When I pulled out the set of bar-end lights, I found water in the drop handlebars. Is it safe to drill a very small whole in the bars (like what many rims have) to release the water?

Also what is the best way to protect these bar-end lights from water? I cut a sleeve from an old 23cm tube and slid it over the circuit board and battery. But that doesn't protect the furthest end of the light.

http://www.performancebike.com/shop/....cfm?sku=17651 <--- light has no protection for circuit board or battery...moisture in handlebar will probably wreck the light