Question: how many watts does it take to charge a battery?
Answer: 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. To put that in reference to something familiar, headlights on a car are about 100 watts.