Cubexx wont turn back on after charging?

So I powered the unit off so I could fully charge it before flying out for a trip but now it won’t turn on at all? I already had issues where I had to reflash the microSD straight out of the box.

Ive tried reflashing the firmware to a newer microSD with no luck. I’m going to try and unplug the battery on the motherboard, but if that doesn’t work I’m really at a loss.