[Solved] witty pi 4 cuts power not shutting down gracefully
I recently installed a witty pi 4 on my Raspberry PI 4. I'am running 13volts power (car battery simulation) into the XH2.54 connector. I want the raspberry pi to start up when there is power and to shutdown gracefully when power is cut.
The default setting of the witty pi are changed at the following properties:
- low voltage threshold is set to 2.0 volts
- recovery voltage is set tot 2.5 volts
- Default state when powered: ON
When i put the 13 volts on the connector the raspbery pi start up. But when i cut the 13volts power (to 0) it instantly cuts the raspberry pi. There is no gracefull shutdown of the raspberry pi when the voltage treshold is below 2.0 volts. What am i doing wrong?
Raspberry Pi needs to be powered to finish the graceful shutdown. If you disconnect the power supply completely, there is no way Raspberry Pi can continue working and perform the shutdown.
The low-voltage threshold should not be used like that. It should be configured to a voltage that the battery is about to run out, so Witty Pi can shutdown Raspberry Pi before the battery gets fully discharged. This will avoid damaging the Raspberry Pi and also prolong the lifetime of battery.
For 12V car battery (about 13V after fully charged), the low-voltage threshold should be set to 10.5V or higher, otherwise the battery will be over discharged.
Witty Pi has only one power input channel, and should not be used as UPS. Zero2Go Omini has 3 power input channels, and can be used as UPS (one channel for main power supply and one channel for backup power supply).