The Model BVST105 is an intelligent Battery Voltage Sensor (BVS) designed to automatically operate the auto start enabled generator (2 wire start) and to control the battery bank voltage by automatically starting, running and shutting down the engine ones the run time set by multi-range timer elapsed.
How it works
Upon sensing the low voltage threshold (11.8Vdc) the BVS will wait for 5 sec to ensure the voltage recovers back to normal and stabilise above the high voltage threshold (12.8Vdc).If that happens the BVS will do nothing and remain in stand-by mode. However, if voltage hits the low voltage threshold and then stays below the high voltage threshold for more than 5 sec the BVS will trigger the multi-range timer simultaneously closing the auto start volt-free relay which would remain closed for the period set by multi-range timer (if the timer was initially enabled via DIP switch 2).
Functional Diagram (example)