Thanks man! My wifi problems disappeared after removing the battery. Amazing solution but it works.

I opened it up and saw that the battery BAT500 has leaked.
I have had no WIFI issues.

I will try to remove the battery tomorrow and see if it helps.
It is good to know the that phone can work without the battery installed.
I hope there is no permanent damage.

I just hope to get it turned on so I can retrieve all the data from the internal memory and then maybe buy a new phone.

Thanks for sharing your experience, my man!

I had the same problem with my Galaxy S2 (727 AT&T USA version). I has same BAT500 near wifi chip just like international and other versions.
Problem:
My wife would connect sometimes and after a few hours, I see that it is “trying to turn on” but not successful. After a while, the semi-green wifi button become grey. I didn’t think it was a software related problem. I was pretty sure it was hardware related. Based on this post and other posts, I looked inside and the BAT500 (battery/capacitor) looked just fine. There was no acid leak or anything. But the problems with these capacitors is that they can short inside, and still look good from outside. Anyways, I decided to take it out. I just used a screw drive I used to open the phone, took out the BAT500, infact, broke the metal contacts around it. Now, in my phone, I don’t have BAT500 at all. I don’t think it’s really needed b/c as soon as the phone boots up, the time/data is synced via Air by AT&T. In any case, I didn’t feel any difference. Wifi started working. It’s working since then without any issues. I still need to understand the function of the BAT500 a little better. But for now, I am happy that wifi is working fine.

As always, do it at your own risk 🙂 Be very careful when trying to rip apart the BAT500 from motherboard. Just one slip of the screw drive (or whatever tool you are using) can damage the mother board. But in reality, it’s a pretty easy job.

Glad you find it useful. Thank you to everyone who posted their input here too!