The same board as the Feather 1S with the USB-C, solar and Qwiic connectors left off and their signals brought to the castellations. For product teams who want the charger, BMS, gauge and supervisor as one tested part on their own carrier.
Highlights
- Every signal on castellations, including USB data and solar input
- Same firmware, same register map, same library as the Feather 1S
- Pre-certified radio module; carry "Contains" labels, not a radio test
- Reel-friendly packaging on request for runs of 100 or more
Battery
| Cells | 1S |
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| Chemistries | Li-ion, LiPo, LiHV, LiFePO4, LiSOCl2 primary mode |
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| Battery connector | 3-pin JST-PH (BAT, NTC, GND), or the VBAT, NTC and GND castellations |
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| Protection | Overcharge, overdischarge, overcurrent, short circuit, temperature; programmable per chemistry |
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| Fuel gauge | State of charge, voltage, current, temperature, time to empty; ±3 % on LiFePO4 after one cycle (measured) |
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Inputs
| USB input | VBUS, CC1, CC2, D+ and D− on castellations; 5 V at up to 3 A |
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| Solar | 6 to 22 V on castellations, MPPT, 10 W continuous, 15 W peak (measured) |
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| Charge current | 50 mA to 3 A in 10 mA steps; default 0.5 C |
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| Charger efficiency | 94 % peak, 91 % at 3 A (measured) |
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Outputs
| 3.3 V rail | 1.5 A continuous (measured) |
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| 5 V rail | 2 A continuous, switchable; off by default (measured) |
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| Signals | PG, CHG_DONE, INT, EN5V, SDA, SCL, VSYS, VBAT on castellations |
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Supervisor
| Supervisor | nRF52840 module, Zephyr firmware, I2C at 0x36 |
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| Bluetooth LE | BTHome v2 broadcast, Battery Service, custom GATT; no-radio firmware build available |
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| Idle current | 28 µA outputs unloaded; 42 µA advertising every 2 s; 3 µA in ship mode (measured) |
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| Libraries | Arduino, C, MicroPython; one register map, v1.2 |
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Physical
| Outline | Feather, 50.8 × 22.86 mm, castellated, four mounting holes; 3.1 mm tall with no connectors |
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| Board | 4-layer, ENIG, matte navy |
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| Operating temperature | −40 to 85 °C board |
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Feather header
| 3V | 3V3 · out · Regulated 3.3 V; drives the host's 3V position |
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| EN | EN (host) · out · Pulled low through a jumper closed by default, so the host's own regulator stays off |
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| BAT | — · — · Not connected, by design: the host's charger must never see the battery |
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| USB | — · — · Not connected, so two 5 V sources are never in parallel |
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| 11 | INT · out, open drain · Event interrupt; jumper open by default |
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| A2 | PG · out, open drain · Power good, both rails in regulation; jumper open by default |
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| A3 | CHG_DONE · out, open drain · Charge complete; jumper open by default |
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| A5 | EN5V · in, pulled up · Enable the 5 V rail; jumper open by default |
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| SDA, SCL | I2C · — · Qwiic bus at 3.3 V; the supervisor answers at 0x36 |
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| GND | GND · — · |
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| 5V | 2-position 3.5 mm screw terminal block and a pad · Rated 2 A; switched by EN5V and set5V() |
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| VSYS | Pad and castellation · Raw system rail, battery or input, whichever the power path selects |
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| VBAT | Pad and castellation · Battery terminal after the BMS switch; never the host's BAT position |
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| NTC | Battery connector pin 2 and a pad · 10 kΩ, B = 3435 by default; other B values are a setting |
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Physical
| Mass | 7.1 g |
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| HS code | 8504.40.95 |
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| Origin | Assembled in China; designed and tested in Canada |
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Compliance
- CAN ICES-003(B) / NMB-003(B)
- This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.
- Contains IC: 8017A-MDBT50Q
- Contains FCC ID: SH6MDBT50Q
- The radio module is exempt from RF exposure evaluation (RSS-102 Issue 6, FCC 47 CFR 2.1091) at any separation distance; keep the antenna area clear of metal.
- RoHS 2011/65/EU and (EU) 2015/863 compliant.
- REACH: contains no SVHC above 0.1 % w/w.
- Country of origin: Assembled in China; designed and tested in Canada.
- Export classification: EAR99. HS 8504.40.95.
No cell is supplied with this board. Set the chemistry jumper for the connected cell before the first charge. Safety: https://www.snowbirdpower.com/docs/safety. Security disclosures: [email protected]. Generated from the product data record on 2026-10-21.
