Replying to Advice on speakers

Hey guys, i'm pretty clueless when it comes to audio speakers. But i'll tell you what I want and maybe some people will have suggestions.

- Portable -- By this i mean it must have a rechargeable battery, I don't care if its physically small and easy to carry.
- Loud
- Good sound quality at high volume

If it has bluetooth, that's awesome, but aux cords work well too.

Basically just want something that can sit in my back car seat cause my car speakers suck, and something that I can bring camping/use when I don't have a power source. I'd never want to get actual speakers installed in my car cause I hate it and don't want to invest any money in it.

All the speakers I find online are smaller than a case of beer, and I just can't imagine any of them being too loud. My friend brought this ion block rocker to pemberton music fest with us, but the sound quality crapped out at louder volumes.

Suggestions much appreciated. Not sure what my budget is, maybe $400 ish. But cheaper the better