The batteries are not soldered even in the newest Samsung phones. Everything you'd want to replace is modular. Not sure about Apple.
lazyslacker
Dude you can just turn on the "night" mode on whatever device you're using and completely solve your problem. You don't blame the sun for being too bright, you just put on sun glasses.
In my experience, this is intentional. You're watching a thing with full dynamic range sound. Honestly, the intention is for you to have a decent speaker system and to turn it up so you can hear the dialog comfortably. The loud parts will be loud and that is the intent. Why would they make the loud parts quiet? An explosion isn't supposed to be quiet. They shouldn't make it quiet for the sake of you listening to it through your TV's built in speakers at 2 in the morning while the rest of the house is asleep. If you need the dynamic range to be compressed for your purposes you can do that yourself. Many devices have this option these days. My Roku has "leveling" and "night" modes which compress the dynamic range so there's not such a difference between the quiet parts and the loud parts.
The part that no one ever talks about is that a well fitted high quality suit, which is the most ubiquitous professional/ business wear for a man, is just about as comfortable as pajamas. It's like a secret that all men share and don't talk about because if this fact came out widely enough the jig would be up and we might have to dress in something more punishing. Jeans are often more restrictive and uncomfortable than suit pants.