Is there any quick way to tell the condition of an iPhone's battery, i.e., how many cycles it's been through, what charge it can hold, etc. The info on the device itself is not too useful in this regard Backstory: I have two White 3G iphones. I bought them off of craigslist. Both had been used for about 3 days, and both appear to be in perfect condition -- there's no cosmetic reason to prefer one over the other. I'm now going to sell one of them, and I've seen the threads where some people have a defective battery. If there's any difference, I'd like to keep the one with the better battery.