How to check, my new battery is original or not for Dell Inspiron 17R (7720)

Greetings to ALL

My name is Sergey and I am from Ukraine

I bought battery for my Inspiron 17R (7720).

I would kindly request any DELL Technical Support / Liaison to assist me in knowing the battery which I bought is genuine DELL or NOT ?

This battery has Dell part number Y3PN0 - for this DP/N Google search shows another type of battery. Cells made in Japan but first two letters in serial number are KR, which are mean that cells from Korea. Seller insist that battery is original, but I am not sure, because laptop switching off when has 76% (after 36 minutes of working) - and switching off immediately, without saving any work.

My old battery has DP/N 911MD

Thank you in advance.

BRGDS,

Sergey