A safety headlight with a battery power monitor is provided. The headlight includes one primary light bulb and at least one LED bulb. When the battery power begins to fade so that the primary bulb is in danger of going out, a sensor in the headlight switches power to the LED bulb(s) to provide safety...http://www.google.fr/patents/US7178955?utm_source=gb-gplus-shareBrevet US7178955 - Safety headlight
