If you are talking about the compensating timer that has the dry down and the light output reducer feature then I'd say no. Since you are actually working with lux and not "seconds" and provided your head has the photo cell in it and its connected to the timer, that should take care of any fluctuation in the electricity going to your head. So even if there is some fluctuation in the electricity, which would cause more or less voltage hitting your head, and thus changing the output of light (stronger or less), the length between the beeps would change also, thus "compensating" for any changes in output.

Hopefully I explained that right...I'm dog tired.