Other Parts Discussed in Thread: INA226
I'm using solar charger BQ24650 to charge LiFePO4 9Ahr, 12V battery at 14.2V, 2A max.
Since we connect to load directly to the battery terminal after the sense resistor, the system load when it's not charging is around 250mA in idle state.
This is higher than precharge 0.2A so when the battery is depleted to ~10.478V, with 575K/100K divider at VFB < VLOW of 1.55V, the pre-charge timer seems to expire after 30 minutes and the IC seems to go to FAULT condition.
We would have to remove the solar input and reconnect to reset.
Is there a way to disable the pre-charge so that even at 10.478V, it can fast charge the battery to supply enough current to the load?
Perhaps we could also toggle /CE (mppset) to reset the cycle once a day to avoid potential timer issue.
I can't find what the fast charge timer value is. If the load is drawing 250mA through the battery or through sense resistor, the fast charge might take longer time to complete since it detects Vbat=14.2 but I charge is still greater than 200mA.
-Khoi