Why is my iPhone battery dying so fast?

I just bought an unopened iPhone 4S, because I prefer the smaller phones, and the battery drains in less than 5 hours. The phone was never used before, but is the age of the phone the reason it's dying so fast?

Will replacing the battery make a difference? As those are old as well even if I but an unopened one.

Added (1). bought*

Added (2). My previous iPhone 4S is just as old, but was used constantly. And that has much better battery. Lasted two days, even if being used a lot.

What do I do with my broken iphone 6?

I dropped my phone and cracked my screen. I don't think I have apple warranty/insurance, so i took it for a repair at this other place since they fixed y ipad before. Anyways, they replaced the screen and everything was fine. A couple of days go by and my phone blacks out and my screen is just black and unresponsive. I tried everything to get it to work. I took it to another place and they said the motherboard was broken or something, they tried replacing parts but couldnt fix my phone. It doesn't turn on I still have a black screen. What can I do? Should I go to apple and see what they can do? I need suggestions

How much does it cost to fix the touch ID on my iPhone 6?

How much does it cost to fix the touch ID on my iPhone 6? - 1

Added (1). Touch ID not responding to taps or finger print recognition. Wondering if anyone else has taken it to the apple store and paid to get it fix. I don't have warranty on my phone.

Space grey or rose gold iPhone 6s?

I'll probably be getting one in a few months… Which color should I get? Personally I think black iPhones look more sleek and nice but the rose gold seems more new… Or should I go for silver or regualr gold? (I don't really like those 2 btw)

Iphone showing notifications on lock screen?

I have an iphone 6 and when i'm on the lock screen (as in before putting in a passcode) i can swipe from the top of the screen to the bottom and see all of my notifications. Can i turn this function off?
ta.

Am i the only one that will pass on the iphone 6s?

I have a iphone 5s and i love it. Am i the only one that is not wowed by the 6s. It looks exactly the same as the 6 and the only new feature is the force touch which i think is kinda stupid. I know that i will never use it lol. So i want to know what you guy's think of the iphone 6s

Iphone 4 bypass without SIM Card?

Iphone 4 bypass without SIM Card?

Added (1). I got an iPhone 4 with no SIM card and I need to bypass the lock screen. What command should I tell Siri so I can get in the phone since there's no Sim Card?

How to drain a iPhone battery faster?

Basically IIm tryna drain my iPhone battery till it's dead so i can give it a full 0 to 100 charge tonight, any ideas on what apps are the most battery intensive or anything that could help? Already running every single app on the phone, flash light is on, brightness at full, bluetooth is on.