Okay, so I took a stationary bicycle and modified it with a large DC motor from an electric scooter. The motor is rated for 24 volts at 100 watts. When pedaling it is easy to generate 50-150 watts. I put a current sensor and a voltage sensor to monitor the power being used by electric devises attached to the bike. This includes fans, lights, speakers, and measurement tools such as a heart beat sensor. What I am trying to do though is calculate how many calories the user is burning based on the wattage being used. I did some math in the program and I can accurately calculate the power being used and convert that to calories but I can tell its much to low for a stationary bike. I did some googling and consensus says a stationary bike will burn 200+ calories in 30 minutes. I am getting about 20-50 with the pure electricity. I assume that there is inefficiencies in the bike and gearing as well as when a human makes the movement. Is there anyway I can calculate this to make it more accurate? If so how? I know I can measure how much power the motor uses to spin the bike parts.
Thank you guys!