Here's my adventure trying to revive my drowned iPhone. Fellow battery geeks, please read and help me out a bit...
My iPhone took a dunk two days ago. Water seeped inside and did some damage. At first, the touchscreen didn't work reliably (pressing it would sometimes click, sometimes do nothing). There was a lovely mottled design across the screen itself, which made the screen overall much darker, even though some areas were much brighter than they should have been. The volume buttons worked, the home button worked, but the silencer button didn't, and the power button was shorted so that it was constantly being activated, which meant I could not turn off the phone, as it would constantly turn itself on again. I buried it in a bucket of rice and left it for a day.
After a day of freedom
not having a phone, I dug my iPhone out of the rice. It was in no better condition than it was. I could have kept it in the rice for longer, but I figured that charging it might heat it up and force the moisture to evaporate out of the phone. I hooked it up to my desktop's USB port and left it there overnight.
When I woke up this morning the phone was still not charged at all. I concluded that the constant turning-on that the phone endured due to the stuck power button must have undervolted the battery to the point where it was essentially dead. To revive it I'd need more amps, so I hooked it up in my car on the way to work. Happily, the phone charged to 20% in just about 40 minutes. It got very hot, though.
Now that the phone was charged a bit I hooked it up to my desktop at work. Eight hours later, the phone was just around 50% charge. On the ride home I plugged it into the car again. It charged up to 60%, where it changed to the 'plug' icon, indicating full charge, when it clearly was at 60%. I talked on the phone for a few minutes and dropped about 10% battery capacity.
Then I plugged it in again in the car and it charged past 60%, but took over an hour to get up to 100%. At 100%, a <10 minute phone conversation took 7% battery life from the phone.
The iPhone still gets amazingly hot. Not too hot to touch, but still way too hot. The power button stopped being constantly in a depressed state, but it works unreliably. The silencer button goes through periods, sometimes several minutes long, when it thinks it is being activated and deactivated. Sometimes it'll do it, sometimes it won't, but it's nerve wracking to have the thing sitting on my desk or in the car just randomly vibrating.
I imagine it's dangerous to use, as the heat probably indicates that the battery is going to melt or explode, but at least it works. I'm going to have trouble rounding up $600 for a replacement. Either way, I'm glad I was able to get it to work, at least for a little while longer.