is another under-voltage protection example.
As usual, discharging is cut off at 3.0V. By now, the
state detection signal vst is kept at low. About 18
seconds thereafter, charger is connected to the battery
string, and causing vst turning high. Therefore, the
controller permits the charging request and reconnects
the relay. Meanwhile, vst falls down due to the short
circuit on terminals C and D in Fig. 6.