I wired 9v batteries to (2) LED's by DGLIGHTS, the Palm65, and the bigger one (can't remember name, but is 35 watt equiv.). They both had what appeared to be full power for an hour or so, then the bigger one started diminishing (by eyesight, I wish I had instruments). The smaller LED seemed in full power for another hour or so. I started two days ago, and they are both still on, but significantly faded. I was under the impression they would not fade when voltage dropped below requirement, instead they should go out or start blinking. But they both faded. The main purpose of this was to test usability of battery powered fixtures for demo's. I did a demo set up the other day which was double my usual time (6 hours, not including presentation/consultation). My next test will be around my own property, placing these portable lights, and turning my halogens on and off to compare similarities in effects, including beam spreads, apparent color temp, and intensity. If they are close, I will probably use a combination of transformers and these LED portables, to reduce my set ups by 1/2 the time, minimum. A good test will also be palmetto trees and other tropicals at my neighbors'.