8 EVE cells from Luyuan

[Don B. Cilly]

I just got my 8 280Ah cells from Shenzhen Luyuan (Amy Wan). Grade A-.
They took 83 days from order to door. And the parcel people made a mess so I had to go and pick them up (60 km. from here) twice.
But, apart from that, I'm really quite happy... so far.

The packing was really good. Made to withstand UPS (Uganda Parcel Service) Standards of Destruction.



Not a scratch, not a dent, no swelling, no leaks. The QR code shows Jan '22 as date of manufacture.
Voltages are all at exactly 3.282V (on the same voltmeter).



I'll report on assembly.
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[Don B. Cilly]

Balancing done. BMSsing around... :·)


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[Don B. Cilly]

Almost there :·)
Thing is, I can't find a way to keep that display on for more then a few seconds :·/
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[Bud Martin]

Wow! very well packed indeed with internal corner supports.

 

[Don B. Cilly]

Yes, I quite like the milk crate, actually. Not pretty, but well ventilated :·)
And the size is... just right. I think I'll keep it.

Oh, you meant the shipping packing. Yes, I was impressed. They could fall off the lorry and still be in good shape :·)
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[brb58]

I ordered 10 cells for my 2 4 cell batteries to have a couple spares in case things go wrong down the road. Takes too long to get these to take the chance other wise.

 

[Don B. Cilly]

Now, cell #6.

If I measure it with my own voltmeters, it shows the same voltage as the others (3.282).
But then, #6 is the only on with noticeably higher "wire resistance". What is it? Google isn't much help... the little BMS wire?
I checked it, and the connection seems perfect...
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[Bud Martin]

You may want to check your connection and wiring on cell #6.

 

[Don B. Cilly]

I did... like ten times... so it does mean the little BMS wire?
Oh well. It's 1AM here, I'd better leave it till tomorrow :·)
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[rhino]

I did... like ten times... so it does mean the little BMS wire?
Oh well. It's 1AM here, I'd better leave it till tomorrow :·)
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Yes, the BMS wire.. it's indicating something is "different" with that particular one.

 

[rhino]

Maybe even cut the current ring terminal off you added to it and put new one on. Might have bad connection within connector you added.

 

[Bud Martin]

You can also swap the cell location to see if the problem follow or not.

 

[Don B. Cilly]

I found it. The wire somehow got slightly pinched during assembly, I spliced it.
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[Don B. Cilly]

Everything seems to be working rather well.... for the moment anyway. I'm quite pleased.
One thing I really don't understand: the little display I got ($13). It's got a turn-on/off button, which is good, but,
the brochure states: "When BMS is on, the display will turn off [the LCD backlight] to reduce power consumption if no current output from BMS is detected for 10 seconds" (which is the case).
So I can't see the display (from my chair) unless the battery is discharging. If it's charging, it goes off.
I guess that is a Chinese programmer's idea of reducing power consumption
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[Ellcon123]

Think of it another way. If the display is off then nothing is happening so that is still informative.

Not sure if you have tested it but they may mean current flow in any direction through the BMS. Always a bit of guesswork with Chinese to English instructions. So basically if the BMS is idle then turn off display. Makes sense even if it can be inconvenient.

 

[Don B. Cilly]

I have tested it. Charging at 20A, it goes off. Discharging at 2A (now), it stays on. Plain silly.

[EDIT] It's OK, I'll just keep it as an on-off button and put some plain SOC indicator there. Just for the fun of it, I don't really need it.
It is quite good-looking though. Pity.

 

[Don B. Cilly]

I seem to have a runaway cell :·/

It was #8, I swapped it with #7, it's the cell, not the position.
I guess the only solution is to change it, right?
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[Bud Martin]

But #7 and #8 did not show problem in your post #7. So the problem shows up now as you start charging?

 

[Don B. Cilly]

Yes. It starts when SOC is ~98% (some 27V).
Now, #8 is where the (whole battery) positive is, so I thought, hey maybe... but switching the cell shows the same cell overcharging, in a different place.
It goes to 3.7+V very quickly after that, and takes ages to balance down after charge is interrupted by the BMS.
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[DJSmiley]

While still building, get rid of that automatic breaker

90% of them cause issues when running slightly more current (heat, random tripping and so on)