The process begins with gathering the necessary components: a 9V battery, an LED light strip or bulb, an on/off switch, wire, electrical tape or a soldering kit, and Velcro or adhesive for mounting.

The battery monitor circuit in Figure 1 can be very helpful for any portable equipment powered by two 9-V batteries. When both batteries are in good health, an LED produces short bursts of light every ...

3V is sufficient to turn on any LED, but is within its reverse break down voltage rating (that is why I did not use the common 9V battery). Short circuit current is approx. 30mA. I used a 3V lithium ...