You're right to look for a proper explanation — power management with variable voltage adapters can be confusing, especially with USB-PD or smart chargers like Lenovo's.
Your colleagues are correct in theory: the Lenovo adapter can only output 5V at 2A, which means 10W max at 5V. That’s well below the combined 30W your Pi and servo HAT need. So technically, your setup should be underpowered.
Why it worked anyway:
Most likely, your Pi and servo HAT are not pulling full 3A each in practice. Idle Pi usage is closer to 0.6–1.5A, depending on peripherals, and unless both servos and the fan are running at full load constantly, the HAT probably draws less than peak. You're operating below the rated limit most of the time, which makes the setup appear stable, but it's risky.
Your colleagues are correct in theory: the Lenovo adapter can only output 5V at 2A, which means 10W max at 5V. That’s well below the combined 30W your Pi and servo HAT need. So technically, your setup should be underpowered.
Why it worked anyway:
Most likely, your Pi and servo HAT are not pulling full 3A each in practice. Idle Pi usage is closer to 0.6–1.5A, depending on peripherals, and unless both servos and the fan are running at full load constantly, the HAT probably draws less than peak. You're operating below the rated limit most of the time, which makes the setup appear stable, but it's risky.
Statistics: Posted by fatirsahi — Sat Jun 21, 2025 6:23 pm