Question: how many watts does it take to charge a deep cycle battery?
Answer: Most folks seem to agree that 50% is a good compromise between cycle life and cost. The 12 volt 200 amp hour battery in question has a total capacity of 200Ah X 12V = 2400 watt hours. If you use 1200 watt hours that's 50% of capacity and it's time to stop and recharge.