How do you hook up LEDs to a battery?

Question

i wanted to put some on my bike but i dont know how to hook them up to a battery

Answer 1

it is a diode, that means that it will only conduct in one direction. How to determine that? look at the diode, you will see two contacts inside the lense, the long one is negative and the short one is positive.

Once  you have determined polarity, now it is time to figure the voltage. You cannot run an LED directly off a battery, it just cannot be done. Common battery voltages are 1.5v per cell. A LED requires about 2.1v to cause it to light (conduct). This means that you need two batteries in series, but 3.0 volts is too much and will destroy the LED. So, how to feed it? You use limiting resistors. You place a resistor in series with each LED to get your voltage drop.

I have always used the rule of thumb for LEDs, a 470 Ohm in series with a Vcc of 5V, 680 Ohm for a Vcc of 9V and 820 Ohm in series for 12V. You can use 1/4 watt or 1/8 watt resistors.

There are hundreds of web sites with LED projects, go check em out.

Answer 2

Two ends to the LED right?

A Positive and a Negative.

Attatch two wires to both ends of the LED.

Attatch one wire to the positive side of the battery.

Attatch the other to the negative.

Wah-Lah!

I reccomend solder for a bike and possibly a switch somewhere in the middle of the wire to turn it on and off

Answer 3

ok just follow the guy above me, but for crying out loud he didnt even tell you how to tell the difference between the positive and negative legs did he? the side with the little flattened bit (youll see what i mean) is negative.