The TinyHawk II comes set up from the factory with automatic PID profile selection based on cell count. This means that when you fly with a 1S LiPo battery, the drone will automatically select the proper PID Profile 1. Then, when you fly with a 2S LiPo battery, the drone will automatically select the proper PID Profile 2. 

However, it is suggested that you check this manually for the first few flights to confirm and gain confidence in the auto cell count system. To do so, use the BetaFlight On Screen Display (OSD). To enter the Betaflight OSD menu, simply move your left stick (of your controller) throttle to the center and yaw left, while pitching forward with the right stick.

It is similar to entering the OSD menu for SmartAudio, video band/channel changing, as here: Except, instead of going into Features - VTX SA... Please go into Profile, where you can change Profile (PID profile) and Rate (rate profile).)

More importantly, has come to our attention that some pilots are not heeding the yellow/black warning card that comes with the TinyHawk II, which states that when switching between 1S and 2S LiPo operation, both the PID Profile and Rate Profile need to be changed via the OSD. Please note that while the PID Profile should automatically switch based on 1S or 2S LiPo usage, the Rate Profile does NOT change automatically. For proper flight characteristics and to keep your drone within warranty, it is vital that you change the Rate Profile to match 1S or 2S LiPo usage. Rate Profile 1 for 1S LiPo; and, Rate Profile 2 for 2S LiPo. This is because there are throttle curve/limit settings incorporated into the Rate Profile for each respective LiPo voltage, whether 1S or 2S LiPo usage.