LED's generally consume 50mW (mili watts) of power each and have a lifetime of 10-100 years. That is unless they are overpowered much like overclocking. Sometimes people will use more power to get a brighter LED at the cost of lowering the life span of these things which I was curious if Nokia did to get a brighter instantaneous flash.

Anyways, with two LED's in the unit you should be consuming 100mW which is similar to WiFi power usage at it's highest point of transmitting. So, I would guess you should be lowering your all day power level by about two hours if you left them on.