Advise on cells

[Partsjockey]

I purchased 16 cells from Docan Power through Amy in May of this year received them end of June I believe. Have tested all 16 I have 4 that are defective ( 2 really blotted and 2 others that are blotted but one bleu the vent and the second one wasn't far behind. I had to bring these 2 cells up to 3.50 to put in my 12v pack to test. I used a small variable 30 volt & variable 10 amp power supply that you buy on amazon, so that as the amps come up in the cell the amps go down on the machine till finally it stops. It took some time just to bring the buggers up. Anyways I double check just to make sure the power supply was working properly and it is. Any clues as to why just these 4 turned out that way? Any help would be great.