How do I extend the life of my s3?

[ld5596]

I have been using my samsung galaxy s3 since 2013. I rooted it in 2015. I changed my phone but continued using both the phones. Now, I want to use the s3 only, again. I am a tech illiterate, so please help.

What I am ready to do-
-Download anything provided I have enough information

What I am not ready to do-
-Pay, anything!!

What are my current problems with the s3-
-*Most Important* CHARGING BATTERY!! I have tried different chargers, I have bought a new battery(terrible waste of money). My battery drains a bit too quickly for my liking, much quicker than the s3 used to earlier. But the more annoying part is charging. I have installed this app called Galaxy Charging Current, and it gives me 100mA almost all the time (Reference: 999mA). I adjust remove the charger and plug it in again, it shows 500mA or so. Its basically 200mA on an average and becomes 100mA very easily. 100mA btw is when it isn't charging at all, I never see an increase in battery percentage. I charge my phone the enitre night only to 'increase' it from 3% to 3%!
-I have no clue how to use greenify
-RAM! I have 800mb of usable ram, and that gets filled up really quickly What can I do to stop unnecessary apps from running but I need few apps (such as my official college app which gives notifications almost everyday)
-Lag- while playing a game. I guess improving ram will make this alright
-A power button that is stuck, I can use it with my nails, but its almost on its deathbed
-Yeah that's it I guess

My s3 still looks beautiful, at most I can pay for the power button. I really want to use it forever!! Please tell me how to overcome these problems.

Also, the battery problem exists for different custom roms, and after wiping cache and even after factory reset. Its really moody, its 1000mA when I am really lucky, for its entire charge.

*Also, I know it isn't healthy, but I want to use my phone while charging*

 

[Rukbat]

I have installed this app called Galaxy Charging Current, and it gives me 100mA almost all the time (Reference: 999mA). I adjust remove the charger and plug it in again, it shows 500mA or so. Its basically 200mA on an average and becomes 100mA very easily. 100mA btw is when it isn't charging at all, I never see an increase in battery percentage. I charge my phone the enitre night only to 'increase' it from 3% to 3%!

Those are signs of a pretty dead battery. If you're not willing to spend $6 or $7 for a new one, you probably can't fix the problem (but see the next to last paragraph of my answer).

-I have no clue how to use greenify

Run it. (You'll need Xposed Framework for it to run to full advantage.) It pretty much runs itself on a rooted phone.

-RAM! I have 800mb of usable ram, and that gets filled up really quickly What can I do to stop unnecessary apps from running but I need few apps (such as my official college app which gives notifications almost everyday)

RAM or storage? Android is supposed to run with as much RAM filled as possible. Storage? Move files (not apps) to an SD card.

-Lag- while playing a game. I guess improving ram will make this alright

No, actually, unless you can find 3 or 4 year old games, nothing will make it right. Games written today need faster phones. Games written in 4 years won't run on today's flagship phones.

-A power button that is stuck, I can use it with my nails, but its almost on its deathbed
-Yeah that's it I guess

I don't recommend taking a phone apart, but this one is going to cost a few bucks. Not that much - the button is a few cents, but the labor is going to cost something.

I really want to use it forever!! Please tell me how to overcome these problems.

I really want to use my Note 3 forever too. My LG G5 is scheduled to arrive today. You can use an older phone for some things, but after a while, if you don't sell it while it's usable, it's worthless. (Anyone want to buy an old Samsung Precedent? Swappa has one listed as having sold recently - for almost nothing.)

Also, the battery problem exists for different custom roms, and after wiping cache and even after factory reset. Its really moody, its 1000mA when I am really lucky, for its entire charge.

As I said, it's probably a bad battery. But try this first. Remove the battery. Wipe the contacts on it vigorously with a clean cloth. Sometimes oxide buildup on the contacts can cause it to be intermittent like that.

*Also, I know it isn't healthy, but I want to use my phone while charging*

Nothing wrong with that, as long as the battery is actually charging while you're using it. It might take hours to fully charge it (even from 40%, which is as low as you should let the battery ever go), but it's not harmful to the battery to be charged very slowly.

 

[ld5596]

-I have used a new battery, similar problem. It does charge sometimes though. As I said, it is very moody. I think its a problem with the port. Because I have tried multiple batteries and multiple chargers.
-I will figure out how to use greenify later. I know this sounds ridiculous, but I dont know Xposed well enough yet
-Storage is not a problem. I keep almost everything on the sd card. It is the ram! The phone suddenly stops working because too many apps are consuming memory. I don't want unnecessary apps to run
-I dont mind the games lagging
-I need tips on how to continue using the phone, I dont want it dead.

 

[Dustin C]

I just retired my s3 about 3 months ago! The only problem I had was a worn out charging port. I fixed this issue by buying a wireless charging kit. Hope this helps!