Here is a battery monitor, it lights a led up on pins 0,1,2,3 when the battery is full:
Pins 0,1,2 when the battery is ¾ full
Pins 0,1 when the battery is ½ full
Pin 0 when the battery is ¼ full
No leds on when empty.
It uses a voltage divider so the picaxe will not get destroyed.
Here is the...