A:AnswerThe battery is a battery pack like a IPad. It is a self contained unit that is not designed to be "swapped" out if your battery goes dead. You could probably replace it but I do not know if a higher capacity battery is available.
A:AnswerYou can upgrade the ram. Im sure it's gonna be effective on FPS for games. And it's gonna effective overall use.
You can get
DDR4 2666(PC-4). Just remember you can put max 32gb. So my advice you can buy another 8gb then you should be good.