6Volt Headlight Help

[stepper]

Hey guys,
I need a little help here. I am looking for a headlight for my Space BIke build. I have found several lights that can fit the aesthetic bill but have some questions on powering these lights. Basically I am thinking of getting a 6V headlight or emergency light and connect up 4 "D" cell batts at 1.5 volts each. Am I thinking this up right? And if this is right then will that possibly mean I will get a good amount of light but for only 15minutes or so?

I have never been good with electricals and I am basically clueless.

If you guys have any other suggestions then I am all ears.

Thanks,
Jason

 

[socal_jack]

A 6V bulb intended for usage in a bike headlight will probably be rated about 3 Watts, which means 0.5 Amp draw (3/6). Typical D-cell is good for 12000 mA-Hours or 12 Amp-hours which means 12/0.5 = 24 hours burn time ideally. But typical Akaline D-cell degrades quickly for burn time above ~0.2 Amp so figure about ~6-8 hours of reasonably bright light. So you'll do much better than 15 minutes but after 6-8 hours depending on use it'll be a noticeable drop like 3W vs 2W then a slow slide into a yellowish darkness.

You can replace the incandescent bulb with an LED, get more/brighter light and about 10 times the battery life though. Rechargeables sometimes do better with a heavier load also.

 

[Markm]

sylvania makes a "click and stick" L.E.D. light that is pretty bright and fits in some larger headlights...
Clothes pin had a how-to somewhere...check the how to's :mrgreen: :mrgreen:

 

[socal_jack]

I usually just get one of these Night-Ize brand Maglite LED upgrades at Frys, pretty easy to adapt for headlight without hacking the whole thing up

 

[Crassly]

The old balloon tired bikes like my 52 Hawthorne that came with Delta 6 volt sealed beam headlights used a 6 volt lantern battery in the tank for power. I don't know how long one would last, but I'm sure it would be much longer than 4 "d" cells.

 

[stepper]

Thanks for the help so far guys.
I just got back from my local Pepboys and they had the perfect sized non sealed 4x4 fog lamp in 5.5" diameter. the only problem is they want $40.00 for a pack of 2 and I only need 1. I think I'm going to try a place down the street that sells a bunch of mech junk. Hopefully they will have something there for cheap.

 

[socal_jack]

If you were talking about powering an auto headlight or foglight from a 6V set of D-cells, then yeah about 15 minutes at best, batteries will probably explode first though.