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EVE LF280K welded studs flying off like a bunch of acrobats in a circus

PreppenWolf said:
If it was me and I had to use them because you have no other options, I'd drill the battery post and the removed threaded post and tap them #4-48. Use stainless set screws to connect the two along with a conductive epoxy. The center "post" will give you the equivalent of a 11/10 AWG wire and the epoxy should give you a bump as well.

I weld and I would personally not ask someone to TIG that unless you know they are an expert. I've known maybe two people in 20 years I'd trust to TIG tack those on and hope the battery doesn't get dorked due to the heat. If I was going to TIG it, I'd drill small holes in the washer in 6-8 places equi-spaced. Then use a 1/16" tungsten to just bang spots on hoping to get adequate penetration into the base stud through the hole.
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I would drill and tap, then stud then give a few quick zaps around the stud after cooling the battery overnight in the freezer.

I don't think the battery manufacturers that weld the busbars to the battery are using Lazer welds so I'm not sure why others on here don't think these can, if not tig welded, be spot welded on.
 
Brett V said:
You don't deserve to be ripped off. Go after the seller by whatever means you can.
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Good luck with that. You are dealing with a Chinese manufactured Product sold by a Chinese company. Think about it. If you bought it using a Credit Card from the US, the CC company has to refund the money after they perform due dillagence on your claim.
 
PreppenWolf said:
Oh I think it can. The issue is finding someone to do it for you.
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Well, yeah. You need a welder or a buddy with one. Not expensive but this is the DIY battery section. They should have at least a crescent wrench and old buzz box laying around.:sneaky:

Also, given the fact that they are coming off, I wouldn't trust the rest of the cells. Good place for a hot spot to form.
 
Brett V said:
So you just suck it up and accept a defective product?
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Checkthisout said:
Contest the charge on your credit card after giving them a bit more time to respond.

They are probably offshore which means the cc company probably won't get any money back but you will.
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Thanks, this is the plan.
18650batteries sell them for +$500 for the shipped 16cells vs these, but they have the beefy terminals and are allegedly better with test reports etc.
It's a shame because the ones I could test did have around 283Ah and 915Wh.
I'm going back to woodworking while this situation is sorted out.
 
Checkthisout said:
Why do you guys think these cells can't be welded with a simple spot/resistance weld?

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I'm not an expert, just read this somewhere that aluminum does not spot weld. Maybe it does in some specific situations. But batteries in that vid are not aluminum. And the thickness of material that is attached to the battery is a lot less substantial in the video.

Spot welding is much simpler and (I'd guess cheaper) than laser, so I'd be very surprised if EVE is laser welding where simple spot (resistance) welding would work.
Not trying to argue here but speaking as one amateur to another ;) after doing just a tiny bit more research.
 
Checkthisout said:
Drilling and tapping would be optimal but how deep can you drill into the terminal?
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There are some old threads with a lot of detail about tapping the terminals ..... most of them are about enlarging the tap after studs stripped out the original ones ..... I think @cinergi and others did some measurements of the depth of the original tap.
 
@Bob B
I think I'll hold off on buying the conductive epoxy and testing it. I'd like to have it in my shop "just in case" but it has a shelf life of 6month.
And if the batteries go back to seller, then it's just a waste of time and $44 for the tube of stuff.
BTW while looking around amazon i found another epoxy, several times more expensive that claims much lower resistivity.
 
Bob B said:
There are some old threads with a lot of detail about tapping the terminals ..... most of them are about enlarging the tap after studs stripped out the original ones ..... I think @cinergi and others did some measurements of the depth of the original tap.
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spec (somewhere) said 2.5mm depth - doable but barely
 
dielectric said:
@Bob B
I think I'll hold off on buying the conductive epoxy and testing it. I'd like to have it in my shop "just in case" but it has a shelf life of 6month.
And if the batteries go back to seller, then it's just a waste of time and $44 for the tube of stuff.
BTW while looking around amazon i found another epoxy, several times more expensive that claims much lower resistivity.
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Please update us when you get around to testing it.
 
Not to beat a dead horse, but after looking at the pictures, why do you guys think that thing is laser welded on there?

Looks like a simple spot weld to me. They push it down onto the terminal and then apply some current for a second or so making the weld.
 
Checkthisout said:
Not to beat a dead horse, but after looking at the pictures, why do you guys think that thing is laser welded on there?

Looks like a simple spot weld to me. They push it down onto the terminal and then apply some current for a second or so making the weld.
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Because they said it's laser welded ?
 
This is one of those situations where if you have the right tool, it's a quick attempt at a fix. But if you don't, it's kind of a WTF now?
 
Regarding returning faulty items are you sure you even have LF280K cells - my grade A ones look totally different... like this ..

GradeA-side_500x500.png
 
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