 # FAQ

This schematic and bill of materials  in the PDF file below shows a simple solution to suppressing too much Voltage from a human power generator.  This happens when an over excited rider decides to go crazy on the generator system at a speed that is excessive.   When  using  pedal  power  bike  generator   it  is often  necessary  to  use  this   type  of   circuit  to  protect  a 12V  light  bulb   from  being blown. The 300 Watt 12 ohm power resistor in the bill of materials is adjustable and can be kept from over heating by installing a fan next to it. How do I remove the tire from my bicycle?  Watch video instructions shown   Here

What is a Watt?  A Watt can be compared to Velocity  which is a measurement of how fast you are going.     When a Watt is combined with a time value such as second, minute, hour, then it becomes a measurement of work done.    The formula for Watts is Volts x Amps.

Below is actual data collected from a bike generator during a one hour session.  The white line in the graph below shows actual Voltage of a lead acid battery being charged by the bike generator.   The red line represents the Amps  measured.

At one point in the chart the Amps reach a value of 21.  At that same point, the Voltage reaches about 14.  When we multiply 21 x 14 we get  294 Watts.   The second graph below in green is the Watts graph.  How much energy can I generate with a Pedal Power  bike generator system?

Typically an adult who exercises on a regular basis and can generate about 100 Watts of power over a one hour period.   A competitive rider can average 200 to 300 Watts during a one hour period.     To put this into perspective,  that much energy would power a cell phone for over a month.   But would run a 500 Watt blender for only a few minutes.    The calculations for energy produced are in “Watt Hours”    which is calculated by multiplying  Watts x  Hours.    The energy unit used to charge you for power being delivered to your home is “KiloWatt Hours”   Which is simply Watt Hours  divided by 1,000  .

What kind of things can I do with energy generated from my body?

You can:

• Charge a deep cycle 12V DC  battery (Using a blocking diode)
• Charge cell phones  (Using a blocking diode and Voltage regulator)
• Light a room with an LED light bulb (Using a blocking diode,  Voltage regulator,  and AC inverter).
• Charge a laptop computer  (Using a blocking diode,  Voltage regulator,  and AC inverter).
• Power a 12V  blender to make drinks or smoothies at a party
• Power a leaf blower pointed in the up direction with a pin pong ball floating  in the air.
• Power a wheat grinder to make bread (Using a blocking diode,  Voltage regulator,  and AC inverter and portable powerpack)
• Power a 50 Watt flat screen  TV  and DVD player  (Using a blocking diode,  Voltage regulator,  and AC inverter).
• Power a PA sound system  (Using a blocking diode,  Voltage regulator,  and AC inverter).

What are the calculations regarding charging a 12V battery?

Some people like to store their energy into a potable battery powerpack.   A typical battery size for a powerpack is something near the 25 Amp Hour range.   Amp hours is different than “Watt Hours”  because the unit of measurement is in “Current”  or “Amp”  instead of “Watts”  .     Amp hours can be converted to Watt Hours if you use the Voltage rating on the battery  which is typically 12V DC.     Amps X  Volts  =  Watts  so in an ideal world   you could say that  a battery with a 25 Amp hour rating can put out 25A  x 12V  =  300 Watts   during a one hour period.

Below is a graph showing Watt hours.  The green line on the chart below shows you the output of the belt drive pedal power generator system.    The red line represents the Amps of current flowing into a battery  and is associated with right axis on the chart in red font.   The data was captured by the WattsVIEW power monitor.   In this demonstration the person riding the MNS Power generator system  started pedaling at about 3:07 PM  and stopped at around 4:30 PM.    The peak current during the time period shown was about 12.5 Amps.    You can see that the average current  during this time was about 5.5 Amps.    So if you had a 25 Amp hour battery  then the time required to fully charge it from being completely dead would be calculated by dividing  25 AH /  5.5 Amps =  4.5 hours. Can I get more energy out of my system  by using  two generators  instead of one,   or by using  a flywheel,  or using a  bigger generator  or higher gears?

The human body is limited too how much  energy it can put out,  no matter  how you setup your generator system,  the human body can only put out an average of 100 to 150 Watts during a one hour period.     Putting a bigger generator on your system does not give you the ability to generate more energy.   It may make your system a few percentage points more efficient  like from 94% efficiency to 95% efficiency  (Where efficiency is  calculated by  power out of the system divided by power into the system.)

We were  recently  asked to analyze a a pedal power system that an inventor had claimed would allow a person to generate well over 1,000 Watts of power.   He had a fly wheel on the system and TWO generators.   Dozens of investors had dumped in hundreds of thousands of dollars into this invention.    The results of testing the system out by measuring current to the battery bank showed that this inventor had made a huge mistake in his claims.   He had made two mistakes:

1. He had assumed that because his generator was rated for 1,000 Watts output  that meant that a person could automatically put out 1,000 Watts on  a bike generator
2. He had assumed that putting two of these on a pedal power system would automatically double his output to 2,000 Watts .

The rating on a generator or PMA (Permanent magnet alternator)    simply states the max rated power output of the unit.    There is no free lunch.

Some people have tried adding a fly wheel to the system to store the energy.   This  does nothing to increase power output.  It simply stores your energy  represented by the formula  for kinetic energy stored in a rotating body which is