Identify chip on 2S BMS / Balance card
PAY is Seiko S-8242AAY-M6T2GZ battery protection IC. The last letter G is related to lot number.

Here is PDF (see table on page 23 for part code): http://img.hqew.com/file/Others/1090000-1099999/1098111/Electronic/201251816354378771.pdf

And there is the list of codes, which contains PAY: http://www.dl7avf.info/charts/smdcode/cpa.html#TOC