As title states.

The phone just died last night while I was using it, and right now if I charge it, all I see is a solid red light on the LED. I've left it to charge for an entire night.

After looking around for a bit, I've also tried the whole Volume Down Power button, then connect to USB charger method to get the bootloader to run, but that hasn't worked for me as well. I'm at a loss of what to do. Any suggestions?

In the case it cannot be salvaged, is there any way for me to transfer all my phone data to another device at the moment? I am thinking of buying a Nexus 6 anyway, and I'd like to maintain data such as app data, contact book, etc.

UPDATE: I've sent it in to a mobile repair shop, and was told that other than the battery there also appears to be a motherboard issue. I am hoping this will be enough to fix it.

UPDATE 2: It is now fixed!