Why no high end battery powered wireless speaker systems?

Veloce Audio makes or at least used to make an upscale "Lithio" series  rechargeable battery powered amp and preamp. They were fantastic with YG Carmels. Their price has since bombed on the used market. I would love to own them but afraid they would be boat anchors pending battery replacement availability. 

Thanks @nonoise for the link. That is the essence of what i am looking for but in a consumer friendly package.  It would be great to eliminate all the cables and expense if possible.  @erik_squires , I was thinking along the lines of having an integrated high power rechargeable battery to power the speakers-like the 7.5 AH ones that routinely come with battery powered chain saws and leaf blowers.  I think a high efficiency speaker is only going to use around 1 watt of power most of the time and maybe 100 watts at high decibel peaks?  If those batteries will power an electric chainsaw or leaf blower for extended periods, I would think a speaker would be no problem.  

Yeah, you have much to learn, grasshopper. To get power (watts) you need amps, and (pop quiz) what else? 

SONOS makes a decent sounding battery powered (rechargeable) speaker.  While I would not use them for serious listening, they certainly sound good enough for background listening.

@millercarbon-oh wise one. If the speaker draws 100 watts, a 56volt 10ah rechargeable battery should run the speaker for: 100/56=1.786 amps per hour.   So a  10ah battery divided by 1.786= 5.59 hours of max run time. of course I could solve the problem by getting a Tesla powerwall and run the whole stereo and house with that.