16s 280A for boat drive but cells slightly swollen from Shenzen Basen

[helkatz]

Hello folks
I'm Helmut from Austria!
My project is a 48V 280 AH battery block for an electric boat with 8KW drive
I ordered 280Ah cells from Shenzen Basesn and a JBD BMS, the relay version.
The cells was prompted as Grade-A+ brand new.
Delievery and customer clearance was as promised
A visual check revealed that a few cells are slightly swollen see photos.
Voltages of the cells are all exactly the same 3.295V
Internal resistant are 19 and 20 mOhm
Qr-Code looks good and buildingdate would be from end of 2021 and begin of 2022

I would like to clamp the cells with 300Kgf according to the specification and now I thought with my 16s configuration I have 2 rows so I would make sure that the 2 rows are each equipped with bloated and flat cells so that the package length is the same.

I would be grateful for tips and suggestions HowToDo!

Is this slight flatulence normal?
Pic1 shows the cells staing each next to other
Pic2 shows the pack with sorted cells and compressed
Pic2 shows the QR of one cell, looks that good?

 

[time2roll]

I want to call normal. I would strap them in and put in service.

 

[helkatz]

as i checked the overpressure ventil i have seen that some of them looks not so pretty like others
maybe its normal but i dont know maybe someone can check his cells to confirm
Pic1: looks normal
Pic2: looks a bit expanded
Pic3: normal
Pic4: expanded

what do u think guys

 

[Alkaline]

Hello folks
I'm Helmut from Austria!
My project is a 48V 280 AH battery block for an electric boat with 8KW drive
I ordered 280Ah cells from Shenzen Basesn and a JBD BMS, the relay version.
The cells was prompted as Grade-A+ brand new.
Delievery and customer clearance was as promised
A visual check revealed that a few cells are slightly swollen see photos.
Voltages of the cells are all exactly the same 3.295V
Internal resistant are 19 and 20 mOhm
Qr-Code looks good and buildingdate would be from end of 2021 and begin of 2022

I would like to clamp the cells with 300Kgf according to the specification and now I thought with my 16s configuration I have 2 rows so I would make sure that the 2 rows are each equipped with bloated and flat cells so that the package length is the same.

I would be grateful for tips and suggestions HowToDo!

Is this slight flatulence normal?
Pic1 shows the cells staing each next to other
Pic2 shows the pack with sorted cells and compressed
Pic2 shows the QR of one cell, looks that good?

I have seen cells far worse shape than those, do a capacity/watt hour test.

 

[Ampster]

They look fine to me. I have 52 of them.

 

[helkatz]

so u mean your seals are also not all the same and some looks expanded?

 

[Ampster]

so u mean your seals are also not all the same and some looks expanded?

I mean that my cells were not all exactly the same and there was some small expansion on the long side but my cells have performed well for two years without issues. I do keep them in compression as the manufacturer recommends.

 

[helkatz]

i make less thoughs about the slightly expansion than the seals values maybe u can check your seals as well and tell me there optical condition!

about compression did u realy the 300Kgf or just that they fixed

 

[Ampster]

maybe u can check your seals as well and tell me there optical condition!

There was nothing wrong with my seals but they did vary in appearance.
As far as compression is concerned I used 5/16 inch thread rod and tongued it to ten or fifteen foot lbs of pressure. Nothing scientific, I just did not want any normal expansion to put pressure on my bus bars and distort the cell top terminals. My philosophy has been to not let perfect be the enemy of good.

 

[helkatz]

so i think u have 4 rods per cell block and u torqued each with 10-15 foot lbs thats about 20 Nm
mhh this is a lot of pressure i assume u get much more than 300Kgf
i tried and 10Nm its about 240Kg axial force for one rod!

when u say they seals did vary in appearance.does it mean u see also some they looks like expanded like in my picture?
maybe u can make a picture

 

[Ampster]

They looked very similar to your pictures, or other pictures I have seen. Test them or put them in service.

 

[helkatz]

Yes next day's I will do capacity test and then I will know more

 

[LFP addict]

Basen send me LF280N from 02-2021 where i was promised LF280K with eve report to prove they where A+ grade.
Never got the report. Scam compagny.

 

[helkatz]

Dear customer, I’m Sunny from Basengreen after-sales services department. Please let me know if I can answer any questions or forward your issue to our after-sales services team.

You can also email to info@basengroup.com, we’ll be very happy to help!

Hello Sunny
thanks for your contact the cells i got from basen are all swollen and capacity ranges from 265AH to max 280AH just 1 cell was not swollen and reaches 286AH.
to build a 48V Battery pack from them is the worst because of the celldrift and of course the pack reaches only the 265AH

i ordered by Vicky and i wrote with here a lot but she never forwarded me to the after sales which was my wish

so maybe u can help me with this cells

 

[Alkaline]

Yeah this guy is like going around every where, ok I"ll bite, Alex Chen sold me 8 cells in 2021 claimed they were grade A perfect, When I did capacity test and only got 260 out of 280, I found he no longer works for the company sales and has been promoted.

So Sunny what do you say? Will I get 8 replacement cells?