[ColdWater]

LEDS work on 3.5 volts and low amperage so they are not power hogs. You can run 'em on just about any power source. What you DON'T want to do is run them from a transformer from 120v. You're bleeding off the excess in waste heat. That's why I'm designing a battery powered/solar charged system for a couple of rooms.

Your 'battery' probably bleeds off more waste than a transformer.

[hoosierham]

Neither the battery nor the transformer waste significant enegy if properly constructed.Transformers are on the order of 99.X % efficient,else the utility transformer on the pole would burn up due to the amount of power you and your neighbors use.

The regulator and rectifying devices are where energy is typically lost as heat in the process of converting alternating current and varying voltages to the precise steady direct current needed for LED room or reading lights ,and also for the many electronic toys in our homes. As much as half the total power used by your TV,VCR,computer,and stereo is lost as heat before the ICs and displays convert the power into light and sound for your enjoyment.

Switching type power converters are theoretically more efficent at the cost of increased complexity (higher design cost and single purpose use)and they can be the source of annoying high-pitched room noise,lighting flickers,and interference in the picture or sound of other devices.

TANSTAAFL =There ain't no such thing as a free lunch.