If you think you might be at risk of fully draining and damaging your battery it's worth installing a battery protect:
www.victronenergy.com
It costs much less than a battery and can prevent a lot of hardship when you're on vacation.
BatteryProtect - Victron Energy
The BatteryProtect prevents the battery from being damaged. It disconnects the battery from non-essential loads before the battery is fully discharged.
