Watt Hour Capacity of 27 Deep Cycle battery

Bill.Satellite wrote:
All that really matters is the AH rating. You can go here to take a look at what you can run for what length of time. If you are drawing 100amps (not what a TV draws these days but might be a good combined usage number) you would be able to run 4.7 hours to complete discharge. However, you never want to do that and a 50% SOC is generally considered the correct time to recharge. That leaves you with only about 2.5 hours usage at that rate. Take another 5-10% loss due to inverter inefficiencies and you are down to about 2 hours.
http://ep.yimg.com/ty/cdn/sports-imports/BatterydrainCalc.html

Bill,
All I want to do is select a solar panel system that will fully charge my two batteries each day starting with 50% SOC. I don't have room for larger or more batteries. I will limit my usage to 50% SOC. I only need to run my CPAP machine each night. Any extra battery capacity is just a bonus.

I want this for a horizontal panel system for 66 degrees latitude on August 1st. If I can achieve that I will be very happy.

Thank you,
LeRoy

PS I am going to buy a watt meter tomorrow so I know what the CPAP uses. It's wattage is not labelled.