We tried battery powered lights. They just do not last long enough.
Many of the discount stores (Lowes, etc) offer 500 watt lights at very low prices. I have found them for less than $10. Yeh, I know electricity and water don't mix! We tape up the connections and keep the cords away from the water as much as possible. We also use these lights for doing flat work at night.
Tidy Powerwash Service, Inc. P.O. Box 781, Catlin, Illinois 61817 Phone 217-427-5557, Fax 217-427-2632 We are a commercial cleaning contractor serving East-Central Illinois and West Central Indiana since 1984. http://www.tps-inc.com/preswash.htm
I also have been using the Halogen lights. They have been working well so far. I also use the headlamps that I use when i am climbing my treestand to hunt deer. You can get them at most sporting goods and department stores. They work great for hands free lighting when looking in ducts.
I tried a 110 Volt light once. I did not know I could throw a light that far! Now I use mini-mag lights with a Mouth piece. the mouth piece allows me to hold the light in my mouth w/out drooling all over. The mouth piece is available from REI. What brand of headlite do you use?
We use 500 watt lights some on extention stands and some I have attatched to big spring clamps which allow us to clamp them to the lip of the duct so we can get light down the shaft or too other things on the roof.
Jerry is working with a company that provided us with this prototype. I don't have permission to show it, but I can show what it does.
We used it on an interior coil cleaning job for more than 4 eight hour days on one charge on one of those little handheld briefcase sized jumpstarters for your car. It is the equivalent of more than a 500 watt halogen light.