Build a solar-powered node (Arizona heat edition)

AdvancedMeshtasticMeshCoreAbout 2–4 hours

You'll need

A low-power nRF52 board (RAK4631
Heltec T114 or XIAO nRF52840 kit)
A battery suited to your board
A small 5–6 V solar panel matched to the board's solar input
A weatherproof enclosure with cable glands
An outdoor 915 MHz antenna

A solar node can run for years with no visits, if it’s low-power, sized for cloudy days and protected from heat.

1. Choose a low-power board

Use an nRF52 board. For example, Heltec’s T114 draws about 9 mA with GPS and screen off and has a built-in solar input rated for 5–6.5 V. ESP32 boards draw far more and need much bigger panels and batteries.

Board	Solar input	Note
Heltec T114	2-pin, 5–6.5 V (about 5 V panel recommended)	Very low power
Heltec V4 (ESP32)	2-pin, 4.7–6 V	Higher power draw
RAK WisBlock (RAK19007 base)	Solar connector into a linear Li-ion charger (no MPPT)	Modular, popular for solar

Always check your board’s own documentation for the exact panel voltage it accepts.

2. Size it for cloudy days

Measure or estimate your node’s average current draw.
Multiply by 24 hours for daily use (for example, 10 mA × 24 h = 240 mAh per day).
Size the battery for at least several days with no sun. Monsoon storms can bring stretches of cloud.
Size the panel to refill a day’s use in a few hours of good sun, with plenty of margin.

3. Beat the heat

Use a white or light-colored enclosure, and shade the box (the solar panel itself can shade it if mounted above).
Vent the enclosure with breathable vents or a downward-facing opening protected from rain.
Keep the battery in the shadiest, coolest spot in the box, away from the panel.
Check your battery maker’s charging temperature limits and avoid batteries without protection circuits.

4. Weatherproof it

Use cable glands for every cable and add a drip loop so water runs off before the entry.
Mount the box with openings facing down.
Use an outdoor-rated antenna; keep the coax short.
Ground the mast for lightning protection. See Mount a repeater safely.

5. Configure for low power

Meshtastic: use the right role (ROUTER or ROUTER_LATE only if your group agrees; otherwise CLIENT) and review the power settings.
MeshCore: flash repeater firmware and keep the advert interval at the default.
Turn off anything you don’t need: screen, GPS, Bluetooth if you manage it over the air.

6. Test on the ground first

Run it in your yard for a week, including through a cloudy day, before it goes up a pole.

Sources

Checked on October 18, 2026.