EVE 230 Ah Cell Measurements

[justgary]

I received my 36 EVE 320 Ah cells from China last Friday. As I unboxed them, I inspected them, weighed them (because @ghostwriter66 said she does), and measured the resting voltage on each cell. For some reason, I decided to also measure from the positive pole to the cell case (through the little "+" and "-" cutouts in the black cover). I expected to see that all the positive poles are connected to the cases, but fifteen of the cells have less than the cell voltage when measured that way. A few of the cells acted like the case was connected more like a capacitor since the voltages seemed to float a bit. I did not attempt to draw current from the cell that way (positive to case) because I am sure they are not built for that.

Have any of you measured your cells that way, and if so, did you get similar results? Can any of you explain how the positive poles are connected to the cases? Curiosity killed the cat, but satisfaction brought it back, you know.

My data (sorted by order of manufacture) is attached as a PDF.

 

[ThomasSun]

Why are you interested about this? This affect the battery selfdischarge , insulation problem and the leakage risks, different battery cell company has its own standard.

 

[justgary]

Why are you interested about this? This affect the battery selfdischarge , insulation problem and the leakage risks, different battery cell company has its own standard.

I'm a little confused by your answer. I'm interested because I measured it and expected all of them to be similar. All of the cells are brand new EVE 230Ah made within three days of each other, not different brands.

 

[SveinHa]

I did also measure on my EVE 230Ah cells and found that the + pole on almost all cells seems to be connected to the case. I had some kind of short circuit that I assume is between the case of 2 of the cells. I couldn't find any hot marks on any of the cases but some flames and smoke appeared between the + pole on cell 16 and top cover.