Here I have used a discarded Li-Ion Battery which is no more working in a mobile handset.
This Battery may not work in a mobile set but it has got a lot of juce left in it to run a small poket size rechargeable TORCH with 5 LED's. It gives a very bright light and does not need a recharge for quite a long time.
Step 1: STEP-1
1.- One PVC flat Box of size 2 x 3 x 1/2 Inches.
2.- One Single pole single throw switch.
3.- Five Very bright White LED's of 5mm size.
4.- One Discarded 3.6v Li-Ion Battery. (Lithium Battery)
Step 2: STEP-2
In this step follow the Circuit diagram and assemble the parts.
The 5 LED's are fixed to the PVC Box.
The Switch is fixed to the Cover of the Box.
All the 5 LED's are connected in parellel with a switch to the Battery.
LED's are connected PARALLEL because the output voltage of the
battery is 3.6 volts and the White LED runs on 3.3vots.
The longer leg of the LED is the positive pole and the shorter leg is the Negitive pole.
The positive pole should be connected through the SPST Switch, to the (+) side of the Battery.
The Negitive pole can be directly connected to the (-) side of the Battery.
Put some foam pieces around the Battery to keep it steady inside the box from any movement.
Put on the COVER and all is done....
Step 3: STEP-3
There is nothing special in this step but to see the Photograph and follow the the circuit.
To recharge the battery put it in your Mobile Handset and CHARGE.
Buy a Lithium Battery Charger which charges many types of lithium batteries.