I believe you have some far worse problem than that battery. The lowest led on the front of the board (the red one) is the board fail light. Yours is blinking every few seconds or so in the video. That means your board is resetting and not powering up. If you have a spare board I would go that route first. If you just had a battery problem, the board would boot all the way up and give you the low battery error. In the case of the green varta battery the error you would get is tell-tale battery low. Sure looks like software or board to me.