Open an airplane with an ELECTRIC engine in Plane-Maker. Now go to the STANDARD menu, SYSTEMS item. In that window: Go to the ELECTRICAL 1 tab and enter your battery watt-hours. Go to the LIMITS 2 tab and enter your nominal battery voltage and max amperage… these numbers multiplied are the max power output of the battery. Go to the ELECTRICAL 2 tab and simply drag the curve up and down as you like: This is the available power at each state of charge! Drag the curve to be accurate as needed for your battery. We default to a standard asymptote but you can set as perfect for your battery design.