This article is from the Misc Bicycles FAQs, by various authors.
From: don@island.COM (Don Hermes)
A few weeks ago I posted a request for help in building a light for
use off road at night. I want to thank everyone who responded,
and I want to describe the light I put together and the really neat
ride I took with it. I'd post the list of mail that I got, but the
most informative piece was sent to me surface mail by Brad Grande.
Hopefully this will prompt him to post his article.
I got a 12 Volt 4 Amp Hour rechargable battery ($39.99), a charger
($25), a 11 Watt 12 Volt landscape spotlight ($6), some wire ($1),
connectors ($1), and a plumbing mounting bracket ($1). I drilled
holes in the back of the spotlight to mount the light on my bike.
Someone pointed out to me that I could have used a piece of plastic
and some screws to mount off two little holes in the connectors. Live
and Learn. I simply put the connectors on the wire, made a ground
(that may have just been superstition) put the battery in a little
frame mounted bag, connected it and was off.
I went for a ride the day before Thanksgiving in the Marin Headlands
with a group that I normally ride with. There were no moon and no
clouds, the views of the city lights were incredible. It's nothing
like my normall nightime commuting ride frought with traffic and
smog. There was something quite meditative about being (almost) alone
in the dark. I did feel a little nervous on some of the descents and
walked through some techincal parts, and my battery did wear down
after two and a half hours.
On my next time list: a switch, so I can conserve power when stopped
and when climbing, and take my Cateye as a back up and to use