Power

Power decides where a node can live. A node on a desk next to a USB charger needs no thought. A node on a roof, in a loft or on a hill needs a plan, and most failures come from the power supply rather than the radio.

USB

Most boards in the hardware buyer's guide are powered and flashed over USB-C. Some practical points from Meshtastic's documentation:

• Use a cable that carries data, not a charge-only cable, when you flash or configure the board. Meshtastic's getting-started guide tells you to confirm the cable carries data.
• ESP32 boards such as the Heltec V3 may need a serial driver (CP210x or CH340 are named). The Heltec V4 removed the CP2102 chip, so that driver advice applies to the V3 and older boards. nRF52 and RP2040 boards use a UF2 bootloader and need no serial driver.
• The Heltec V3 doesn't need an SD card: firmware and settings live in its onboard flash, and you flash it over USB (see Meshtastic's ESP32 flashing guide).
• Fit the antenna before you connect power. See antenna placement.

For a fixed node, a mains USB adapter is the simplest, most reliable power supply. A node left permanently on a phone charger is a perfectly good repeater if the position is good.

Power banks

Power banks are the usual way to run a node without a socket, but many are designed to charge phones. They detect low current as "device finished charging" and switch off. A LoRa node idling at a few milliamps looks exactly like that.

Zak Kemble measured three banks and found cut-off thresholds and delays as follows:

The practical consequence is editorial inference, not a measured claim about your bank: a low-draw node may be cut off by some banks. Options:

1. Buy a bank with a "low-current" or "always-on" mode, and test it by leaving the node running overnight.
2. Add a keep-alive module that pulses a load. Kemble describes this approach.
3. Add a resistor load. It works, but it wastes battery.

Do not leave a power bank in an unattended, sealed enclosure in direct sun or a hot loft. Lithium batteries dislike heat.

ESP32 and nRF52 power classes

Two chip families dominate LoRa mesh boards:

We do not publish idle or transmit current for either family. Earlier drafts relied on forum snippets that we could not open, and the source is no longer reachable, so those figures have been removed. Real draw depends on firmware settings, GPS, display and transmit activity, so measure your own node.

18650 and LiPo cells

Several boards take a lithium cell directly. Read the hazards before connecting one.

Specifics we can source:

• The LILYGO T-Beam Supreme has an 18650 holder. Meshtastic's documentation notes that it takes unprotected flat-top cells, and that button-top or protected cells longer than 65 mm do not fit. An unprotected cell has no built-in protection circuit, so you are relying on the board for charge control. Buy from reputable sellers and avoid mixing cells.
• The Heltec V3 uses an SH1.25-2 battery connector. The V4 keeps it and adds an SH1.25-2P solar port and an SH1.25-8P GNSS port.
• Do not charge lithium-ion or LiFePO4 below 0 °C. We saw this in a solar-node planning page (snippet only, not fetched, unconfirmed); it is also widely given as general lithium-cell guidance. This matters for any outdoor node in a British winter.

Solar, later

Solar is attractive for a hilltop repeater but is the hardest part to get right. Our solar sizing tool estimates a panel and 18650 battery from PVGIS December sunshine data for ten UK places, and lists every assumption it makes. We still have no verified power-draw figures for ESP32 or nRF52 boards, so its device-current presets are unsourced planning placeholders: measure your own node and enter the figure. What we can say:

• Meshtastic's RAK Wireless pages list solar products such as the WisMesh Repeater and Repeater Mini.
• The Heltec V4 has a dedicated solar port.
• A search snippet describes one integrated product, the ThinkNode M6, with a 6 W monocrystalline panel, MPPT charging and a 7000 mAh pack rated -20 to 60 °C. That is a vendor claim we did not confirm; it shows what an integrated unit looks like, not how to size your own.
• Short winter days and cloud cover in the UK mean an undersized panel will run flat. Choose a low-power board, a generously sized cell, and test before you climb a mast.

Choosing a setup

Related: antenna placement, flash Meshtastic, flash MeshCore, which mesh is right for you.