It is late at night, you are working on a project and you find that your electrical multimeter has a dead battery.
This happened to me, I looked everywhere but there was nowhere I could get a 9V battery until the morning. Not ready to give up yet, I decided to make a quick and easy solution to test continuity in circuits.
Step 1: Materials
This instructable is based around a battery powered LED light. This particular light came with a bit of double sided adhesive tape to stick in a cupboard or under the stairs for extra light but I am sure you could adapt a torch in the same way. You will also need an old cable such as an old phone charger or USB cable pictured here. A USB cable may be better as the cables inside are individually insulated. The last thing you need is something to accurately place on the terminals you wish to test. All i could find was 2 small pins that worked quite well but larger nails would work also.
The tools you will need include:
Small flat head screwdriver
Long nose pliers
Step 2: Dismantling
With the flat head screwdriver you can lever the battery cover off and remove the batteries.
Once the batteries are removed you can squeeze the flat head screwdriver in between the battery housing and the outside casing. With this light the casing popped off quite easily to expose the circuit board with LEDs as well as the wires connecting the battery housing.
These wires connecting the battery housing to the circuit board are what we will be looking at in the next step.