ZeroTrace AirLeak Pro
Power & Battery
The 18650 cell, charging, the built-in protection, and runtime
AirLeak Pro runs from a single rechargeable 18650 cell with a built-in charger and full battery protection, and charges over USB-C.
Which battery
The board is built around one 18650 lithium-ion cell in the on-board holder.
Allowed
| Requirement | Detail |
|---|---|
| Chemistry | Lithium-ion (Li-ion), 3.7 V nominal (charges to 4.2 V) |
| Form factor | 18650 only, 18 mm × 65 mm cylindrical |
| Count | One cell |
| Top type | Flat-top or button-top |
| Protection | Unprotected (raw) cells are recommended, the board already protects the cell |
Not allowed
| Don't use | Why |
|---|---|
| Non-rechargeable / primary cells | Charging them is dangerous |
| LiFePO₄ (3.2 V) 18650 cells | Wrong voltage profile for a 4.2 V charger |
| Any other size (21700, 14500, AA/AAA, 9 V) | Won't fit and/or wrong voltage |
| Multiple cells | The board is single-cell only |
| Damaged, swollen, dented, leaking cells | Fire/explosion risk |
A "protected" 18650 has a small PCB at one end that makes it longer (typically 67–70 mm) and it may not seat in the holder. Because AirLeak Pro protects the cell electronically, you don't need a protected cell, a quality unprotected flat-top is the easiest fit.
Use a reputable brand (Samsung, LG, Sony/Murata, Molicel, Panasonic). Higher capacity (mAh) means longer runtime. Ignore no-name "9900 mAh" cells, they're overstated.
Built-in battery protection
The board includes a proper battery-management system, always active, even with USB unplugged, that guards the cell against all four classic failure modes:
| Protection | Prevents |
|---|---|
| Over-charge | The cell being pushed past its safe full voltage |
| Over-discharge | The cell being drained too flat (recovers when recharged) |
| Over-current | Too much current being pulled at once |
| Short-circuit | A dead short across the cell |
In plain terms: through normal use you can't easily over-charge, over-drain, or short this battery, the protection steps in and cuts the cell off, then restores it automatically once conditions are safe.
Charging
| Topic | Detail |
|---|---|
| Port | USB-C, 5 V, a normal phone charger, power bank, or PC port |
| Best charger | A 5 V / 2 A source charges fastest and is the most stable for running the board while plugged in |
| Indicators | Red = charging, Green = full / standby (driven by the charger, always accurate) |
| While off | The cell charges from USB-C regardless of the power switch |
| Fuel gauge | The board measures cell voltage and reports remaining charge to the app |
The board makes a steady 3.3 V internally whether the cell is near-full or nearly empty, so scanning performance doesn't sag as the battery drains.
Runtime & power integrity
Runtime depends on your cell's capacity and how hard the radios are working, dual-band Wi-Fi plus Bluetooth is the heaviest load.
During an active dual-band scan the radios draw a sharp current spike. A weak or thin USB cable, or a low-current port, can sag and trip a reset. For reliable scanning, run from a charged 18650 or a solid 5 V / 2 A USB-C source with a good cable.
For long storage, remove the cell and keep it at a partial charge (~40–60 %) in a cool, dry place, see Safety & Care.