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Snowbird Power Systems
The Snowbird Feather 1S: a matte navy Feather-sized circuit board with gold castellated edges, a USB-C port, white JST connectors, a shielded Bluetooth module with a chip antenna, a power inductor and the Snowbird wordmark in white silkscreen.

Snowbird Feather 1S

The default. A complete 1S power system on a Feather.

Charger, BMS, fuel gauge, 3.3 V and 5 V rails, USB-C and solar inputs, and a Bluetooth LE supervisor on a castellated Feather. Stack it under any Feather host, drop it on a breadboard, or solder it down.

  • Raw LiPo or Li-ion pouch cells, protected on the board
  • USB-C and solar in one part, 10 W continuous
  • BTHome to Home Assistant with no integration work
  • One register map across Arduino, C and MicroPython

$59.00 CAD

Bare board, no cell. Pinout card and compliance insert included.

In stock

Shipping from $9.95 CAD in Canada, tracked. US orders ship duty prepaid. Also on Tindie. Ten or more? Ask about wholesale.

Specifications

Feather 1S, in numbers

Datasheet view

Values marked measured come from the characterization report of 14 September 2026.

Battery

Cells 1S
Chemistries Li-ion, LiPo, LiHV, LiFePO4, LiSOCl2 primary mode
Battery connector 3-pin JST-PH (BAT, NTC, GND)
Protection Overcharge, overdischarge, overcurrent, short circuit, temperature; programmable per chemistry
Fuel gauge State of charge, voltage, current, temperature, time to empty; ±3 % on LiFePO4 after one cycle measured

Inputs

USB-C 5 V at 0.5, 1.5 or 3 A, read from the CC lines
Solar 6 to 22 V, MPPT, 10 W continuous, 15 W peak measured
Charge current 50 mA to 3 A in 10 mA steps; default 0.5 C
Charger efficiency 94 % peak, 91 % at 3 A measured
Power path Load runs from the input while the battery charges; ideal-diode handoff when the input is lost

Outputs

3.3 V rail 1.5 A continuous, always on inside the discharge window measured
5 V rail 2 A continuous, switchable; off by default measured
Signals PG, CHG_DONE, INT, EN5V on jumpered Feather positions; VSYS and VBAT on pads

Supervisor

Supervisor nRF52840 module, Zephyr firmware, I2C at 0x36
Bluetooth LE BTHome v2 broadcast, Battery Service, custom GATT; read-only by default
Idle current 28 µA outputs unloaded; 42 µA advertising every 2 s; 3 µA in ship mode measured
Libraries Arduino, C, MicroPython; one register map, v1.2

Physical

Outline Feather, 50.8 × 22.86 mm, castellated, four mounting holes
Board 4-layer, ENIG, matte navy
Operating temperature −40 to 85 °C board; charge and discharge windows set per chemistry

Feather header

PositionSignalDirectionNote
3V 3V3 out Regulated 3.3 V; drives the host's 3V position
EN EN (host) out Pulled low through a jumper closed by default, so the host's own regulator stays off
BAT — — Not connected, by design: the host's charger must never see the battery
USB — — Not connected, so two 5 V sources are never in parallel
11 INT out, open drain Event interrupt; jumper open by default
A2 PG out, open drain Power good, both rails in regulation; jumper open by default
A3 CHG_DONE out, open drain Charge complete; jumper open by default
A5 EN5V in, pulled up Enable the 5 V rail; jumper open by default
SDA, SCL I2C — Qwiic bus at 3.3 V; the supervisor answers at 0x36
GND GND —
off header 5V 2-position 3.5 mm screw terminal block and a pad Rated 2 A; switched by EN5V and set5V()
off header VSYS Pad and castellation Raw system rail, battery or input, whichever the power path selects
off header VBAT Pad and castellation Battery terminal after the BMS switch; never the host's BAT position
off header NTC Battery connector pin 2 and a pad 10 kΩ, B = 3435 by default; other B values are a setting

The full map, with the host positions each jumper uses and why, is on the pinout page.

The Snowbird Feather 1S from directly above, showing the USB-C port, Qwiic and solar connectors at one end, the Bluetooth module at the other, and the battery connector, terminal block, charger and LEDs between them.

The rest of the line

Same pinout, different battery.

The Snowbird Core 1S: the Feather 1S board with the USB-C, Qwiic and solar connectors left off, their gold pads exposed, ready to solder onto a carrier.
1S · module BLE

Snowbird Core 1S

$49.00 CAD

The Feather 1S as a solder-down module for your own PCB.

Specifications
The Snowbird 18650: a longer Feather-width navy board with an on-board 18650 cell holder holding one unbranded cell, USB-C and connectors at one end and the Bluetooth module at the other.
1S · 18650 BLE

Snowbird 18650

$64.00 CAD

Raw cylindrical cells, the cheapest capacity there is, made safe.

Specifications
The Snowbird Pack: a double-width navy Feather board with a yellow XT30 connector and a white balance connector along its wide side, with a small shrink-wrapped three-cell pack plugged in behind it.
2S to 4S BLE

Snowbird Pack

$89.00 CAD

2S to 4S packs with balancing, for robots and anything above 5 V.

Specifications
The Snowbird Lite 1S: a Feather-sized navy board like the Feather 1S but with a small bare microcontroller in place of the Bluetooth module.
1S · no BMS

Snowbird Lite 1S

$34.00 CAD

The entry price, for cells that bring their own protection.

Specifications