20 days crossing the Atlantic. Autopilot steering 99% of the time. One 140W solar panel. On our best day our net Ah loss was 50, on our worst day it was about 100. Yes, we did have to run the engine about 1 hour a day on average, but we still only used 20 gallons of fuel for the entire 3300nm passage. In my mind we traded off needing to motor to keep the boat moving and adding several days to the passage for having to run the engine a little to charge the batteries. Not a bad trade-off to me and we can improve this significantly with an HO alternator and more than 1 solar panel and/or a wind generator. I expect to get to net zero consumption even with the autopilot running continously with not much additional effort.