Parts List & Overview
Parts List & Overview
A DIY solar repeater can be built for $80 - $130 using commodity parts. This build creates a weatherproof, autonomous LoRa mesh repeater powered entirely by solar with enough battery reserve to ride through multiple cloudy days.
Full Parts List
| Component | Recommended Option | Cost | Notes |
|---|---|---|---|
| LoRa node | Heltec V3 or Heltec V4 | $20 - $35 | V4 preferred for solar builds (built-in solar input); V3 works with external charge controller |
| Alternative node | RAK WisBlock (RAK4631 + RAK19007) | ~$35 | Lower power draw; more expensive but nRF52840 runs cooler |
| Antenna | 5 dBi fiberglass omni | $12 - $20 | RAK 5.8 dBi fiberglass is a community favourite at $30 - $40 |
| Coax pigtail | SMA pigtail, 15 - 30cm | $3 - $5 | Match connector type to your node (SMA or RP-SMA) |
| Solar panel | 6W 6V monocrystalline | $15 - $20 | 6V panel works directly with TP4056 or CN3791 |
| Battery | Samsung 35E 18650, 3500mAh | $10 | Buy from reputable source - most Amazon 18650s are counterfeit |
| Charge controller | CN3791 MPPT module | $3 - $5 | More efficient than TP4056; better for variable solar; supports 6V input |
| Enclosure | Zulkit IP65 150×100×70mm | $12 | Hinged lid; 2 cable glands included |
| Cable glands | PG7 (thin cables) or PG9 (coax) | $3 - $5 | For antenna pigtail and solar wires entering enclosure |
| Mounting hardware | U-bolt + hose clamps or pole mount | $5 - $8 | Stainless steel preferred for outdoor longevity |
| Desiccant | Silica gel packs 5g | $2 | Place inside enclosure; replace annually |
| Sealant & misc | Silicone sealant, zip ties, heat shrink | $5 | Seal cable glands and any penetrations |
Total estimated cost: $80 - $130 depending on component choices.
Power Budget
Before building, verify the solar panel and battery are adequately sized for your location and expected traffic.
| Parameter | Value | Notes |
|---|---|---|
| Average current draw | 20 - 40 mA | Typical repeater with moderate traffic |
| Daily energy use | ~2.22 Wh/day | 25mA × 3.7V × 24h |
| 6W panel, 2.5 peak sun hours, 70% efficiency | 10.5 Wh/day | 4.7× margin over consumption - adequate for year-round North Dakota |
| Single 3500mAh 18650 capacity | 12.95 Wh | 3500mAh × 3.7V; covers ~5.8 days with no solar |
Build Overview
The build has four main stages:
- Flash firmware - flash MeshCore Repeater variant onto the node before sealing it in the enclosure
- Wire the power system - solar panel → charge controller → battery → node
- Weatherproof the enclosure - cable glands, sealant, desiccant
- Mount and aim - antenna orientation, solar panel angle
See the Assembly Guide page for step-by-step wiring and mounting details.