Solar Vehicle Build Help Needed


New Member
Oct 27, 2020
Before I start I want to apologize if this gets a little to long. I also ask the Admin. people to move it where it should go since I'm not sure where to place it.
In 2019 I quit my job to care for my wife who was given less than a year to live. I took my 401K, paid off our bills, paid Uncle Sam his share, completed a solar build on my camper and helped my wife with the one item on her bucket list; make a two week trip to prove the solar setup worked on our camper and to visit people she wanted to see before she passed away.
After we returned from our trip I began to research an electric trike when I had nothing else to do around the house. About a month later I began to do inventory of items I had left over from my solar experiments for my camper. I also purchased a DC motor with controller-throttle peddle/hand throttle and brake levers wired for brake lights. I also purchased six Mighty Max 12V 12aH batteries. The holidays were just around the corner so my experiment was set aside until after the New Year. Shortly after New Years my wife began to show signs of the cancer progressing and towards the end of February 2020 she lost her battle with it.
By the beginning of April 2020, my funds to live on were rather low and the Covid lockdown began. I wasn't able to return to the work force due to this. To save money, I moved into my camper, turned off all grid-tie items except water and began looking for a way to survive until I could return to work or reach the age of 62 when I could take an early retirement. This also meant I needed to find a way to live without my pickup to eliminate around 3K a year of insurance payments. I had about four months before my insurance was due again so that was my deadline.
A few weeks later I discovered there were several odd job people around my area needed completed. All meant I would have to be around possible Covid infected people but being a rather healthy person I was not worried about that. Over the next seven or eight months I made enough to keep my pickup on the road. I did other odd job throughout the winter until February 2021. During the weekend before the 'Big Freeze' hit Texas and southern Louisiana I was helping neighbors prepare for the freeze when I began to have sever chest pains. Almost a year to the day after my wife had passed away I was checked into the hospital and spent the big freeze in hospital/doctors care. Six weeks after my release I was checked back into the hospital with my second heart attach and this time they fixed the problem with my heart. I was informed that the hospital had informed the Social Security Admin that I wouldn't be able to return to work just days before my 62nd birthday. With warmer weather just around the corner and me feeling like a new man, I began to line up new odd jobs to keep me with enough money to keep my pickup on the road. The only problem was there wasn't enough odd jobs for me to do this year. With the government still under lockdown, I began working with the Social Security Admin to get my SSI check coming, over the phone. I've been told it can take as long as two to three years to get my first check. Here it is the end of August 2021 and still no check. It is now time to begin the old solar trike project again.
Now comes the time I ask for a really big favor from everyone on this forum. I have two 255 watt poly solar panels, one Renogy 40A charge controller, six Mighty Max 12V 12aH batteries, the 24V 500watt 27.4 amp 2500 max RPM motor with all the items listed above that came as a matched set. This will all connect to a 26 inch rear wheel using a 11 tooth sprocket on the motor and a 48 tooth sprocket on the wheel. Weight of the trike will be around 100 to 150 lbs. max and have a 200 lb. man riding it. I'm not sure if the info on the trike is really needed but I have added it to make sure everyone had all the info I had to offer. I don't plan on running this at max speed, somewhere around half throttle is my expected max cruise speed. Does anyone have a formula that could help me estimate the best performance of power generated, expected charge/draw of battery during use and what I can expect over the course of the day? I may not be asking this correctly. I plan for the solar panels to be permanently mounted to the trike and I have very few trees to block sunlight. I know I need to upgrade my batteries to two 12V lithium batteries in the near future. My long term goal for this is being able to make 30 miles round trip in one day, one or two times a week. Short time goal is to present this to the school board and teachers as a STEM project for the areas local high school. I would like to get the students involved in the Solar Car Challenge that could lead to some of them getting college scholarship to one of the many colleges that are involved in this type activity. The local college is about to open a new STEM building for teaching students. I believe STEM stands for Science, Technology, Education and Mechanics. Does anyone have any information that can help me reach my goal for a liquid fuel free form of transportation?
Thank you all in advanced for any help you may be able to offer.


Participation Medalist
Nov 5, 2019
Silicon Valley
the 24V 500watt 27.4 amp 2500 max RPM
This is really reaching but let me assume you'll use 50% of the 500W of power (250W is about 1/3HP!)
I will also guess you'll travel at 15MPH (so a 30 mile trip takes 2 hours).

So 250W / 25.6V = 9.8A
9.8A x 2H = 19.6Ah

Traveling at 10MPH, same power use would be 9.8A x 3H = 29.4Ah

two 255 watt poly solar panels, one Renogy 40A charge controller
This is going to be over 100lbs alone!
510W / 25.6V = 19.9A (almost 20Ah recharge per hour!)


New Member
Aug 22, 2021
I applaud your willingness to inspire young people with solar/STEM technology as well trying to make the best of a very difficult situation.

If I understood your post correctly, you have a three wheeled electric bicycle (trike)? I’m also not sure what you are trying to accomplish? An outline of your goals and a description of the trike (i.e. manufacturers website) may be helpful as well.

It’s hard to provide any specific suggestions without a better understanding of your goal(s). Generally speaking, my interests in bikes and solar, have led me across a few resources that might be helpful. I would also add that a lot of people are experimenting with solar powered cargo bikes and bikepacking.

Suggested Searches:

solar cargo bike
solar cargo bike forum
solar bike
trike with solar panel (see google images for examples)

Suggested Websites:

Grin Technologies (

YouTube Channel:
  • Primer on Solar eBike Systems
  • Playlist: Suntrip Build Vlog
  • The company founder’s “bike” built for this event may give you a few ideas as well as their profile of additional participants.
  • I think the last video is a summary of what worked and what didn’t. Note their comments as to camping with good southern exposure to obtain a sufficient charge in the morning.
Luna Cycles (

The company founder is endlessly experimenting and one of his projects was hot-rodding a trike.

YouTube Channel:

Search on “tricycle” – several interesting points about transmitting power to the wheels.

Burley Trailers (

Possible solutions for hauling and/or mounting panels.

  • Endless Sphere
  • Electric Bike Reviews


New Member
Oct 27, 2020
First of all, thank you MisterSandals for the different formulas. As you may be able to tell, I have a very small understanding of solar.

Second, my total spendable allowance since April 2020 has been $160.00 per month, MAX! With the help of friends and neighbors I have been able to have at least one meal a day for the whole time till present day. Doing odd jobs has allowed me to keep my pickup with insurance and a little gas to keep it running so I had a way of keeping it for needed trips to town and doctors appointments. My phone is a prepay type and cost me just $20.00 per month for unlimited talk and text. My water is the only bill I have to pay and I limit its use to keep it to an amount I can afford to pay each month. My internet is provided by the local Burger King and Walmart. If I am in town for whatever reason, I try to plan an extra hour or two for my research, so I don't have much time to spend researching during my trips. I guess you could say I am experiencing a mild case of SHTF.

Third, this is for my transportation until I can get my Social Security check coming from the government for my early retirement. I only have a personnel desire to have the bonus of steering young people in my area to a better education and possibly not to depend on a job at Burger King, McDonalds and like businesses. The main money maker in my area is farming and crawfish, not much hope for young people not raised in a farming family. I had to find work that kept me away from home and family for weeks and months at a time. Not good for the family unit and I want more for the future generations in my area. This could be the lead to that chance for some of these young people.

Fourth, over the years I have built several motorcycle frame for people who owned per 1960 motorcycles. That was during a time when motorcycles were titled on the motor, not the frame like present day motorcycles are. The trike is of my own design and can be modified at my will during the building process. Which basically means all parts will be cut, fitted and held in place by a jig designed for that purpose, before and until all welding is completed. The trike is of my own design and no website is available for you to look at. My apologies for that.

Fifth, this was me looking to see if it may be worth spending about six months of my living expense that I have in savings to purchase two used solar panels that were purchased from the same pallets as my two panels. It would also allow me to purchase two used 12V 100A lithium batteries that have been sitting in my neighbors garage on a shelf for the past year to use with this project. One added bonus is he will give me a 60A Renogy charge controller with the purchase. He liked my idea of solar power for a camper and wanted to do a little experiment of his own back during the time I started my first attempt at solar. He didn't like the idea of power management (thinking solar would be a cure all for electric) so he scraped his experiment and shelved everything he purchased. I got lucky with my third solar design and it worked for what I needed to do at the time, I later upgrade to my present setup. My welder will run off a generator unless one of my neighbors will allow me to trade my services for the use of their electric power for a week or two.

Finally, I put in a garden this past spring to grow my own food. I am not one who likes to depend on others for my meals or living. My garden has allowed me to eat and canning of vegetables so I will be able to eat through the winter and maybe until my next crop begins to produce fruit for me to eat next year. This would allow me to use part of my saving for insurance for my pickup if I can grow more crops next year for my meals.

So, I need to travel nine miles one way to where I purchase my medication each month and fifteen plus miles one way to make my doctors appointments. One doctor is more than 35 miles from me and I need my pickup for that once every three months at present time. I have a neighbor who took me to my last appointment with the doctor 35 miles from me because I didn't have the gas to make it on my own. I don't like to depend on anyone except for myself to live but sometime you have to swallow your pride just to survive. This is one time I decided to swallow my pride to reach a goal of self dependence. I guess you could say my ultimate goal is survival, with the added bonus of maybe helping young people in the process.


Solar Enthusiast
Feb 22, 2021
A few thoughts

I agree that 100 to 150 pounds for your project trike is probably not realistic - We have a commercially made fat tire electric trike with no solar panels, an all aluminum frame, a commercial 48 volt, 12 AH battery and it weighs pretty close to 100 pounds. It will do 30 miles and has a top speed of 18 mph. Cost was $2,200

You won't get that much power from solar while riding your trike, but it will add lots of weight and bulk - I think you would be better off to make the trike as lean and light as possible and if you can't recharge it from commercial power, use a fixed mount solar array that you don't have to carry with you for recharging while it's stationary. Keeping the trike as light as possible will also be a huge benefit for times when you run out of power and have to pedal it to your destination - That will happen and it won't be easy to pedal. Just going a mile or two will require lots of effort, maybe more than you're capable of?

Adding weight to a pedal only trike not designed to haul cargo will probably have you eventually needing repairs to wheels and other parts. In normal use, without the extra weight you're planning to add, such a trike would very seldom ever be ridden 30 miles, let alone once or twice per week. I don't think you're going to get long term use from a modified pedal trike that you're planning on using for hundreds of miles per month. A heavier trike would need more robust hubs, wheels, spokes and other components - I just don't see your much heavier modified trike lasting very long. You would probably be doing very well to get a full years use out of a commercially made electric trike riding it 3,000 miles per year and that's what two 30 mile trips each week would add up to

Does your trip involve sidewalks, or would you be having to ride on the roads with other vehicular traffic? That would not be very safe and you might end up back in the hospital again or worse

Before you commit to spending a large chunk of your meager resources to this project, I would advise you to carefully consider how practical this project actually is - It sounds good on paper, commuting for free 3,000 miles every year, but the reality of making it work would involve many expensive modifications and it may not prove all that practical, nor last you very long

Last - $3K per year for insurance on a pick-up truck is just . . . . ridiculous! I have a diesel motor home that I have full coverage on valued at $30K and I pay $500 per year to insure it. If you had an older vehicle which you owned outright, you could carry liability only insurance on it for a tiny fraction of that $3K and you would have a way to get around rain or shine - Compared to your trike, that's 'practical'

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New Member
Oct 27, 2020
Thank you for a little insight into my design and weight issues. I've been looking into just these items when I took time to do weight estimates. I do need more research on suspension items. Estimated weight with panels is going to be around 350 to 375 or more not to mention my 200 lbs. Motor upgrade to allow for this weight and torque needed to move it around 10 mph will be needed. I am going to have to research a little more before beginning my build.

I have already talked to an old high school buddy who had owned a motorcycle dealership. He says he has some old motorcycles that I can rob for parts. Some were made for motorcycles that weighed around 400 to 450 lbs. and would carry a person over 200 lbs. He says he has one that has a good swing arm and wheel but needs new rubber and may need new bearings. He also says he may have a couple of front wheels in the same shape that should solve the wheel/tire problem. He also has ideas how to incorporate them into my suspension system on the front. He says we can get shocks for cost from his son-in-law and maybe he will even spring for the rubber and bearings at cost. Frame isn't a problem since I know how to design and build a frame to support the weight this will have on it (around 150# to 200# for solar panels, frame around 175#). I will need to think about a 48V system and a motor with a couple of HP more than I have now. I think I may have to upgrade the panels to 3 or 4 each 410watt mono panels with the new to me 60A charge controller. Still about the same weight as the 255watt panels and 40A charge controller.

As for the insurance, my 1995 half ton pickup would cost a little over $800.00, my 2010 half ton pickup is a little over $1,500.00 per year, and my 2020 one ton daily driver is just a little over $2,950.00 and all these prices are for liability with un-insured motorist. The 1995 is needing several grand to complete the restore, the 2010 needs $3,500.00 to repair the computer and the 2020 diesel dually needs nothing to be my daily driver. The $30K motor home is not considered a daily driver in my state and therefore wouldn't be more than my 1995 if it were running, even if the motor home was less than three years old and had to have full coverage on it. On the other hand, my 2020 $80K custom dually that is fully paid for is considered a daily driver and therefore does cost a little under $3,000.00 with 2K deduction to insure for liability with uninsured motorist coverage per year. If I would have had ticket/s or an accident on my record in the past ten or fifteen years the cost would be close to the $4K mark in my state. The good thing about the 2020 is, we had zero percent financing, free lifetime oil change, free lifetime wash and wax and a few other for lifetime items, guarantied and in writing before I would agree with the purchase. I also have the ability to unhook from my camper if I need to go to the store or for other reasons. My 26 FT. camper only costs me $125.00 per year with zero deductible for full coverage whether it moves or not. I'm just thankful I didn't have to insure my pickup in the state of Tennessee, it would have cost me over $6K like a friend of mine has to pay for his 2018 dually for liability only.

What IS ridiculous is you trying to compare a vehicle that the insurance companies categized as a recreational vehicle that THEY say will only be driven a few times per year (regardless of how much you do drive it) to a vehicle that the insurance companies categized as a vehicle that will be driven several times per week. That difference alone would cause a major cost difference for insurance no matter what insurance company you may use. My pickup is worth $50K more than your motor home which would also add greatly to my insurance cost over what you pay. Your vehicle is made to travel to a place and park for a few days then return home. Mine is made to pull or haul more weight than yours is able to after adding all the equipment inside of it that it has to have to be classified as a motor home. I personally have pulled a trailer with four full-sized vehicle loaded on the trailer for more than 500 miles to earn extra money to make payments on my pickup. Yours is probably only rated for one mid size vehicle to be pulled behind it. I can list other differences but you can see the point I am trying to make. Two different vehicles for two different purposes equals two different insurance prices. Mine just happens to cost six times what yours cost.

Again, thank you for all the info regarding the solar vehicle build idea. It has given me plenty to think about, research and find items to resolve these issues. I really do appreciate your insight plus hands on knowledge and will enjoy the challenge of resolving all the issues you pointed out. I look forward to any other input you may have to offer in the future.

On a happier note, Uncle Sam finally sent me my payment along with back payments from when I began my request for early retirement. I also received a letter stating my regular payments will begin starting next month. That means I now have some extra to spend on any upgrades I find to resolve issues with the solar vehicle build and can pay for insurance on my pickup. This just went from my daily transportations project to a project to catch the eye of students to explore for future education possibilities. I still would like to build it to withstand a 1,500 to 2,000 miles worth of travel with minimal repairs needed. Just to give me some idea of what may need to be done to reach the requirements set up by the Solar Car Challenge and to help me provide guidance to young people that may decide to take on a project somewhat like I am trying to build.

I still would like any thoughts regarding possible problems I may encounter with this solar vehicle project from you or anyone who may read this forum post. This is not a one person type project and the Solar Car Challenge is designed to be a multi person project. With all people researching different items, getting feedback from different people then finding the solutions to the problems found during group discussions. This is the same thing I hope to have here with a common goal by all people in this group participating to bring up problems and solutions to any problem that may come up. The only difference is I am the only one doing the work and the only one paying for the build. Everyone else is the problem finders and I hope assisting me in problem solving. I do know the budget is very small but that is just another problem I will need to solve.

Thanks for any and everyone who offers comments and possible solutions to problems.