Originally Posted by sierrabob

I have about 20 hours of heavy rain exposure to my Magicshine batteries. With just a bit of liquid electrical tape on the wires and cells, I have not had one problem with water incursion. One battery was kept in a seat pouch, but I just wrapped the other around the top tube.

The only problem worth noting is that the 5 mode Magicshine light interferes with my Sigma bike computer cadence as the voltage wanes and the regulator boosts current to maintain wattage. The older 3 mode light does not cause this problem.