Change the battery percentage warning on MacBooks?

Question

Is it possible to modify when the "Low Battery" sign appears on a MacBook with Snow Leopard? For example, currently, it warns you about a low battery when it hits 10% of the overall battery charge. What if I want to set it to alert me on 15% or on 20%? How do I do that?

Answer 1

There is no way of changing the internal notifications. The only thing you can do is create your own new ones.

set a to do shell script "pmset -g batt | grep %"

set text item delimiters to tab
set a to text item 2 of a
set text item delimiters to "%"
set a to text item 1 of a as integer

if a < 20 then display dialog "Battery at 20%"

This code when run will check the current charge of the battery and prompt you if it's under 20%. You would have to run this script at small intervals for it to work properly.