Battery Fuel Gauge and Monitoring for pleasure boats (Primarily Lead Acid batteries)

We are building wireless sensor network for pleasure boats.  One of the sensor inputs will be to monitor one or several boat batteries.  Boat batteries are primarily large lead acid batteries.  We want to monitor the battery at rest with no load, with load, and when underway and being charged.  We will have access to events with known load and can aggregate and calculate various results from that.  It is sufficient to monitor voltage, but would be nice to add other valuable functions as well.  We want the connections to be very simple and vill need to limit design and functionality to accommodate. The MCU will be an ARM doing various sensing activities with input from other sensors.  We wish for the battery gauge and monitor module to be as independent and isolated from the rest of the circuit as possible.  Power drain must be very low. (uA)  We assume we will know when engine is charging the battery by measuring the charging voltage.  We are no experts on battery power management and are seeking any direction and assistance.  We would like to stay in the TI family as all our wireless work is based on TI technology.   The batteries are not very fancy and we want to bring some fancy technology to make them cool again.  Thank you for any help and direction.