iPhone 3G shuts down when not plugged in

It is not supported and is extremely difficult and very risky to revert back to a previous iOS version. Try taking it to your local genius bar because it is probably hardware, although you could try restoring if you want to try something before making a trip over.

-SM

My 3G's problems have only gotten worse with each new update. Now I literally can't use it continuously for more than two minutes without a full charge going down to zero. I can basically just call people on my 3G and that's it. I probably need to get a new phone now, but with the iPhone 5 possibly coming out this year I want to see if the iPhone 4 (and iPad 1) will go through the same ordeal with iOS5.

I think Apple just needs to learn how to make their software more scalable and learn to support different versions of their OS simultaneously.

With so many models in use it's almost become the same as their personal computers. They shouldn't continue to just support one updated OS optimized for one specific model. Microsoft continues to update and support Windows at least one generation back from the current version because they know there are people who are going to own these things for four years at a time.

RedSwirl wrote:
Now I literally can't use it continuously for more than two minutes without a full charge going down to zero.

If this is really the case - that after 120 seconds after unplugging it your batter goes from 100% to 0% - then you surely have defective hardware. +That's a drop of nearly 1% every second!!+