Step 4: Solar panel mounts

Picture of Solar panel mounts
solar trike 034.jpg
solar trike 045.jpg
wiring diagram.bmp
Now you have to figure out how your going to mount the panels on your vehicle. Hinges were welded on the baskets to mount the panels and allow them to tilt for access to the basket, with rubber hold-downs on the other side to keep them from opening while riding.

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.

Cost Breakdown:
The Trike cost a little over $910 to build

Schwinn Meridian Trike
$250.00 www.K-Mart.com

Q-cell Mono-crystalline Solar panels:
$330.00 www.Ebay.com....

Charge Controller:
$ 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

Total $910.00

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


jimbo134 years ago
my calculator says it costs $ 1,010
just a question...how long it will take to recharge the bateries?
Bobert1906 years ago
I just started thinking about building a bike that would charge the battery, then power a motor to make my bike go much faster. I like speed and I thought it would be fun to give this a try. Do you think this will work? and Thanks this gave me some good ideas. Sometimes I just go the hard way.
fearfactor6 years ago
Wow! What a terrific project. Thanks very much for this well documented instructable. I'm busy pricing components to build my own solar trike right now ;-) Lucky for me, I get plenty of of sunny skies for the solar panels here in South Africa!
atb19916 years ago
My friend and I are building a similar bicycle as a project for our school, but I'm having a very hard time finding the correct solar panels. Could anybody help me out? I have looked at these: http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200328565_200328565
And the Q-Cell website offers no hint as to where to purchase their panels. Oh and one last thing, and ideas as to where to purchase the best batteries? Money is an issue.... Thanks.
I bought some solar panels at Harbor Freight. Might try there. Also, I think Northern Tools Catalog may have had some too. Hope this helps. Donna Long
Chwlo7 years ago
Very cool, I like how you kept it simple but still got the job done. I have a 16 mile round trip to work and I am a active fat person 310. I can put any thing together but don't know jack about figuring out motor size or battery needs to do a project like this. If you don't mind could you post the ideal numbers for making this same project for us BIG PEOPLE, we like to make cool stuff to.
I have an electric moped with a 36v hub motor very much like this it came equiped with 3 12v 12Ah batteries in series and I added another pack of 3 7.5Ah batteries that fit in the trunk for longer trips. the bike itself was 160lbs. I'm 245lbs I could do about 18mph on level ground and my longest trip was about 17 miles. The electric moped is currently under the knife being uped to either 48 or 60v with a custom controller while I ride the '78 Honda hawk I built last winter. sure it's not electric but it gets about 60mpg.
dpearce1 (author)  Chwlo7 years ago
This motor would pull you just fine, but if you need more power 1000W hub motors are available. For more range, you need more batteries, but for 8 miles to work, just let it charge in the sun while you are there and it should make it 8 miles back easily.
Nice! Well done! Would be good if you could mount the batteries down low out of the rear basket so that you could still use the rear and front baskets for groceries.
SirJoey7 years ago
I read about a solar golf cart with a 55 mile range. What would be involved in building a trike with that kind of range, & what would it cost to build, not counting the trike itself?
robhoski7 years ago
A wiring diagram would be nice. Can you post one? Signed ... Hopeful.
Dualies7 years ago
is it possible to put up a vid of the trike in action?
jacoby3087 years ago
Very nice project indeed. hope you get your A :) I would suggest having batteries also charged whenever you pedal, so it would be at maximum efficiency...
Your project rocks! I saw it riding around the campus the other day. Great job! And I recognize that guy riding it in your picture! He cheated his way through every class in college! Haha.
Few questions, how fast does it go? And does it have enough torque to make up a good hill?
15-18mph dependin on rider weight. read the thing!