…either battery-powered or can be pre-charged
I doubt you’ll find any that carries a self contained battery. Most would be required to be plugged into an outlet such as the KEF LS50. I heard the Cabasse Rialto at audio shows twice and many commented they’re underpriced for the great clear and surprisingly satisfying low end.
After hearing the Vanatoo Transparent One here at AXPONA, I was very surprised how great they sounded at such an inexpensive price- I purchased a pair.