What drives the number
- Backlight: the difference between weeks and days; brightness level scales it almost linearly
- Connection mode: 2.4 GHz draws somewhat more than Bluetooth for its lower latency; both are efficient
- Sleep behavior: the board's idle sleep is what makes multi-week figures real; disabling sleep for instant wake trades battery for convenience
Practical expectations
A typical office pattern (eight hours a day, lighting off, Bluetooth) lands comfortably in the multi-week range per charge; the same pattern with medium RGB lands around a week. NuPhy's quoted maximums assume lighting off and modest use, as every vendor's do.
Charging notes
The board charges over USB-C and works wired while charging, so a dead battery is an inconvenience, not downtime. For travel, lighting-off is the habit that makes the charger stay home.
Runtime killers owners discover late
Battery complaints in the community usually trace to settings, not the cell. Disabling sleep for instant wake keeps the board partly awake around the clock, and the cost compounds quietly. Bright or white-heavy lighting effects draw more than dim single colors, since white fires every subpixel in each LED. And a board tossed into a bag while still in wireless mode can wake repeatedly from pressed keys in transit, arriving flatter than it left.
If runtime falls off a cliff without a settings change, rule those three out before suspecting the battery itself; genuine cell degradation is gradual and takes years of charge cycles to become obvious.
Long-term battery health
The Air75 V2 runs on a lithium pack, so the universal lithium rules apply. Heat is the main ager: avoid hot cars and sun-baked windowsill desks. Sitting for months at full charge is the second stressor; if the board will be stored a while, the community habit of leaving lithium devices around half charge is the gentle option.
Day to day, there is no need to babysit it. Topping up whenever convenient is fine, and the widely cited 20 to 80 percent guidance is about squeezing out extra years, not a requirement. Expect capacity to shrink slowly over years of use regardless; that is chemistry, not a defect.