I read the manual a little. The battery life part.
Battery full? Check the battery status using the battery indicator on the display. To ensure reliable performance throughout your dive, the battery must be sufficiently high. A new lithium primary cell (SAFT LS14500) allows up to 50 hours of diving, a quality alkaline AA battery (e.g. Duracell Ultra Power) about 20 hours. a lithium 1,5V AA battery (e.g. Energizer E2) about 30 hours.
The above is base on diving hours... So.. If we do a week long trip. U probably need to change the battery after that?
What is the rate of battery change are u looking at since it does not really say with sleep mode and stuff.. How long will it actually last...