[Galaxy S III General] d4fseeker:
Sorry to say but that really doesn't look like a battery problem, more like the hardware itself blew!

Here are the best pics of the damaged phones:

http://www.boards.ie/vbulletin/showpost.php?p=79312161&postcount=15

You'll see that the battery is intact and far away from the blackened region.

Now take a look at the logic board layout:

http://guide-images.ifixit.net/igi/qneCB1ZDEXXKkcum.large

http://guide-images.ifixit.net/igi/iSxZ1SQMJAKAnXZo.large

The first logicboard-picture shows the phone from front, the latter from behind.

(Easily identifyable by the telltale USB-plug and battery connectors)

According to the pictures of the damaged phone it's on the left side of the USB-plug when looking at the phone from behind (or the right side from front).

On the front we got in that direction:

- CYAN: Intel Wireless PMB9811X Gold Baseband processor

- ORANGE: Samsung Exynos 4412 quad-core A9 processor with 1 GB LP DDR2

On the back we got in that direction:

- ORANGE: Skyworks SKY77604 Multi-Band Power amplifier

- BLUE: Silicon Image 9244 low-power MHL Transmitter

- CYAN: NXP PN544 NFC Chip.

I don't think the MHL or NFC chips were in active usage, so the most likely candidates are:

- ORANGE: Skyworks SKY77604 Multi-Band Power amplifier

- ORANGE: Samsung Exynos 4412 quad-core A9 processor with 1 GB LP DDR2

Since the Skyworks is positioned nearly behind the USB plug and it _looks_ like the origin is more to the side, I'd wager a guess that the Exynos has blown.

After re-reading the forum post which states that the device still works but has no reception I believe it's the Skyworks amplifier which blew. It certainly has the high-frequency, power output and periphery which could lead to such a desaster. The rest of the psot still applies

If that's true; had the user overclocked his device and played around with CPU/GPU voltages? (That can easily cause it to abruptly overheat and die, but I'm not sure that it would show to such an extend)

It looks more like the core or glue/plastic burst into flames from high temperature either due to a manufacturing fault, overclocking or keeping the phone with enabled GPS navigation in a car under direct sunlight and no air conditioning.

I've had several electronical devices (thermometers,...) melt on me when leaving them under the windshield while keeping the car parked in the summer. So even if the device powered itself off when overheating, a possible scenario is the owner getting back in the car, noticing that the phone is turned off and turning it on. The overheat protection does not kick in (maybe because it takes some time to initialize or maybe the phone was already damaged from the heat) and the core immediatly reaches temperatures far beyond his specification. Boom...

[Edit]

While capacitor failure _may_ look like this (I've seen my fair share in power supplies and on motherboard CPU power-converters) there are no capacitors in the mobile with a sufficiently large capacity and hardware size for such an intense blow-up.

[Edit2]

Re-Read forum post of the linked thread. The device is still functional but no reception, so it's not the CPU. (Thanks to my girlfriend for pointing it out)