No Power on Initial Start (Intermittently)

Hey ya'll looking for some help on my 2010 with 150k miles. We've owned this car for about 4 years and 50k miles, never had any issues until about 3 days ago. I went to get in the car and press the power but no power up sequence and no lights on the dash, I did hear a weaker hum than usual, so it seemed like something was happening. I try multiple times, nothing, I start thinking it the 12V battery, having never jumped this one I though I knew it was somewhere in the trunk I tried to go back there but couldn't open the trunk, tried to unlock once the locks sounded weak and moved slow. Tried a second time got in and her the normal hum the car makes, went back to try and start again and boom it fires up without issue.

So I'm testing out what I can for the past two days, and I guess luckily I'm able to replicate the condition. Started reading about the low key fob battery, but holding that close to the power button doesn't work, the indicator light doesn't change color. When the car was in the failed state I was able to climb through the back seat and put a multi-meter up to the 12V battery and got 12.25V. Also the open door indicator will sometimes show and other times not, along with the locks move slow when it's in this condition. Then auto-magically everything starts working like normal. It seems to happen after leaving the car sit for a few hours, although I just had it sitting for about 3/4 hours and it fired up without issue.

I've read through a host of similar problems and am thinking the break switch may be the culprit but this doesn't explain the slow lock movement or inability to unlock the trunk, which sounds more like a battery issue. Is there a chance the battery could be bad but give a good reading? The terminal leads are clean as a whistle.

I took two videos of the situation, the first was the situation being reproduced. As soon as I ended that video the auto-magic started working and the car came back on. I put the meter up to the battery which does show a little low but that was after a couple starts of not letting it charge up.

Any help is greatly appreciated!

 

Thanks @tankyuong, what leads you to that assessment?

 

Looks like it's the battery, found it in the same condition this morning, unable to unlock an no electric hum when opening the door, battery was at 11.6V. I put cables from the other car directly to the battery, measured 14V, started right up. Looks like O'Reilly's is the only shop with a deal, 15% off, so I'll install and update.