Operating mics on the street

[UCO]

I have run into a snag getting my mic operational for the street. So My question what power sources are available that are light, Rechargeable and efficent? I have been shot down with the moto battery and the amp can won't do the job. So Has anyone developed a brillant ideas about this. That they are willing to share. I was looking into trying to rig a 14v drill battery to a power inverter, Some information from the crew would be helpful.
Thanks heaps
UCO