I have an iPhone 3GS, just inherited from my brother, I say this as it's new to me, seems to consume its battery even when off. I can switch all functions off, charge it to 100% leave it overnight and it has discharged by 40% by the morning. It seems to be even worse with the SIM card in. Vodafone PAYG. The SIM is over 3years old. The battery is now 2+ years old, could it be that it needs replacing or is this just normal.
Any advice would be appreciated.
What about this?
It is a portable backup power supply unit, with USB interface. It is suitable iPhone 3G, iPhone 4G and a variety of iPad digital products.
Using high-capacity lithium battery. It ensures the power supply / charger to consoles for long time.
With sleep mode and low power switches reminder. Intelligent power save energy.
Large-Capacity USB External Backup Battery Pack Power Supply for iPhone 3G/4G
Ugh. What a crummy problem. If it was me, I would get to an apple store or call their customer care to see about what options are available... That, or get one of those portable charges, and keep it charging all of the time. Good luck! :(
Thanks everyone for your views and opinions. I have been trying some further tests. If I switch the phone completely off-press and hold off button and slide. Then the battery holds charge overnight, only losing 1 or 2% of capacity. I think this means the battery os OK. When the phone is in standby with all functions switched off, it is still consuming battery. To me, this means something is operating in the background and I cannot find out what it is.
For the cost, after two years plus of use I am tempted to have the battery changed anyway. I will give it some more thought and report back.
Thanks again to all who posted.
The batteries begin to decline in performance after about a couple of years. They prefer being topped up, not being run down to zero and being charged up again. Though Apple's battery care page suggests that it's worth running down the battery once a month.
In the meantime, there are free battery monitoring apps available, you could use them to track battery usage. Also turn off non essential services such as Bluetooth, push email and so on. Turn the screen brightness a bit lower.
This should get you a bit more time until you trace the fault itself.