Learn why building a solar powered VW bus requires careful consideration of batteries and driving habits. As a bonus, we unveil a solar-powered scooter.
Fabricating my solar-powered VW bus required quite a bit of trial-and-error to achieve the power needed to push a heavy old van any sort of distance. This included replacing a lead-acid battery bank with LiFePo batteries (lithium iron phosphate) of much great capacity for extended range. I also needed to add more solar power to gather more sunlight. Unfortunately, I did not have time to run a crowd-funding campaign and was forced to come up with the money myself to procure these adjustments, but the show must go on!
Next, I fitted 192 Calb Cam72 Lithium-Iron-Phosphate batteries. These batteries increased my storage capacity by almost four times and reduced total weight by 200 pounds! Before, when taking it easy with 10 kilowatt-hour lead pack, I could travel 50 miles. Now, with 44 kilowatt-hours of storage and 200 pounds lighter, I will can inch toward the 200-mile range.
I go slow. 50 miles per hour is where wind resistance starts to really deplete energy. Also the bus is a 1973 and going much more than 60 feels a little hectic anyway. I consider the vehicle an RV; for my family, slowing down and connecting with nature is the primary aim.
Lithium-Iron-Phosphate Batteries Differ from Other Lithium Batteries
Lithium-iron-phosphate-based technology possesses superior thermal and chemical stability, which provides better safety characteristics than those of lithium-ion technology made with other cathode materials. Lithium-phosphate cells are incombustible in the event of mishandling during charge or discharge and they remain more stable if under- or overcharged. They can withstand high temperatures without decomposing. When abuse does occur, the phosphate-based cathode material will not burn and is not prone to thermal runaway. Phosphate chemistry also offers a longer cycle life.
I could have had about 66 kilowatt-hours of energy storage instead of just 44 kilowatt-hour for the same price weight and size. But, the LiFePo cells last significantly longer.
I made my decisions based primarily on safety: The LiFePo battery is actually much safer and more environmentally friendly than the lead-acid batteries I previously used. Without the need to vent the LiFePo pack, I can use my battery box vent system now to cool the LiFePo bank.
Secondarily, LiFePo batteries do not contain any heavy metals, such as lead, cadmium, or any other corrosive acids.
Lithium Iron Phosphates Are Definitely the Eco Choice
I used a BMS — battery management system — from Thunderstruck Motors. I recommend you visit their online store, because the company employs knowledgeable and helpful people.
The BMS system monitors every battery to ensure that, if a cell fails, it will be detected and won’t affect safety or harm any others cells.
Adding Additional Solar
I purchased 5,200-watt flexible panels from Jack Rickard of EVTV. I mounted these in an aluminum frame. The array weighs just under 70 pounds, and it should be quite easy to maneuver. For a 1,200-watts array using conventionally framed, glass-topped solar panels, we are looking at nearly 200 pounds.
I will have a nice, light 1,000-watt awning to keep me in the shade and 2,200 total watts of solar. My goal is to travel 200 miles and charge up in two days (previously, our experience was a 120 mile range and 30 miles per day solar input). I would like to hop between national parks and other American splendor silently and with very low impact. Comfort, space, and clean remote energy harvest — now that’s freedom.
I had talked about the test results of the lithium batteries as well as the result of adding another 1,000 watts of solar to the VW bus in the form of an awning. Maybe more importantly I was able to test the flexible, much lighter panels, for performance and durability. Check!
I’m happy the flexible panels worked out; they weigh 7 pounds, compared to almost 40 for a glass-framed panel. Time to phase out the glass….and the weight. Without the glass to worry about, the panels are safer too. Flexible panels have been advantageous on boats for years now and are making their way to RVs worldwide due to this lightweight, flexible and conforming design. The awning retracts during driving.
I was fortunate to make it to “burning man” this year with my wife. We took the Solar bus and had an amazing time.
Solar-Powered Scooter
I was thinking before we left for the Nevada desert that it would be fun to have a small electric vehicle to spin around the gathering with. The next day, a friend dropped off a scooter that he “thought I could do something with.”
“I can, and I will!” I replied. I added the four extra lithium cells from my bus project, so I added a 100-watt flexible panel on the front and headed to Black Rock City.
I didn’t have time to get a charge controller on the scooter. I thought it would take a long time to charge and figured I would just keep an eye on it. The storage turned out to be around 900 watt-hours. As it turned out, traveling on the flat desert, the scooter pulled just a few hundred watts. It turned out to be more juice than I could use! During the day, the juice went right back in.
I quickly realized that I had something special.
When I got home, I drove the solar-powered scooter 20 miles and saw it charge right back up in a few hours –what a form of transport!
I started ordering parts and built my own version of the scooter from the ground up, calling it the “Solarrolla.” It’s made out of an aluminum frame, has three wheels for stability, includes a 100-watt flexible solar panel, and comes complete with a waterproof Bluetooth speaker and phone holder and charger.
Everyone needs a “Solarrolla.” The scooter is a way I can offer the solar driving experience without all that is entailed with the something as large as the VW bus. I realized the scooter could replace motorcycles in sunny countries where pollution is a real problem. Also, the scooter is a viable source of energy for lights, music, cell phone charging, laptop use, and anything else electric.
Brett Belan lived off-grid in California for a decade before he and his family moved to Ashland, Oregon. There he co-founding Apparent Energy, an engineering company dedicated to improving our electrical systems. He builds electric vehicles and converted a 1973 VW bus to a fully electric, solar powered vehicle. He’s working on a project now called Solarrolla, a solar powered electric scooter. Find out more at Solarrolla.com. Follow Brett on Facebook and Instagram. Read all of Brett’s MOTHER EARTH NEWS posts here.
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