "whole 'nother project".

The great thing is that this (DIY) forum is full of people who are used to (or enjoy) figuring out a way to make things work in the face of adversity, and I really appreciate all of the suggestions on how to correct the issue and make these cells work, but the bottom line is that the vendor should not be sending batteries to customers with this poor level of quality control on something as critical as the terminal tapping.

Unlike some of the examples cited by others of stripped threads and such, these terminals were screwed up through no fault of my own...

Rather than just doing a credit charge back, I'm still trying to work with the vendor to resolve this issue in a positive manner.

-uberpixel

 

[Steve_S]

MacGyverism's. ?

 

[Just John]

I tend to agree with you on this one...

I enjoy the DIY aspect of this hobby as well as many others, but this part of the battery build was not expected to be a "whole 'nother project".

The great thing is that this (DIY) forum is full of people who are used to (or enjoy) figuring out a way to make things work in the face of adversity, and I really appreciate all of the suggestions on how to correct the issue and make these cells work, but the bottom line is that the vendor should not be sending batteries to customers with this poor level of quality control on something as critical as the terminal tapping.

Unlike some of the examples cited by others of stripped threads and such, these terminals were screwed up through no fault of my own...

Rather than just doing a credit charge back, I'm still trying to work with the vendor to resolve this issue in a positive manner.

-uberpixel

Maybe it's just me, but no way someone didn't notice that they repeatedly screwed up. More like "let's see how much we can mess with the rich westerners". This is a malicious screw up to me.

 

[Steve_S]

This is a malicious screw up to me.

Hang on a second there please. So there was a batch of cells that got drilled & tapped with a jig out of whack. This is more or less obvious because it looks pretty consistent. There isn't some dude sitting on a floor with a hand drill doing batches of cells at a time. That is also time-consuming and inefficient. Add to this, it appears that several vendors supplied similar defects in Lishen cells, which further adds to the "screwed up batch" point.

How the various vendors deal with it is another matter altogether. As well, is what can we do and what are our options when we encounter this sort of issue, because sadly, in some cases there may be no remediation, which again brings us back to the various vendors.

 

[Luthj]

Never assume malice when incompetence will equally suffice.

 

[Just John]

Never assume malice when incompetence will equally suffice.

I like Winston Churchill too, but whoever did this was either drunk or malicious. Normal people notice when things are that far from level.

 

[Bob B]

It is entirely possible no one ever put the studs in the threads to figure out how screwed up they really were .... just drill and tap them and send them out.
I doubt it is intentional, because they will be shooting themselves in the foot one the inferior product is discovered.
I think TOTALLY incompetent is more likely.

 

[Luthj]

I used to do quality assurance spot checks on some production lines. You would be amazed what can roll out of a highly standardized process when there isn't any final checks. In this case I don't think anyone bothered to check the threads with a stud. If they checked them with a short screw you may not notice.

If I do another order of the 280/272s, I think I will try to source them with aluminum studs laser welded on.

 

[Just John]

I used to do quality assurance spot checks on some production lines. You would be amazed what can roll out of a highly standardized process when there isn't any final checks. In this case I don't think anyone bothered to check the threads with a stud. If they checked them with a short screw you may not notice.

If I do another order of the 280/272s, I think I will try to source them with aluminum studs laser welded on.

In the 1980s, we noticed very distinct trends in specific date codes on chips and defects. Despite being manufactured in places like the Philippines, Malaysia, etc. The problem date codes all clustered around American holidays (like the 4th of July and Christmas). We finally figured out that the manufacturers (like TI, National Semiconductor, and Motorola) had a small core of US managers and inspectors that would go on vacation. When they were out, anything would be shipped.

 

[Frank in Thailand]

I read about the idea of bending the studs in the terminals so it stands straight.

While I can support the idea of bending, not to do it inside the terminal.
With my recent experience it's clear that you can't apply force onto the terminals!!
Anything close to/over 8Nm torque would twist the terminal out of its plastic holding.

I don't know how much pressure you would need to bend your studs, if they are stainless... Probably more then the terminal can handle.

Making the ofsett outside the terminal and wobble twist it in, ending with 90 degrees ...

Your all good to go.

The pulling force still will be uneven, perhaps Loctite or JB weld can help compensate.

 

[djkarau]

Would it be possible to grind/file a flat washer to match the angle (or close to) that is needed to have a lock washer sit flat on the top of the washer and the bottom of the washer sit flat on the buss bar?

 

[Frank in Thailand]

Possible,
But grinding washers is a lot more work then putting 6mm thread in a vice, and bend it a little....