If you are having problems with your iPhone maintaining power or even powering on it may be time to buy iPhone battery online at an iPhone website. To buy iPhone battery online is simple. You just find an iPhone website that you like and find the proper battery for your iPhone and then buy iPhone battery on that website. If you are going to replace that iPhone battery yourself you should also consider purchasing an iPhone battery replacement kit online also.
When you decide to replace the iPhone battery yourself you will need a couple of items that may not be lurking in your tool box at home. Because the iPhone is rather small you will need some rather small screwdrivers Phillips head, flat head or both. If you have the iPhone 4 you may need an iPhone 4 5-point screwdriver which is made for the iPhone 4 if it has the Pentalobe screws that Apple has used to replace the normal Phillips head shaped screws. If you dont know what a pentalobe screw is perhaps you really need to send in your iPhone to get the battery replaced and pay someone else for the battery and the replacement of it in your iPhone.
You can also arrange to get your iPhone repaired on the iPhone repair website. This does not have to be the Apple site but instead a third party site that specializes in the repair of iPhones. When you find an iPhone repair site you like you should bookmark it so you can easily find it again if you have to. They make it simple to buy a new iPhone battery and they will perform the repair for you too and get the phone back to you quickly. When you do this you have to remove the SIM card and make sure you include any unlocking passwords too.
If you send it back to Apple to buy a new iPhone battery you will not see your unit back for at least three business days. If your iPhone is less than a year old Apple may replace the battery so long as you didnt damage it yourself. If you choose to send it to Apple you may be able to drop it off at your Apple retail site so they can ship it back for you. If you dropped the iPhone or sent it previously to an unauthorized repair site then Apple will not cover the repair. If you perform your own repair tasks on it Apple will not repair it under its warranty. Also if you send it to Apple make sure you back it up because it will be returned to you data free.
Another option is to take it into a local iPhone repair shop. It may be a repair shop that specializes in Apple products or a general phone repair shop. There are a lot of local small business owners that have shops where they perform repairs as needed on cell phones including the iPhone.