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

EVE 280s are sold in different configurations. The one you illustrated is suposedly an EVE full specification cell as sold by Fogstar as grade A. Most are supposed to be cells that don't meet the standard for use in EVs and are resold by various dealers, generally with 6mm studs. These are the version most commonly discussed here.

Read Fogstars take. https://www.fogstar.co.uk/blogs/fog...e-grade-a-and-grade-b-lifepo4-prismatic-cells
 
So are they made intentionally to be grade A or B, or do they just change the terminal type after testing them - i.e. when they know whether they made it to grade A or B? Seems a bit odd to me.
 
dielectric said:
Because they said it's laser welded ?
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It would be around the outside circumference if it was.

That's just a normal spot or "cold" weld. Poorly done with no oxygen purge etc.
SeaGal said:
So are they made intentionally to be grade A or B, or do they just change the terminal type after testing them - i.e. when they know whether they made it to grade A or B? Seems a bit odd to me.
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What electric car sold here in the US, uses these large rectangular cells?
 
AIUI from the factory they don't come with terminals, they just have a flat surface as seen in the studless pictures. The terminals are added either by EVE in the case of the twin terminal or resellers in the case of the single stud.
 
Checkthisout said:
What electric car sold here in the US, uses these large rectangular cells?
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Probably none, I believe that the main market is Chinese vehicle manufacturers.

I find it hard to believe that 280A maximum discharge rate is enough for a vehicle. My 400Ah Winstons can discharge at 3C or 1200A. However it's probably OK for very small limited performance vehicles, or could be paralleled for greater discharge rates.
 
billt1827 said:
Probably none, I believe that the main market is Chinese vehicle manufacturers.

I find it hard to believe that 280A maximum discharge rate is enough for a vehicle. My 400Ah Winstons can discharge at 3C or 1200A. However it's probably OK for very small limited performance vehicles, or could be paralleled for greater discharge rates.
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Maybe low speed/performance small vehicles and paralleled cell banks.
 
billt1827 said:
AIUI from the factory they don't come with terminals, they just have a flat surface as seen in the studless pictures. The terminals are added either by EVE in the case of the twin terminal or resellers in the case of the single stud.
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That's interesting. So resellers need to have welding capability ??️?? and hence a failure of stud is the resellers fault? If so, I'm surprised some resellers haven't designed their own better terminals.
 
SeaGal said:
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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I've no illusions about grade A. I have read enough on this forum to ignore the sellers grade claims.
I'm completely ok with the cells except for detachable attachment points ?
I checked every QR code all EVE LFK280.

I did email them before purchasing asking about the kind of terminals they sell. They said "welded studs".
 
SeaGal said:
That's interesting. So resellers need to have welding capability ??️?? and hence a failure of stud is the resellers fault? If so, I'm surprised some resellers haven't designed their own better terminals.
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I'm sure they have 10 capable shops along the route batteries take from manufacturer to their warehouse.
I think my batch was done on the truck buy some dude with a spot welder powdered off the same battery he was welding. While in transit.
 
dielectric said:
I'm sure they have 10 capable shops along the route batteries take from manufacturer to their warehouse.
I think my batch was done on the truck buy some dude with a spot welder powdered off the same battery he was welding. While in transit.
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My take is that, when you win your cc dispute, you're going to get your money back AND be able to keep the cells.

You literally just came up with the solution in regards with how to weld the studs back on with minimal equipment.

Genius!

Make sure to polish the aluminum first to get rid of the oxidation.

If it's not enough juice, just put your remaining packs in series and presto! You got a nice little dc welding setup.

You only need about 18 volts.
 
Checkthisout said:
My take is that, when you win your cc dispute, you're going to get your money back AND be able to keep the cells.

You literally just came up with the solution in regards with how to weld the studs back on with minimal equipment.

Genius!

Make sure to polish the aluminum first to get rid of the oxidation.
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Someone posted above that these don't look like laser welds and I agree , I looked at some images and those claiming laser welds indeed have continuous melted deformation around the perimeter. Mine don't.
And I have also found somewhere that aluminum doesn't spot weld
Then this failure make sense.

As for "genius," I don't have any expectations of that kind. I could maybe agree to a substantial discount to keep and fix but I can't list the number of projects I have. I just need this to work. It was supposed to be a quick detour from other things just to scratch the old "my solar panels don't work if the grid is down" itch.
 
Checkthisout said:
How do they keep cells that large cool/warm?

I'm googling like crazy and can't find any model 3 battery pack photos that show these cells.

I'll keep looking.
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Sandy Munro shows some shots of the Tesla Model 3 SR with CATL LFP pack in this video. All Model 3 and Y SRs sold in China and Europe use this battery and some/all of the US 3 SRs use it (no Y SR sold in the US currently).

I don't know of any other LFP EVs sold in the US yet. Patent issues kept them out until very recently. And the US Inflation Augmentation Act will mostly keep LFP out until some US factories get built. Many EVs sold in the US use large prismatic cells that look kinda like these, but they're all NMC. Tesla, Lucid and Rivian are the only companies I know that use thousands of small cylindrical cells in their packs.

BYD's Blade LFP battery is much more elegant than this clunky Tesla/CATL pack. Blade is a big reason why they've taken over the #1 spot in global EV sales.

EDIT - you asked about cooling. Packs with large prismatic LFP tend to be in low-mid power vehicles. Say 60 kWh pack and 100-200 kW motor. We're not talking about Porsche Taycan or Model S Plaid cooling loads here. Packs tend to have passive plates in between rows of cells linking to active cooling (usually liquid) below the pack.
 
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dielectric said:
Received the batteries about 2 weeks ago and only got the tester 2 days ago.
Out of 16 cells so far I've managed to test 3 and 4th is still discharging.
While hooking them up to the tester 4 cells lost 1 stud each.
They just pop off like it's all fun and games.
I am using a basic torque wrench and after the 1st one came off I watch the needle very carefully, they fall off just after 3nm.
From different sources the torque limit is either 4 or 10nm, either way they don't hold up.
The cells are new QRs intact all tested have 283 or 284Ah, so good cells except a little detached... aloof?
I have emailed the seller, no response after 24 hrs. Will be calling them tomorrow. There were promises of 30day money back etc.
Any advice?
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This happened because the seller contracted a company with a low watt fiber laser. I know of a guy that uses a fiber laser for making custom exhaust pipes, actually he did work for one of the builds on Gas Monkey Garage. If you are near Garland TX he can probably properly laser weld these on to the cell for you.

You need a 2000 watt fiber laser cnc machine to reattach these. They are laser welded. Search for fiber laser welding in your area you can probably find someone.

that being said, be prepared to pay out the @$$ though...
 
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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9/10 times the CC company will tell you to ship the cells back to the seller.... have fun learned this the hard way when I bought a creality printer directly form the manufacturers website vs amazon.
 
Alkaline said:
This happened because the seller contracted a company with a low watt fiber laser. I know of a guy that uses a fiber laser for making custom exhaust pipes, actually he did work for one of the builds on Gas Monkey Garage. If you are near Garland TX he can probably properly laser weld these on to the cell for you.

You need a 2000 watt fiber laser cnc machine to reattach these. They are laser welded. Search for fiber laser welding in your area you can probably find someone.

that being said, be prepared to pay out the @$$ though...
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How would they have welded underneath that collar with a laser welder?
 
Checkthisout said:
How do they keep cells that large cool/warm?

I'm googling like crazy and can't find any model 3 battery pack photos that show these cells.

I'll keep looking.
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they are infact using catl prismatic cells, but they are the same
Doggydogworld said:
Sandy Munro shows some shots of the Tesla Model 3 SR with CATL LFP pack in this video. All Model 3 and Y SRs sold in China and Europe use this battery and some/all of the US 3 SRs use it (no Y SR sold in the US currently).

I don't know of any other LFP EVs sold in the US yet. Patent issues kept them out until very recently. And the US Inflation Augmentation Act will mostly keep LFP out until some US factories get built. Many EVs sold in the US use large prismatic cells that look kinda like these, but they're all NMC. Tesla, Lucid and Rivian are the only companies I know that use thousands of small cylindrical cells in their packs.

BYD's Blade LFP battery is much more elegant than this clunky Tesla/CATL pack. Blade is a big reason why they've taken over the #1 spot in global EV sales.
Click to expand...
ford is in serious talks with catl too, not sure if tha materialized already
 
I would *think* the terminal welding is done by whoever the manufacturer sells the batteries to which in this case is just some fly by night outfit that is setup to ship and take credit card info.

They buy the cells and have found that without terminals, they either can't sell the cells ? or they have to sell them for a lot less than the price it takes to SPOT WELD some studs onto the things.

Even battleborn (premium price) isn't laser welding.

Does anyone have any personal examples of cells they purchased where the studs were laser welded on?
 
Checkthisout said:
I would *think* the terminal welding is done by whoever the manufacturer sells the batteries to which in this case is just some fly by night outfit that is setup to ship and take credit card info.

They buy the cells and have found that without terminals, they either can't sell the cells ? or they have to sell them for a lot less than the price it takes to SPOT WELD some studs onto the things.

Even battleborn (premium price) isn't laser welding.

Does anyone have any personal examples of cells they purchased where the studs were laser welded on?
Click to expand...
 

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