Research Note: A Local AI Has to Survive the Watt-Hour Ledger
Published May 2026
Question
The simplest off-grid calculation is also the one most likely to be skipped: watt-hours divided by sustained watts. Pockot starts with that ledger because a useful local model is not useful if it runs only as a wall-powered demo.
Source-Backed Data Points
- The FAA states that spare lithium-ion batteries and power banks are limited to 100 watt-hours per battery for ordinary passenger-aircraft carriage. Source: FAA PackSafe.
- Apple states that M4's Neural Engine reaches up to 38 trillion operations per second. Source: Apple M4.
- Raspberry Pi lists AI HAT+ accelerator variants at 13 TOPS and 26 TOPS. Source: Raspberry Pi AI HAT+ documentation.
Reading
The 100 Wh reference is practical because it is a familiar portable boundary. It does not say what a product should be. It gives the calculator a conservative battery field. At 10 sustained system watts, 100 Wh is 10 hours before overhead. With a 1.2 overhead multiplier, the same envelope becomes about 8.3 modeled hours.
The word "sustained" matters. Peak NPU numbers do not include the whole system. The device also pays for CPU, memory, storage, display, sensors, voltage conversion, idle losses, and thermal behavior. Pockot should record measured wall or battery draw whenever possible.
Tool Rule
The calculator will show runtime as a model output and daily energy as a second output. If a device needs 12 sustained watts with overhead, one full day is not a 100 Wh problem; it is a roughly 346 Wh problem in the current model.