Solar Car

"Slant6" (slant-6)
06/23/2018 at 09:34 • Filed to: None

Design and build post in the works. We race in July.

Any questions you’ d like to see adressed in the larger article?

DISCUSSION (12)

Ash78, voting early and often > Slant6
06/23/2018 at 10:04

I’m getting a serious Citroen 2CV rat rod vibe from this, and I love it.

How does it handle all the hills? Is the race in a flatter area?

Slant6 > Ash78, voting early and often
06/23/2018 at 10:07

Ive been told it looks like a lot of things, but 2cv rat rod is a first.

We have yet to do extensive testing, but the race does go through mountains in southern Idaho and Oregon. Being based in the Appalachians though we have some good incline test spots.

BaconSandwich is tasty. > Slant6
06/23/2018 at 11:02

I’d love to hear some more technical details.

How much solar panel area? How efficient are the cells? How are the cells hooked up so that you don’t lose power if a single cell gets covered? What’s the drive train (I’m assuming DC motor of some sort? Any sort of battery pack? ) How’s the frame made? Total weight? What’s the estimated top speed? Why the choice in rims instead of something with a more aerodynamic profile? (I’m guessing those rims don’t weigh much?)

Slant6 > BaconSandwich is tasty.
06/28/2018 at 14:46

Per regulation we have 5 square meters of cells.

This is not my area of expertise but I’ve heard 24% thrown around in regards to cell efficiency .

The cells are arranged into 4 sub arrays so that shading in one area doesn’t shut down the whole array.

Drive train is two hub mounted brush less motors.

We have a battery pack, 900 81650s.

Frame consists of a carbon fiber chassis for most of it, with a chromolly roll cage for the occupant cell. The roll cage is designed to absorb 5gs.

Total weight should be around 800lbs and 1200 with two passengers.

Top speed around 75mph. Should be able to run off sun all day at 55 and we have about 300 miles of range at 55 on battery alone.

We do have plans to put aero wheel covers on the wheels. Having that shape out of solid aluminum would be pretty heavy.

BaconSandwich is tasty. > Slant6
06/28/2018 at 21:13

That’s really neat. For the 18650 cells, did you guys solder on the connectors/bus bars, or use some sort of screw on terminals? Also, which motor controllers are you using?

I wish I got to play with that kind of stuff when I was in school!

Slant6 > BaconSandwich is tasty.
06/29/2018 at 02:08

We bought a spot welder for the batteries but ended up using some problematic friction fit caps. The way we have them now is clamped with threaded rod in parallel as a row of like 150 cells.

We were planning on using Tritium Wavesculpter 22 motor controllers but after 2 days of troubleshooting couldn’t get them to work. We’ll be hooking up the tried and true Mitsuba controllers in the morning.

Its certainly a fun and enriching experience. Im a Furniture Design student and I designed the body of the car but also got to be heavily involved in motor controller troubleshooting. I'm learning things outisde of my area of relevant knowledge but its really fun and Im getting a lot out of it.

BaconSandwich is tasty. > Slant6
06/29/2018 at 08:18

That’s awesome. Some day I hope to make my own EV, for fun. Until then, I'm trying to learn as much as I can.

Slant6 > BaconSandwich is tasty.
06/29/2018 at 11:22

Its only getting cheaper. Im hoping to pull my own body from our molds that I can store until I can afford my own ev build.

BaconSandwich is tasty. > Slant6
06/30/2018 at 12:09

Any luck finding a new potentometer accelerator pedal?

Slant6 > BaconSandwich is tasty.
06/30/2018 at 21:39

Nope. Currently digging through a box of pots trying to get one to work in an old golf cart housing.

BaconSandwich is tasty. > Slant6
07/01/2018 at 00:29

BaconSandwich is tasty. > Slant6
07/18/2018 at 10:07

I thought of another question for you. Where do you guys get single solar cells, rather than a bunch stuck together in a module? I've only ever seen modules for sale. Also, once they are stuck on the car, are they covered with some sort of resin, or does each cell have it's own piece of glass/plastic to protect it?