BQ25890: 路径管理在什么情况 会只选择 输入源 input source (VBUS), 而不消耗电池电能？

您好，

1) REG03[4] 'CHG_CONFIG' set to 0 will stop battery charging and result in VBUS power supply only on VSYS. Please be aware with charge disabled the battery is still allowed to discharge to SYS for the case where SYS load requires more current than VBUS input can supply. 

2)REG09[5] 'BATFET_DIS' set to 1 will also result in VBUS power supply only on VSYS. It is okay to set this bit to 1 with VBUS already plugged in; it will force BATFET turn off. With 'BATFET_DIS' set to 1 battery will not discharge to support SYS. The device will not be able to enter supplement mode. Additionally, please be aware that if 'BATFET_DIS' is set to 1 before VBUS is connected the input plug in event will exit ship mode and reset BATFET_DIS = 0. 

To summarize either option 1 or 2 is acceptable to set BQ25890 to only power VSYS. You will need to decide if you want to allow battery to discharge. If ability to discharge is desired then option 1) should be used.