The value expected to start charging the battery was 44RPM. while doing the test, the battery did not get charged until the wheel`s speed reach 50RPM. Therefore, the actual value was of by 6RPM. As the wheel reaches higher RPM, the battery is being charged with higher Amps.
The lowest RPM to start charging the battery was 50RPM, which is still good due to the movement loses along the system. The difference in the RPM between the actual and calculated values, is not that noticeable while using the system.
Even though, the requirement was being able to charge the battery at 44RPM, the actual number was 50RPM. That is because the calculations were done without accounting any loses along the system. Therefore, 50RPM would still be a good number even if it a little higher than the expected number.
Results:
RPM vs Voltage graph