Lots of attempts at battery-powered (BP) combos from different manufacturers. Clearly there is a market for BP amps. I wonder why nobody--perhaps an independent boutique--has made a BP head that can be used with a passive cabinet. Most players have cabs, they just need a head they can stuff some batteries into for power. Carvin Stagemate does 100 watts @ 4ohms, so it's definitely possible to get some real power (greater than 30 watts) into such a head.