Why is my Galaxy S3 dying really fast?

[TheRadGamerDan]

Galaxy S3 dying really fast, Cell Standby using 50% battery

Hey! So I just brought a new battery for my Galaxy S3 i9305, 3.8v 3800mAh and my battery dies pretty fast (same happened with my old battery), so if my phone is at 100% when I go to bed, when I wake up it'll be at around 50% and idk what's wasting the battery so much, when I go to bed I close all open applications and things, but that makes no difference. When I checked the battery, I saw that Cell Standby was using 56% of my battery? When I click cell standby, it says Time Without Signal 100% because I don't have a simcard in my phone. I have tried turning on Airplane mode, but that makes no difference at all to the cell standby. I am also using a custom rom, Codename Lungo rom. Is there any way to completely disable this cell standby thing?

 

[Orlan2]

Re: Galaxy S3 dying really fast, Cell Standby using 50% battery

As I can tell by your screenshots you aren't on stock ROM, so I would highly suggest you verify the logs and bugs for the ROM you are currently using there might be a Battery related bug or and excessive drain in the way the kernel on the ROM is handling the Power coming from the battery, so I suggest to try back on a stock ROM to see if the problems persists.