Above you can see voltage and current data captured from a model PPG-R200-CC pedal power bicycle generator. Data was acquired using software from http://wattsview.com/. This graph shows you voltage and current throughout a 20-minute bicycle generator workout period. The person riding is a 43-year-old male that works out two or three times a week. Average heart rate during this trial was 120 BPM (beats per minute). The white trend line shows the battery voltage of the Duracell Powerpack. When the generator is not being driven, you will see that the Duracell battery is about 12.2 volts DC. You can also see that the built-in battery charge controller keeps the max voltage on the battery around 14.5 volts DC range. This is a healthy voltage / current level to best charge your lead acid AGM battery powerpack. The red trend line shows you how much current flowed from the bike generator to the Duracell Powerpack. Click on the amp-hour chart to see the total amount of amp-hours.
Above you can see power output data captured using software from http://wattsview.com/. This graph shows you how much power was generated by a 40-year-old casual rider who works out two to three times a week. You will see that the peak wattage hit about 160 watts of power output. You will also note that many times the watts trend hits the zero level. This is because the built-in charge controller has kicked in and protected the Duracell Powerpack from getting too much current which is not good for the small 28 amp-hour battery. Average heart rate during this trial was 120 BPM (beats per minute).
Data captured using software from http://wattsview.com/. This graph shows you the battery charging amp-hours from a 40-year-old casual rider who works out two to three times a week. The green trend line shows you that after a 20-minute workout, the total amp-hours reached 1.8. This took the Duracell Powerpack from a SOC (state of charge) of 10% to 30% while it had been powering a laptop data logger computer which consumes 20 Watts. This laptop was running the WattsVIEW™ software that recorded this data. To completely charge the Duracell Powerpack when it is dead, you would need to put in anywhere from 6 to 10 amp-hours, depending on how fast you ride.
Data captured using software from http://wattsview.com/. This graph shows you how many watt-hours came from a 20-minute generating period by a 40-year-old casual rider who works out two to three times a week. The bicycle generator system used was the PPG-R200-CC pedal power bicycle generator system. This measurement is useful because it allows you to compare the power output using the same metrics that the power company uses to charge you for electricity. In this case the total power output was about 25 watt-hours. If the session had continued on for a full sixty minutes it would have been approximately triple the amount the power, or 75 watt-hours. Converting this value to KWH, you get 0.075. Since 1 KWH from the power company costs ~$0.10 then you can deduce that one hour of hard work is worth less than a penny! Average heart rate during this trial was 120 BPM (beats per minute).
The data displayed on the above chart shows three test case scenarios where the bicycle generator load is varied from zero, to five, and then ten amps of current. The first case shows voltage output of the generator with no load—this is the white line. The second case is with a constant load of 5 amps—the red line. The third scenario shows you pedal power voltage output with a constant current load of 10 amps. You electrical people may be looking at the data attempting to approximate the internal resistance of the bicycle generator. For your convenience, that information is displayed on the generator internal resistance graph shown below.
FYI, a generator with an internal resistance of zero ohms makes the ideal generator—which unfortunately does not exist, but it is what many strive for. Internal resistance of a generator is bad because power is lost in the form of heat inside the generator, which is also called voltage droop, or IR drop. Below you can see that this bike generator has an approximate internal resistance of ~0.35 ohms.