use of batteries for lighting...controler question

[garym999]

For the mains bypass relay perhaps look at a circuit built around this...

Looks like it should be just the fit.

Others have mentioned cable sizes, this will be a real deal if you choose halogens but LED's or flouresents less so. Fuses etc. (at the source, battery) will be essential. The nice things with LEDs is that you will typicaly have 4 in series from one 12V fed, more if the driver steps up the voltage first, which some do. Back to the Halogens also take a look at 6v Halogens, these coming in smaller wattages and 2 can be wired in series to spread the light over given aera better.

Another light source that is very effcent and youve guessed it expensive is HID, the xenos you see on modern cars. These consume about

30W as opposed to 55W of the halogen it replaced. I think they give twice as much light out. You can find conversion kits on ebay.

[Jonathan Schneider]

Don't forget the traditional or possibly high frequency flourescant. Efficient and cheap. LEDs though all the rage barely exist in a form useful for lighting a room.

Jon

[Dave Plowman (News)]

But do you know the quoted life of these? Nothing like domestic lamps. And I thought the idea was to save money...

[Ashnook]

Thanks Gary, that's a very interesting device.

[garym999]

I think you'll HID lifetimes better than or on par with halogens but they would be application specific. As I said in previous posts Modern flouresents will be the most cost effective. And LED is positioned between the two and can light a room with good design (and no that is not a pendent in the center of a room).

Save money?? As with so many eco ideas the principle is fantasic but the captial outlay often rights them off. But if no one makes the effort or develops the ideas where would we be. And look at solar heating, micro turbines and PV the prices are all coming down.

[meow2222]

LEDs are close in efficacy to filament lamps. They have far higher price, poorer light quality and lower efficacy than fluorescent, but hype talks.

NT

[Andrew Gabriel]

Headlamps do indeed have much shorter lives than domestic lamps. Lives of these things are difficult to come by, but something like 250 hours for filament headlamps is the ball-park. For a car driven about 1/3rd of its time with the headlamps on, this equates to about 4 changes of each lamp in the lifetime of a car. (There are aftermarket overrun lamps around with much shorter lives.)

I don't know if the HID headlamps are intended to run longer, but there would be little point making them run much longer than

1000 hours, or they would be over-engineered for the lifetime of a car.