Harbor Breeze Solar Node (~$10 enclosure, ~$65 total build)
Overview
The Harbor Breeze Solar Node converts a $10 - 15 Harbor Breeze 60-lumen solar LED floodlight (Lowe's item #SL1832) into a weatherproof, solar-powered mesh node. The floodlight already includes a small solar panel (rated ~0.6 W per the Lowe's listing; a rough estimate of ~90 mA at 5 V), an 18650 cell (the listing includes a 3.7 V ~1500 mAh 18650), a charge circuit, and a weatherproof enclosure - the hard parts are done for you. (Prices and specs as of 2026-06-08.)
Total cost including radio: approximately $60 - 70 (as of 2026-06-08; the total tracks the volatile RAK4631 street price). Enclosure + solar hardware alone: $10 - 15.
Bill of Materials
All prices are commodity/street prices as of 2026-06-08 and will vary; recompute the total if the RAK4631 price changes.
| Item | Cost |
|---|---|
| Harbor Breeze 60LM Solar LED Light (Lowe's #SL1832; includes a ~1500 mAh 18650) | $10 - 15 |
| RAK4631 WisBlock Core (nRF52840 + SX1262) | $18 - 24 (street price, varies) |
| RAK19007 WisBlock Base Board (USB-C + JST) - $9.99 per store.rakwireless.com | $9.99 |
| 915 MHz LoRa Antenna 2 dBi SMA whip (typical commodity price) | $5 - 10 |
| u.FL to SMA Bulkhead Pigtail (~10 cm; typical commodity price) | ~$5 |
| 18650 cell (optional - a ~1500 mAh cell is already included; only needed for a higher-capacity replacement or if depleted) | $5 - 10 |
| Misc: heat-shrink, silicone sealant | ~$5 |
| Total (approx., as of 2026-06-08) | ~$60 - 70 |
Assembly Overview
- Remove the back cover of the floodlight housing.
- Remove the LED assembly and cut existing wires near the board.
- Drill a 1/4″ hole through the housing for the SMA bulkhead connector.
- Install the RAK WisBlock base board and core module inside the housing.
- Wire the battery: red = positive (+).
- Wire the solar panel to the RAK19007 solar charge input header - verify the exact header label and polarity against the RAK19007 datasheet before connecting.
- Weatherproof all cable entry points and the SMA hole with silicone sealant.
- Reinstall the back cover.
Critical Warnings
- Keep the solar input within the RAK19007's rated charge-input limit. Confirm the exact maximum solar/charge input voltage against the current RAK19007 datasheet before connecting; as a conservative ceiling, do not feed more than ~6 V into the solar input. The Harbor Breeze panel is rated ~0.6 W trickle charge. Do not substitute a higher-voltage panel.
- Verify solar wire polarity before connecting to the charge-input header. Reverse polarity will damage the charge circuit.
- This panel provides trickle charge only - not suitable for high-duty-cycle backbone repeaters. Nodes that transmit frequently will discharge the battery faster than the panel can recharge it.
Best For
- Fence lines and yard boundary sensors
- Low-traffic area coverage (parking lots, fields, trails)
- Budget-conscious deployments where AC power is unavailable
Not recommended for high-traffic backbone repeaters or nodes that need continuous uptime.