I had an early nightrider too (10W) that I used up until last year. The original lead-acid battery died, but I replaced it with another for $20. The 10W bulb was too dim, so I ran it with a 15W which, in hindsight, probably wasn't a good idea. One evening before a ride, I turned on the light and nothing happened. I figured the bulb was dead, but actually what happened was the excess current to power the 15W bulb had eventually melted the insulation around the wires and it shorted. Caused a small fire inside the light which quickly melted all the wiring. The light itself is quite simple and I'm sure I could fix it if I bought new wires, but in the end, I decided to buy a nice LED light instead (a Dinotte 800L). I'm very happy with the Dinotte and don't miss the nightrider at all.