Solar-Cross (e bike)

Welcome, I'am Terry Hope a self-taught solar electric vehicle inventor/designer/builder. After committing 3 years of my life building my first EV (THEKPV) I had gathered enough knowledge to begin another solar EV project which I named Solarcross.

This solar e-bike began as an 1998 Specialized FSR bike frame and was custom built for my application, the complete bike cost me $200 CND. Converting to a solar ebike added an additional $500 to the cost.

Several hardware designs are unique about this ebike, the custom freewheel crank consists of three sprockets, starting on the outside is the 80T (tooth) chain sprocket which the electric motor drives. Then behind the 80T sprocket is another sprocket 42T and behind this is another which is just 22T. The two sprockets rotate the rear wheel by regular bike chain, the smaller 22T sprocket has a top speed of 22 kph without any need to pedal by the operator. The larger 42T sprocket can achieve +40 kph or over 50 kph with operator providing pedal input. The kph previously noted are powered by a 24 volt battery pack, basically half the voltage required of most Ebikes found in 2011.

80% Completed
Custom freewheel crank
Custom motor mount
Custom solar panels

90% Completed
24volt Controller
24v 500 Watt Motor
6s1p 5000mah Main LIPO Battery
2x 4s1p LIPO 5000mah Booster Packs Wired In Series (SPDT Rocker Switch) With Output From Controller

SolarCross

Electric bike

Ebike MTB

Rider View
Red Emergency Kill Switch
Two Booster Switches 3rd Switch for Solar
4x DPDT to Route Solar Output to Batteries
4x Voltage Meters for Battery Packs & Solar
Watt Analyzer Wired Directly Before The Motor

Inside of solar panel

Solar Cross

Another unique design feature is the custom solar panels which are hand built using aluminium angle, aluminium rivets, and 1/8" polycarbonate. Built ultra lightweight based on the high number of holes drilled through the aluminium to remove as much bulk material as possible. Photovoltaics consist of 18x 6"x6" mono crystalline solar cells @ 3.8-4watts output each providing an est. 8.7volts (9v minus diode loss) and controlled to recharge any two cells from either booster packs and main pack.

The remaining 10% of the build entails installing the top sheet, a highly transparent lightweight FEP film (96%), and safety lighting.

Update 9/10/2011:
good news: 24v + 16v booster battery, has enough torque while sitting on the ebike to spin the back wheel and complete a donut in gravel / 5t-80t
bad news: twisted the motor shaft (11mm) into two pieces, snap right before the copper windings. - both rear shock mounting bolts broke, but didn't fail. Replaced the upper, but the lower broke inside the linkage threads.

Additionally, installed 6 PV cells onto top panel, these 6 cells provide enough voltage to ride and to turn the wheels without any pedaling (1-3kph). I road down a street 90 degrees sideways from the sun on 3 volts solar power / I even switched between 3 gears... interesting ...

Left:
Solarcross PV panel sits atop handle bars
- open voltage here is 3.3volts & current is 7.1amps
- very light weight / guess - 2lbs or less
Right:
750 watt motor with broken shaft
- shaft broke off in the center of the coils
- 5 tooth sprocket

Solarcross E bike invented by Terry Hope - 05.15.2011
Tel: 011 562.726.3411