we installed 4 x lifelines under our grand tour 2016. bought the boxes from airstream and riveted then place. also installed 4x 100 W solar panels from AM solar, new victron controller and pulled some thicker wires from the solar panels. installed a shunt and a magnum ME-ARC. the ME-ARC allows us to program in the capacity of the batteries as 320 AH (4 x 80AH) into the system. it calculates the state of charge rather than relying on voltage as a measure of state of charge (SOC). with this set up we have we typically end the day (sun going down) with 100% SOC, over the course of the evening we use between 5% and 20% of the batteries. 5% if we don't do much, 20% if we are running the inverter to watch TV and charge iPad, Camera, Dyson etc. (once inverter is running might as well charge the other gear). by morning we are down another 15-20%. The ME-ARC and shunt combination allow us to see exactly what the draws are. if you don't have an ARC then here is a suggestion. watch TV if you want. be sure to turn the LPG switch off (0.8AMPs) until you need it in the morning. Inverter draws 2AMPs before you turn on TV and DVD. leave fridge and freezer on running. they will cycle on and off all night. when you do go to bed power down as much as you can. this means LPG off unless you need the furnace then leave it on. be sure to turn inverter off. make sure van's radio is off (2AMPS). then you should be fine by morning.
we just did a trip from north of toronto to Baja Mexico and back. from Detroit to Nashville, the van's alternator was providing most of the power as the solar was not providing much due to cloud cover (if you install a victron charger you can see exactly how power you are getting from solar). once we hit Texas and all the way to Mexico we would be fully charged before noon. both solar and alternator were kicking in. because AGM's charge in three phases it takes a long time to get the last bit of charge. when we were parked for a week in Baja, or Moab where we had clear sky most of the time solar had us fully charged by noon. this allowed us to charge all of our other devices because there was a surplus of solar power available. (the last phase of charging is a very low amperage input). we have found the addition of the ME-ARC and victron very useful. prior to that it was more like a guessing game.. it was worse with the atkinson controller as it would read incorrectly. we can park indefinitely if there is bright sun, knowing what power you are consuming is the way to go