iPhone 4 battery.

[Alexx..]

Usually my iPhone 4 battery is good, I go to college, listen to some music and when I come home my battery is still on like 95-ish percent. But now, my battery is absolutely busted, even if i leave my phone and don't do anything with it, the battery goes WAYYYYYY down, and when I listen to music it goes down like 2% after every song. I haven't done anything to the phone for it to do it, I just do what I usually do, charge it on a night and leave it during the day.

Does anyone know why my batteries suddenly acting all crazy?

[Stephen!]

Do you have WiFi or Bluetooth left on?

[Alexx..]

Do you have WiFi or Bluetooth left on?

My bluetooth is never on, but my WiFi is always on, even before my battery started messing up

[LMS16]

Reinstall the iOS, maybe the software isnt reading the % correctly... If it still does it, your battery is broken :)

Lew.

[.Shaun,,]

Maybe you over charged it, you can always get the battery replaced

Also if you've left it in the cold it can wear your battery out.

[Mark]

This also happens to me, to make the battery last longer let it run down to almost 0% and then give it a full recharge

[Muct]

My bluetooth is never on, but my WiFi is always on, even before my battery started messing up

Turning off WiFi will help this - even when you are not using the internet, WiFi still uses your battery - so when not using I suggest switching to Airplane mode or just switching WiFi off - Airplane mode would save even more though.
Don't know what else would help if it's on sleep - don't think turning the brightness down would help if it's asleep but meh.
Oh, but you could turn off Push Notifications and EQ.

[Stitch]

I've noticed this happening to my 3GS since I first saw this thread. I'm thinking it might just be because I've been paying more attention to my battery level because of this thread. :P

I think you might have over charged it or something. How far does it go down in an hour on standby? When you say "WAYYYYYY down", I'm thinking 10-20% in about 1-2 hours.

[Recursion]

I've noticed this happening to my 3GS since I first saw this thread. I'm thinking it might just be because I've been paying more attention to my battery level because of this thread. :P

I think you might have over charged it or something. How far does it go down in an hour on standby? When you say "WAYYYYYY down", I'm thinking 10-20% in about 1-2 hours.

No.

Smart phone batteries don't last very long, unfortunatly battery technology hasn't kept up with the technologies we need them to power.

Make sure you're closing background apps (double tap the home button, hold down on an icon at the bottom, close the apps with the red - sign), are you jailbroken?

[Alexx..]

I'm not jailbroken yet.

I've left it to die and then i'll recharge it up when it does.