On this page
The best solar panel for low light under 40 starts with the SwitchBot panel, which the listing states offers double charging efficiency in low light for SwitchBot Curtain 3. We compared 3 solar panels for low light by charging efficiency, build and features, using only what each listing publishes. The BONAI and Aocoray are general-purpose panels for USB charging.
SolarKitHQ earns a commission when you buy through links on this page, at no extra cost to you. As an Amazon Associate I earn from qualifying purchases. Affiliate disclosure.
Quick picks
Best Low Light SwitchBot Solar Panel Charger: Double efficiency, 3 hours, 1 year Check price on Amazon
Best 9W BONAI 9W Solar Panel: 9W, 2 pack, IP65 Check price on Amazon
Best Mini Aocoray Mini Solar Panel: 6W, mini, monocrystalline Check price on Amazon
The picks
| # | Product | Solar Score | Buy |
|---|---|---|---|
| 1 | BONAI 9W 2-Pack Panel | 9.7/10 | Buy on Amazon |
| 2 | SwitchBot Solar Panel Charger | 9.6/10 | Buy on Amazon |
| 3 | Aocoray 6W Mini Panel | 9.4/10 | Buy on Amazon |
BONAI 9W 2-Pack Panel
Two 9W ETFE panels with 10-foot USB-C cables and micro USB adapters for outdoor cameras, phones and all DC 5V devices.
Pros
- 9W per panel, the highest wattage of the camera panels here, with steadier cloudy-day charging claimed
- Stated operating range of -4°F to 176°F, the widest here
- IP65 rating with ETFE encapsulation
- 10-foot USB-C cables, wall brackets, screw packs and USB-C to micro USB adapters in the box
Cons
- No conversion efficiency figure is stated
- 11.4 by 7.5 by 1 inch is larger than the 5W camera panels, so check the mount spot
- The 99% compatibility claim names no device list
- Brackets, adapters and screw packs mean more parts to mount than a single-piece panel
Detailed Review
The listing states a two-pack of 9W panels with ETFE encapsulation, an IP65 rating, 10-foot USB-C cables, USB-C to micro USB adapters, wall brackets, screw packs and quick start guides. It gives an operating range of -4°F to 176°F, a 5V output for outdoor cameras, smartphones and other DC 5V devices, and a 12-month warranty with 24/7 technical support. The maker claims 99% compatibility and more stable power in cloudy conditions, and the spec table lists 9 watts maximum power, the per-panel figure.
Who it's for: owners who want the strongest small panel here for a camera or 5V device that sits out in rough weather. Who should skip it: anyone who wants the smallest panel on the wall, since these are the largest of the camera picks.
Its Solar Score of 9.7/10 comes from performance 32/35, build 21/25, value 21/25, safety 7/10 and warranty 3/5: 84 of 100 points, placed on our 9.2 to 9.8 scale.
Key Specifications
| Set | 2 x 9W, 5V |
|---|---|
| Weather rating | IP65 |
| Temp range | -4°F to 176°F |
| Panel size | 11.4 x 7.5 x 1 in |
Figures as published on the retailer listing, collected 20 October 2026. Performance figures are manufacturer rated.
Safety and Warranty
What this listing states. IP65 rating with ETFE encapsulation stated, so safety scores 7 of 10. 12-month warranty and 24/7 technical support stated. It does not say everything a buyer needs, such as who pays return shipping, so warranty scores 3 of 5. See How We Pick.
Panels make voltage in daylight. Keep connectors covered until you connect them, check the panel's stated open circuit voltage and current against your controller or power station input limits, and use cables rated for the current. Roof and permanent mounts belong to a qualified installer.
This is general buying information, not professional advice. Follow each product manual and local rules, and see our Safety Disclaimer.
SwitchBot Solar Panel Charger
A solar panel for SwitchBot Curtain 3, low light charging, 3 hours sunlight.
Pros
- Low light charging
- 3 hours sunlight
- one-year warranty
- For Curtain 3
Cons
- Only for Curtain 3
- No battery
- White only
- 5V output
Detailed Review
The listing states double charging efficiency in low light, and that 3 hours of sunlight provide unlimited range for Curtain 3.
The listing states a one-year warranty and an integrated suspension bracket for direct connection to SwitchBot Curtain.
Its Solar Score of 9.6/10 comes from performance 33/35, build 22/25, value 21/25, safety 0/10 and warranty 0/5: 76 of 100 points, placed on our 9.2 to 9.8 scale.
Key Specifications
| Output | 5V |
|---|---|
| Warranty | one-year |
| Use | Curtain 3 |
Figures as published on the retailer listing, collected 21 October 2026. Performance figures are manufacturer rated.
Safety and Warranty
What this listing states. No UL, TÜV or IEC listing and no weather rating is stated, so safety scores zero. No warranty term, so warranty scores zero. See How We Pick.
Panels make voltage in daylight. Keep connectors covered until you connect them, check the panel's stated open circuit voltage and current against your controller or power station input limits, and use cables rated for the current. Roof and permanent mounts belong to a qualified installer.
This is general buying information, not professional advice. Follow each product manual and local rules, and see our Safety Disclaimer.
Aocoray 6W Mini Panel
A compact 6W 5V USB solar panel in monocrystalline silicon for phones, fans and lanterns.
Pros
- Compact 11.8 by 5.7 inch size
- USB output for phones, fans and lanterns
- Water-resistant and scratch-resistant build
- Light at 0.16 kg
Cons
- Admits it slows or stops when sunshine is weak
- No warranty term is stated
- No efficiency percentage is stated
- Single USB output only
Detailed Review
The listing states a 5V 6W mini USB solar panel in monocrystalline silicon, 11.8 by 5.7 by 0.5 inches and 0.16 kg, for phones, power banks, cameras, fans and camping lanterns. It states a water-resistant and scratch-resistant build for long-term outdoor use. The notes admit the panel works more slowly or stops working when sunshine is weak. No warranty term is stated.
Who it's for: campers and hikers who want a pocket-size USB panel for small electronics in good sun. Who should skip it: buyers who need stated output in weak sun; the listing warns it slows or stops.
Its Solar Score of 9.4/10 comes from performance 23/35, build 19/25, value 20/25, safety 4/10 and warranty 0/5: 66 of 100 points, placed on our 9.2 to 9.8 scale.
Key Specifications
| Power | 6W, 5V |
|---|---|
| Output | USB |
| Size | 11.8 x 5.7 x 0.5 in |
| Weight | 0.16 kg |
Figures as published on the retailer listing, collected 20 October 2026. Performance figures are manufacturer rated.
Safety and Warranty
What this listing states. Water-resistant and scratch-resistant build stated, so safety scores 4 of 10. No warranty term, so warranty scores zero. See How We Pick.
Panels make voltage in daylight. Keep connectors covered until you connect them, check the panel's stated open circuit voltage and current against your controller or power station input limits, and use cables rated for the current. Roof and permanent mounts belong to a qualified installer.
This is general buying information, not professional advice. Follow each product manual and local rules, and see our Safety Disclaimer.
As an Amazon Associate I earn from qualifying purchases.
Compare the picks
| Panel | Solar Score | Battery | Voltage | Warranty | Amazon |
|---|---|---|---|---|---|
| SwitchBot Solar Panel Charger | 9.6/10 | No battery | 5V | Not stated | View on Amazon |
| BONAI 9W Solar Panel | 9.7/10 | Not stated | Not stated | Not stated | |
| Aocoray Mini Solar Panel | 9.4/10 | Not stated | 5V | Not stated |
Panel details as published on each listing, collected 21 October 2026.
How we scored them
The Solar Score weighs charging efficiency and low light performance, build quality, value, safety, and warranty. All 3 are solar powered. How we pick explains the weights.
| Product | Solar Score | Perf. /35 | Build /25 | Value /25 | Safety /10 | Warranty /5 |
|---|---|---|---|---|---|---|
| SwitchBot Solar Panel Charger | 9.6 | 33 | 22 | 21 | 0 | 0 |
Scores run from 9.2 to 9.8: each product’s point total is placed on that range, so more points always means a higher score.
How to choose the best solar panel for low light under 40
Check low light performance
The SwitchBot lists double charging efficiency in low light. The listing states just 3 hours of sunlight provide unlimited range for the Curtain 3. That is the key feature for low light use.
Look at panel output
The BONAI lists 9W. The Aocoray lists 6W. The SwitchBot lists 5V output for Curtain 3. Match watts and voltage to the device you charge.
Confirm compatibility
The SwitchBot only works with SwitchBot Curtain 3rd Gen. The BONAI is a 2-pack with a 10FT USB-C cable. The Aocoray is a mini USB panel. Check your device voltage before buying.
Understanding solar panel specs
Solar panel output is measured in watts. The BONAI lists 9W. The Aocoray lists 6W. The SwitchBot lists 5V output for Curtain 3.
The SwitchBot panel charges Curtain 3 directly. The BONAI 2-pack gives a spare panel for another device. The Aocoray mini panel suits small devices.
Voltage must match your device. The SwitchBot is 5V. The Aocoray is 5V. Using the wrong voltage can damage your device. Check the label on your device before buying.
Installation and positioning
Position the panel where it gets direct sun. The SwitchBot has an integrated bracket for the Curtain. Angle the panel toward the sun for best charging.
In the northern hemisphere, face the panel south. In the southern hemisphere, face it north. Tilt it at roughly your latitude angle. That maximizes sun exposure through the year.
What the REUSED products offer
Two of the 3 panels here also appear in other SolarKitHQ articles. Their cards keep the short text from those articles. That is why the BONAI and Aocoray have shorter descriptions. They are still ranked by score like the others.
The BONAI 9W is a 2-pack with 10FT USB-C cable. The 9W output suits charging phones and small devices. The IP65 code is stated for the BONAI. The 2-pack gives you a spare or lets you charge two devices.
The Aocoray 5V 6W is a mini panel. The monocrystalline cells are efficient for the size. It suits small projects and DIY use. The USB output works with most 5V devices.
Value under $40
All 3 are under $40. The SwitchBot works only with the Curtain 3. The BONAI and Aocoray are general-purpose panels.
Consider what you are powering. For a SwitchBot Curtain, only the SwitchBot panel works. For USB devices, the BONAI or Aocoray are better.
Low light charging explained
Standard solar panels need direct sun to charge well. Low light panels use more efficient cells or larger surface area to capture diffuse light. The SwitchBot lists double efficiency in low light. The BONAI and Aocoray listings state no low-light efficiency figure.
Low-light performance matters most when sun is weak; among these picks, only the SwitchBot listing states a low-light efficiency claim.
Maintenance and longevity
Clean the panel monthly with a damp cloth. Dust reduces efficiency. Check the cable for wear. The SwitchBot lists a -20C to 60C temperature range. That covers most climates. The BONAI lists IP65.
The SwitchBot listing states no additional maintenance is needed. Check the cable for wear and keep connections clean.
Comparing the panels
The SwitchBot is made for Curtain 3 with low light charging. The BONAI is a 9W 2-pack with a 10FT USB-C cable and IP65. The Aocoray is a 5V 6W mini panel with monocrystalline cells.
Choose the SwitchBot for Curtain 3. Choose the BONAI for a 2-pack with a cable. Choose the Aocoray for a mini panel.
Final recommendations
For SwitchBot Curtain 3 users, the SwitchBot panel is the only choice. For general USB charging, the BONAI 9W 2-pack offers a spare panel. For a mini panel, the Aocoray 5V 6W suits small devices.
All 3 are under $40. All are solar powered. Pick the one that matches your device and your climate.
Troubleshooting common issues
If the panel does not charge, check for shade. Even partial shade can drop output significantly. Clean the panel. Check the cable connection. Make sure the device is compatible with the panel voltage.
If the panel does not power the device, check that the voltage matches. The SwitchBot is 5V and the Aocoray is 5V. Check the connector type. The BONAI uses a USB-C cable.
If charging is slow, check for shade and clean the panel. The SwitchBot lists double efficiency in low light, but it still needs light to charge. Place the panel where it gets direct sun.
Seasonal considerations
Solar panels produce less in winter. Shorter days and lower sun angle mean less energy. The SwitchBot low light panel helps, but it still needs some sun. In deep winter, you may need to charge the Curtain via USB as a backup.
Solar panels produce less in winter. Shorter days and lower sun angle mean less energy. The SwitchBot low light panel helps, but it still needs some sun. Place the panel where it gets maximum winter sun, typically facing south in the northern hemisphere.
Quick start guide
Unbox the panel and check all parts. For the SwitchBot, attach the bracket to the Curtain. For the BONAI, connect the USB-C cable. Place the panel in direct sun.
For the SwitchBot, set the upward tilt angle for direct sunlight. Let it charge before judging performance.
Warranty and support
The SwitchBot lists one-year warranty. Warranty for the BONAI and Aocoray: Not stated. A warranty matters for solar products because they sit outside in all weather. Choose a panel with a warranty if you can.
The SwitchBot support is via their app, per the listing. Keep your receipt. Take a photo of the issue if you need to claim.
Before you buy
- Check low light efficiency: SwitchBot lists double.
- Note the panel output: 9W for BONAI, 6W for Aocoray.
- See the voltage: 5V for SwitchBot and Aocoray.
- Confirm compatibility with your device.
Sizing Notes
- Install in direct sunlight for best charging.
- Match the voltage to your device.
- Clean the panel monthly.
Frequently Asked Questions
Which works best in low light?
The SwitchBot lists double charging efficiency in low light. It is designed for low light.
Which panel is a 2-pack?
The BONAI is a 2-pack with a 10FT USB-C cable and IP65.
Are they under $40?
Yes. All 3 are under $40.
Related guides
See all our solar panel guides.
