How can I get my Nokia Lumia 930 to turn on?

[Windows Central Question]

Yesterday, I was in the car and I had my Nokia Lumia 930 plugged into my portable charger and the phone said about 'Slow Charging' but it usually does with that charger so I thought nothing of it.
It stayed on 2% for ages and stupidly I continued using the phone, it didn't heat up or anything and it claimed it was charging and suddenly the phone went off without warning.
When I got home I plugged it into my main charger and it didn't respond at all after being charged for 2 hours. I put it onto my wireless charger and the white light turned on (I'm assuming it means that it detects a device to charge).
After a while more of charging and holding the 'Volume Down' button it vibrated and the 'Home' Button flashed (indicating very low power) but nothing after another hour and the flashing stopped. Oddly enough the camera flash went off a couple of times after messing around with it a bit.
I charged it overnight in a warm room with no effect, the soft reset doesn't work and I don't wish to attempt hard reset as I fear I'll lose everything on it including important photos.
Somebody help

 

[RumoredNow]

Every interruption of the process... Pressing buttons, switching chargers... It all makes you start over again from scratch. And potentially could be causing damage.

When a Lumia shuts down due to a flat battery the chip in the battery goes into a coma. The Factory AC charger is the recommended cure and you must have patience. It might take several hours. 4 or 5 hours even. Be patient. If it doesn't come on after 8 hours something is wrong inside. If it does come on it will boot and still have a very low battery percent, even being on the charger for so many hours. But of it does wake from the coma it will start charging normally from that point. Let it get to 100%.