I doubt you will be able to go lower than 60 seconds. To check you settings, try the following i2cget commands:
First check whether your ups pico is accessible using i2c:
sudo i2cdetect -y 1
this should show the ups pico's active i2c ports (default 68, 69, 6a and 6b)
Next, for verification, get the firmware version that is currently installed:
sudo i2cget -y 1 0x6b 0x00 b
on my systems it returns 0x5c
Next, get the 'battery run time':
sudo i2cget -y 1 0x6b 0x01 b
On my system it returns 0x00, which is the default and minimum time, 60 seconds.
Assuming the documentation is correct, the value in this register is multiplied by 60 and then added to the base value of 60 seconds. A value of 0xff turns off the timer.
These commands are valid for the Ups-Pico hardware version HV3.0 only.
For the older hardware version HV1.0 other registers were used, but since your link points to a HV3.0 module, I assume these are the ones you would need.