Hi,
The system uses an Arduino Nano powered by a rechargeable 9v battery, which also powers the two servos and the bluetooth module
- How big is the 9V battery?
- What voltage are the servos rated at?
- Where do they get their power from?
- What rating are the servos, link to specs/data?
- What do the servos operate?
Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?
You project is showing classic symptoms of not enough current for all your devices.
Servos alone pull more than 1A each,.
Servos if needed to hold their position against a spring loaded or returning force will continue to draw considerable current.
Have you measured your battery volts while the fault occurs?
Thanks.. Tom.. 