Step 4: Solar panel mounts
Once your wires are all routed and zip tied, your batteries and panels held securely down, double check every thing and you are ready to go.
This Solar Powered Trike does about 15-18 mph depending on the weight of the rider. The furthest I have gone is a little over 10 miles with small hills and little pedaling, and the battery meter still read full (green) at the end of the trips.
At ten miles, the voltage drops to around 36V, safely above the controller's cut-off voltage. If the batteries are kept from discharging too low the panels take about the same amount of time as the plug in charger, since both the plug in charger and the solar charge controller charge with constant wattage. With constant wattage charging, Power, (P), and Ohm's law again (P=V*I), the charging current goes down as the voltage goes up, as the batteries near their fully charged state.
What this means is if you keep the voltage from dropping too low, the panels provide adequate current to match the charging speed of the plug-in charger, but if it drops below a certain point the panels are slower at charging. This is easily avoided since my typical trip range is around 3 miles or less, semi daily at most, so low voltage not an issue, but on longer trips I bring the multi-meter.
The Trike cost a little over $910 to build
Schwinn Meridian Trike
Q-cell Mono-crystalline Solar panels:
$ 95.00 www.solarseller.com
Electric Hub Motor Kit
$260.00 www.goldenmotor.com- also sells regenerative braking motor speed controllers
$ 60.00 Earl's industrial liquidation, Hawthorne, CA
High pressure tubes $ 15.00 Any bicycle store
Other solar trikes / information
The last picture is a scan of a page straight out of Dr Reza Toossi's book,
Energy and the Environment, Sources, Technologies, and Impacts.
Book information / purchase