Wattage of CREE - help needed

[AaronS]

HI everyone

I ride mountain bikes and do alot of night riding. I enjoy making up my own lights and am hoping i have finally found a forum where i may be able to get many questions I come up with answered.

First off the list is this one - i have just purchased this CREE off EBay http://cgi.ebay.com.au/CREE-LED-Bul...yZ106988QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

i want to get more specs on it, particularly wattage, so i can calculate the run time I should get from my batteries.

thanks
aaron

 

[znomit]

:welcome:

The LEDs run up to 3.5W.
These units have a driver circuit that takes the 3-8v from the batteries and delivers a constant current to the LED. Maybe as much as 1A.
How long your batteries last depends on the efficiency of the driver and the actual drive current, neither are quoted :thinking:

As well as this the quality of the LED makes a big difference.
Heres one that supposedly uses the latest LED. Might be 50% brighter than yours.

Check out the bike forum here too.

 

[AaronS]

Thanks for that. I rigged up the multimeter as the imput lead and it read 1.4 A on the brightest setting. drawing a bit more current than i would have liked. if it was 3.5W on a 6 V battery then i thought it would have been much lower, maybe 0.6 A. i dont really understand how LEDs work though.