I think there was about an inch of insulation to start with. My insulation improvements were based entirely on the experiences of owners of similar boats (and fridges) who went to hot places. I learned what worked for them and tweaked that a bit. Yes indeed! We tend to baby the batteries and ourselves with frequent marina tieups. But here we are at Morro Bay on a buoy (easier than anchoring). The last few hours here was with engine so the batteries were fully topped off after running electronics and autopilot all night sailing from Monterey. Now, the panels are loafing along dealing with a microwaved cup of tea water, the longrange wifi antenna and the boats laptops, etc., oh yes, and of course the fridge. The solar panels will be well tested while we're on the hook in Mexico.