Most aggressive bulb in plastic assembly?

[Buck91]

I have a incan headlight assembly (the type that uses the tire-driven generator) laying around unused. The lens/reflector lamp assembly is in great shape, it just uses this weak little 6v 2.4w halogen bulb, so I'm thinking about building a battery pack and upgrading the bulb to something more usable.

Its got a number of marking on the lens such as "HS3" and K10734 and appears to have a similar design to automotive lamps, so I'm thinking it has a lot of potential for a great beam for a bicycle, but I really need to know how aggressive I can get on the PR bulb. I would think a bulb for a 6 cell mag would be fine, does anybody know the wattage on those? Any more powerful bulbs that could be used with a plastic assembly?

 

[BSBG]

I think the general wisdom was that an ROP Low at 11 watts was about the highest power that would not melt a Mag reflector after several minutes.

 

[lctorana]

6-cell Mag Xenon bulb is about 6W

The Eveready Dolphin Rechargeable has a plastic lens and bulbholder and runs a 6V 10W bulb as standard, so we know for 100% sure that 10W is OK.

Now 11W - that is on the limit. It seems to be OK in Maglites where the reflector does not touch the bulb, but does slowly warp and deform those reflectors that do. It depends how well made, and exactly what kind of plastic, the reflector is made of.

So - about 10W -ish.

 

[Buck91]

Very interesting. Both the ROP low and the 6 cell magnum star would be able to run off the same battery pack, correct? How about over driving the 6 cell bulb? Well, I suppose I should just search those as I'll bet they've been asked before!

 

[Outdoors Fanatic]

What about the Princeton Tec Shockwave?

 

[mdocod]

The only accurate answer is that it depends on many factors.

Setting a hard cap of "10W" for all plastic assemblies is entirely false as it is dependent on how close the bulb is to the plastic in the installation, how large a space the bulb has to heat up (air space), how much if any ventilation is provided, and probably most importantly, what the melting point of the particular plastic used in said light is, as this can vary quite a bit.

I have melted a few plastic lights running regular Mag 6 cell bulbs in them on a pair of li-ion cells, while larger lantern style lights will often handle 10+W even if plastic.

Experimentation may be required.

Eric

 

[nitesky]

This is a great question. I agree with mdocod. The size and and design of the assembly as well as the type of plastic are factors. I have melted a couple of units myself.

I have an Energizer Weather Ready (sure looks like a Dolphin) with a 5AH SLA and a ROP Lo bulb (nice output!). I have run it for 20 minutes or so with no troubles, but then it is rather large. I don't think I'll push the voltage past that though.

This sounds like a fun project. The HPX53, a 6v light for rechargeables, is another option.

 

[Nubo]

Since this is for a bicycle, you may have some cooling assistance from the airflow. Something that works while in motion might have problems if stationary for too long. I know my HID bike light says no more than 15 minutes of stationary operation. Just something to keep in mind.