Battery life of any green pointer is likely to be much worse than that of the simpler red variety though for actual uses as a *pointer* (what a concept!), it probably doesn't matter all that much. The quasi-CW and pulsed variety should be somewhat better in this regard. (The "spec" sheet that comes with the Edmund Scientific L54-101 green laser pointer claims a 3 to 4 hour battery life from a CR2 lithium cell though I'm not sure I believe it.) There is no functional advantage to the pulsed system (it's actually less desirable since the spot breaks up into dots when swept over a screen) but it can be made much more efficient reducing the need for thermal management and extending battery life at the same perceived brightness for these current hogs.