BIKE LIGHT 500 Lumen "Mt.Bike" for under 10 bucks by Veggiecycle

Step 8 Put it all together and...

It should work like a charm..
I got this bike water bottle battery pack that is 5 mah with the quick charger from batteryspace.com. They have tons of great batteries on that site.

Comments

[muddyboots]

How long do 10 AAs last on a 20 watt bulb?

[Dunhausen]

Depends on the batteries. To convert a battery's amp-hour capacity to watt-hours multiply the amp-hours by the voltage (12) and then consider what wattage of bulb you're using. For a 20 watt bulb with 2600mAh batteries you're looking at 1.56 hours theoretical run time, and twice that for a 10 watt bulb. Concerning the project: rather than drill a hole for the conduit hanger I just reused one of the hose clamps from earlier to attach the device around the narrow section of the light. it worked out very well. A bit of rubber or cloth is good to increase friction with handlebars and prevent it from sliding. You could also paint a little rubber cement in there or something. Any ideas on a trickle charger circuit for this? Just needs to output >12v and ~90 milliamps and it would be perfect to leave it plugged in at night. Kind of defeats the points to spend $30 on a charger, $20 on batteries. :p

[QuikMart]

Mmmm... Don't be fooled by those manufacturers numbers. Those capacities are obtained at a much lesser discharge rate, more like 1/2C. At 20 watt your at (2,6/ (20/12)) 1.56 C. So you can't expect less run time. Duracell provide very good information on their website... You can aslo use a cheap Sealed Lead-Acid 12v battery wich cost 10$ and a generic charger for about 5$ - 6$...

[mtaylor22]

My experience with 12v 7ah SLA batteries is that they are HEAVY (6-7 lb), and they do not like being discharged at the rate that these MR16 bulbs take! I get run times of 45min to 1 hr. Sometimes more if I stop running the light for 10 min or so between runs of 30min. Also, they fail in cold weather, which is the main time I need my light!

[christopherk239]

i made 1 of these lights but i found if you use the led replacements instead of halogen bulbs your batteries last a lot longer. run time on my light with a 50w halogen was about half an hour and with the 60 led bulb its about 4 hours

[mtaylor22]

Thanks for the instructable. I will keep playing around with the MR16 because I like the light frequency it puts off, and its a fun hobby. Try batteryjunction com too for your lighting hobby or just buying a complete light. They cater to cyclists, cave spelunkers, and hunters.

[mtaylor22]

I really like your idea of the RCA connector. That looks like a strong, low resistance connection, and should not pull apart too easily.

[joshtp]

i built it, but instead of using rca i just used normal cable and some metal piping substitutes the pluming. my only problem is that it simply isnt that bright. when firts testing the super simple circit.of battery,switch,bulb. it was awsome. but now its far dimmer. Any ideas?