I have 4 x 20 watts on each side of the boat, but here at 40-degrees north we rarely see more than about 7 amps charge at mid-day. Under sail it's more likely one side (of panels) is at least partially shaded, so at best we're getting about 3+ amps. Under sail we're using all instruments, the A-P, C-P and maybe radar and nav LED lights (particularly at night or in fog when we're not charging from solar anyway). Then there's the netbook, and charging various portable phones/tablets and MiFi etc.

When we're away from the boat the solar barely keeps up with the fridge, and the refrigerator isn't being opened and no lights/nav equipment is used. The best we can hope for now is to slow the rate of discharge with the amount of solar we have. I don't want to step up to adding an arch and paving the top of it with panels, and I have considered replacement with an Engel but I think we'd still need to use engine power or Yamaha generator occasionally to charge unless we increased the solar capacity.