Need Assistance - Youngest Son played with battery

Hi,

i need your help, crazy story.

While i was DIY the battery replacement on my Macbook Air, i put down the factory battery on the table. My youngest (autistic) son picked up the factory battery & the iFixIt replacement battery and went to his room before i had time to stop him.

Long story short, now i have 2 batteries, that i have no clue which one is the factory battery & the iFixIt replacement battery .

1 is a NinjaBatt - Model No. A1375 Li-ion Polymer 7.3v - 5200mAh - 38 WH (with 4 cells)

1 is a Model No. A1375 Li-ion Polymer 7.3v - 35 WH (with 6 cells)

If anyone can tell me which is which.... i'd really appreciate it.

Thanks for your help :)