Snowbird Lite 1S
The entry price, for cells that bring their own protection.
For protected LiPo pouches: the same charger, rails, inputs, supervisor and library, with a voltage-only gauge in place of the BMS and no radio. Everything you learned on the Feather 1S applies.
- Same pinout, same library, same safety ceilings
- No radio: for sites and customers that forbid one
- 24 µA idle, the lowest in the line
- Requires a cell with its own protection board
$34.00 CAD
Bare board, no cell. Pinout card and compliance insert included.
Shipping from $9.95 CAD in Canada, tracked. US orders ship duty prepaid. Also on Tindie. Ten or more? Ask about wholesale.
Specifications
Lite 1S, in numbers
Values marked measured come from the characterization report of 14 September 2026.
Battery
| Cells | 1S, protected pouch cell required |
|---|---|
| Chemistries | Li-ion, LiPo, LiHV, LiFePO4 |
| Battery connector | 3-pin JST-PH (BAT, NTC, GND) |
| Protection | None on board; the cell's own protection board is required. Temperature gating and charge ceilings still apply |
| Fuel gauge | Voltage-based state of charge, voltage, temperature 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 |
Outputs
| 3.3 V rail | 1.5 A continuous 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 | STM32U0, Zephyr firmware, I2C at 0x36 |
|---|---|
| Bluetooth LE | None |
| Idle current | 24 µA outputs unloaded; 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 |
Feather header
| Position | Signal | Direction | Note |
|---|---|---|---|
| 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 rest of the line
Same pinout, different battery.
Snowbird Feather 1S
$59.00 CADThe default. A complete 1S power system on a Feather.
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Snowbird Core 1S
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Snowbird 18650
$64.00 CADRaw cylindrical cells, the cheapest capacity there is, made safe.
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Snowbird Pack
$89.00 CAD2S to 4S packs with balancing, for robots and anything above 5 V.
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