# Headlight LED with two bulbs



## Vetteman61 (Jun 25, 2020)

I'm want to get the headlights working in my 64 Foremost (murray built space weight) and convert to LED, but I don't know much about how LEDs work.  The bicycle holds two D cell batteries.  I see on the forum where people are using the 3v LED bulb because each battery is 1.5v, but all the ones I see have a single bulb headlight.  My headlight housing has two bulbs so I don't know if the same bulb they use would work with mine.

Here is the type of bulb I'm wanting to use.  Will two of these work with the Double D cell batteries?


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## Roger Henning (Jun 25, 2020)

Maybe it is the right voltage.  If it doesn't work make sure the batteries are the right way to the bulb as reverse voltage does not work.  LEDS are polarity sensitive.  Roger


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## Archie Sturmer (Jun 25, 2020)

It depends.  Those look fairly bright, (with LEDs on 5 sides); not sure if cheaper ones may be found that are not so bright.  Depends if they are for looks, or for actual night-time riding safety; (and then, how safe or how bright).  The omni-directional 5-LED versions work better on lights with parabolic reflectors, (as single LEDs only illuminate forward).
Also, there are adapters to convert those "D" cells to (3) "AA" cells at 4.5V x 2 = 9v.

An improvement over filament & halogen bulbs. 
The parallel versus series matters for both the batteries and the bulbs. 
Most bike lights have parallel bulbs, as observed by 1 bulb lit, while another is not lit. 
Parallel bulbs do, however, in addition to being twice as bright, drain batteries twice as fast.
Sometimes, I can buy better alkaline "AA" batteries in bulk, compared to economy "D" (lead-carbon?) batteries.


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## Vetteman61 (Jun 26, 2020)

Thank you for the reply.  My reflectors do have the chromed concave reflectors so that's why I was considering the multi-sided LED.  That's good to know as I was not aware of the AA conversion.  I understand that voltage can be adequate or not depending on if wired in parallel or series, but it's been so long I cannot remember.  I'm curious if a 3V LED would work when used with a headlamp that takes two bulbs.  The only examples I can find so far on the site are single bulb headlamps, which of course would work fine with two D cell batteries.


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## Rivnut (Jun 26, 2020)

Your reflectors are concave but are they parabolic as mentioned above. Do the sides of the concave reflector surround the bulb in such a way that light striking the reflector's surface is directed forward or are they at such a narrow angle that any light from the bulb will just be reflected to the side?  I use original lights for aesthetic you only.  I have some really powerful LED flashlights that clamp onto the handlebars for night riding.  The clamps are plastic with hard rubber grips and they clamp to the bars with a quick release handle. They also make it so much easier to change batteries - no tools required, just unscrew the cap. I also you a clamp on flashing red rear light.

A friend I ride with clamps two lights to his handle bars - one constant LED light with which to see, and one strobe LED with which to be seen.  Both are identical lights, they are programmable with the 9n/off switch.


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