Solar Powered

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Solar Powered Electric Bike Project
Aaron Shipman Advisor Dr. Xingwu Wang
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Project Goals To successfully power a
commercially available electric bike with solar
panels. The bike is to be stored in a shed with
the panel(s) mounted on top. Electric bikes and
scooter are available for purchase today. These
vehicles are normally powered by a rechargeable
battery pack that is plugged into a wall outlet
after the batteries drain. This projects goal is
to replace the stock battery charger with one
that is powered by solar panels. This would
require minimal cost to sustain operation (i.e.
no charge for electricity, no cost for gasoline).

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• Tentative Bill of Materials
• Tiger Electric Scooter
• Battery Type Dual 12 volt, 10 amp/hour,
  rechargeable battery pack
• Motor Type 24 volt, 400 watt continuous / 800
  watt peak power
• Recharge Time 3-7 hrs (with wall outlet charger)
• Top Speed 15 MPH
• AP-30 Photovoltaic Module
• More than 1.8 amps charging current in full
  sunlight
• Weather / hail resistant
• Open Circuit Voltage 21.5 volts
• Max Power Voltage 16.7 volts

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Timeline Project Start Date 4/17/03 Parts 3-5
weeks (circuit design, selecting parts, delivery
time) Assembly 3-5 weeks Testing 2-4
weeks Estimated Project Completion Date 6/21/03
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• Project Status
• Ongoing Activities
• Correspondence with electric bike dealers and
  solar panel dealers.
• Budget acquisition and preparation for purchases.
• Researching in the area of charging circuits.
• Parts yet to be ordered, circuit yet to be built.
• Although the research described here is
  partially funded by the United States
  Environmental Protection Agency, it has not been
  subjected to the Agencys required peer and
  policy review and therefore does not necessarily
  reflect the views of the Agency and no official
  endorsement should be inferred.

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Charger Details The scooter has dual 12 volt,
10 AH batteries connected in series, charged by a
14 volt, 1.2 1.5 amp wall outlet charger. The
solar panels provide more than 14 volts, and more
than 1.2 A, so the circuit in between the scooter
and panels should limit the current and voltage
should they get too large. Also, the new
charging circuit should prevent the overloading
of the batteries. If the output from the solar
panel dips (cloudy day), the batteries will just
take longer to charge. This simplifies circuit
design. Different charging circuits are being
researched and one that meets the requirements
will be selected / created.
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Left Tiger Electric Scooter with detachable
seat / basket
Below AP-30 Solar Panel dimensions
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Project Benefits There are many benefits to
using solar power. Solar power is free, it just
needs to be harnessed. After the initial
investment, the solar scooter will pay for its
self. Operation of the scooter will be simple.
After being taken out for a ride, the user will
simply have to put the scooter back in its shed
and plug a wire in. No going to the gas station
required. The scooter will charge its self and
cease charging when the batteries are at full
load. A scooter like this is ideal in an area
where destinations are relatively close together,
like a small town or dense city. In a city,
electric scooters would cut down on pollution,
traffic in the streets, and use of
gasoline. This type of alternative energy has
the capability to greatly reduce emissions and
dependence on foreign oil. This work is
partially supported by EPA/CEER.