How to Build a Solar Powered RC Car: Parts, Wiring, Realistic Output
A solar-powered RC car uses a small solar panel to drive the motor directly or, better, to charge a battery that powers the car. The practical design is: solar panel → charge controller → small LiPo or Li-ion battery → motor driver and receiver or microcontroller → motor and steering servo. A panel that fits on a 1/10 car gives only a few watts in full sun, so expect slow driving or long charging, not basher speeds. Here are the parts, the wiring and realistic numbers.
By Kyle HilsonUpdated: October 20263 min read
Two designs
| Design | How it works | Pros | Cons |
|---|---|---|---|
| Direct drive | Panel powers the motor directly | Simple, no battery | Stops in shade; weak acceleration |
| Battery buffer | Panel charges a battery through a controller; battery runs the car | Drives in shade; normal electronics work | More parts; charging takes time |
The battery-buffer design is the one to build if you want an RC car that drives reliably.
How much power does a solar panel give?
Full sun delivers roughly 1000 W per square metre, and small hobby panels convert about 15–20 % of it. A panel of 20 × 30 cm (0.06 m²) therefore gives roughly 9–12 W at best, and much less when angled, cloudy or warm. A brushed 1/10 car motor can draw well over 100 W at full throttle. So:
- Direct drive works for very light, slow cars with small motors.
- With a battery, an hour of good sun on a 10 W panel puts about 5–8 Wh into the battery after losses, enough for a short run of a small car.
- Bigger panels add weight and catch wind; keep the car light.
Parts list (battery-buffer design)
| Part | Choice |
|---|---|
| Solar panel | 5–10 W, 6 V or 12 V (match the charge controller) |
| Charge controller | Solar charge module for the battery chemistry (e.g. 1S Li-ion/LiPo charger board with solar input) |
| Battery | 1S or 2S Li-ion/LiPo with protection circuit |
| Motor driver | Small brushed ESC or TB6612/DRV8833 driver board |
| Control | Hobby receiver + transmitter, or ESP32/Arduino with Bluetooth/Wi-Fi |
| Steering | Micro servo |
| Motor | Efficient small brushed motor with low gearing |
| Chassis | Light plastic or 3D-printed frame |
Wiring
- Panel output to the charge controller’s solar input (watch polarity).
- Controller’s battery terminals to the battery (with protection circuit).
- Battery to a power switch, then to the motor driver/ESC and a regulator for the logic (5 V / 3.3 V).
- Receiver or microcontroller signals to the driver and the steering servo.
- Add a fuse on the battery line; tie all grounds together.
Microcontroller control, code and fail-safe are covered in RC car circuit board and controlling an RC car with a computer.
Tips
- Keep weight down: every gram costs energy.
- Low gearing and efficient bearings matter more than motor power.
- Tilt the panel toward the sun when parked for charging.
- Protect the panel: a clear plastic cover prevents cracked cells in crashes.
- For school projects, measure voltage and current in sun and shade and compare.
FAQ
What are the key components for a solar RC car with a microcontroller?
Solar panel, charge controller, battery, voltage regulator, microcontroller with radio (e.g. ESP32), motor driver, motor and steering servo.
Can a solar panel power an RC car directly?
Only very light, slow cars, and only in full sun. A battery buffer is far more practical.
How fast is a solar RC car?
Usually slow; with a battery buffer it can drive like a small normal RC car for short runs.
Can I add solar to my existing RC car?
You can use a panel and charge controller to recharge its battery between runs; it won’t power the car while driving at speed.
More on this topic: the complete RC Cars guide covers the basics behind this article.
About 20 years in RC. Mostly boats in the NAVIGA Mini Eco Expert class, with many self-made parts; also a King Motor Baja 5B, a home-built electric plane, home-built nitro planes he has flown, and an RC helicopter. More about SwellRC
