LEDs

Measurements using 700mA driver from DealExtreme (10/9/2012)

With bridge rectifier and 2 LEDs

In 13.0v @ 0.4A = 5.2w

Out 6.4v @ 0.62A = 3.968w

76% efficiency

Without bridge rectifier

In 13.0v @ 0.37A = 4.81w

Out 6.44v @ 0.622A = 4.00568w

83% efficiency