I wrote a simple shell script battery.sh similar to Ludovic Drolez's Battery Bench. The main difference is I'm using /sys instead of /proc, which works fine on current OZ and kernel 2.6. My script will set the backlight to 10 (that's 21% and quite usuable), monitor battery voltage (and percentage) once per minute and suspend the device when the battery reaches 5%. Obviously screen savers, auto dim, auto suspend, etc must be off.

The purpose was finding out how my new (small) 1800 mAh battery bought from someone known as Lauter in forums performed compared to my old (large) 1700 mAh Sharp EA-BL08. I ran the script on my idle SL-C860 running OZ 3.5.4.1 GPE (when fully charged, i.e. orange LED off. The results were quite surprising: The Lauter accu does about 2 hours while Sharp's last for more than 7 hours.

Lauter 1800mAh (small)	1:59	log graph
Sharp 1700mAh EA-BL08 (large)	7:24	log graph