Bose mini soundlink flashing red light

So my Mini II ran out of charge and I tried to charge it up. It's just displaying a flashing red light when charging and not turning on or anything. Doing an internal (holding the MFB then pulling out the charger) or factory reset (same with power) don't work because when I unplug it it dies instantly. It's my usual charger that I use for my phone and it's working fine, I've even tried other cables, there's no firmware updates needed, I am completely and utterly stumped. What's strange is when I try to do an internal reset, the rest of the lights including the orange battery come on while I hold it but as soon as I pull the plug they go out completely which is not meant to happen and the updater does recognise that the speaker is plugged into my pc. It's as if the battery isn't charging and the cable is just powering the lights. Is the battery just completely dead?