help me to find the resistance value to connect some LEDs

[vivinthomz]

led

helo , can anyone help me to find the resistance value to connect some ( 12 , 24 , 48...etc series of white led ) in a 6 volt 4.5 ah battery,..... plz....?

 

[hameeds01]

Re: led

what the LED specification ??
current?
Voltage??

 

[vivinthomz]

led

3 watts white led in 6volt 4.5 ah

 

[Audioguru]

led

A 6V 4.5Ah battery can supply 0.45A for 10hours. It might be able to provide 4.5A for 15 minutes.

One 3W white 4V LED needs 0.75A so 12 of them need 9A which the little battery cannot provide.

We need to know the forward voltage range for the LED (I assumed it is 4.0V) to calculate the value of the current-limiting resistor for each LED.