Other Parts Discussed in Thread: BQ24617
Hi,
I purchased your BQ24617EVM to help me with the design of a battery charging circuit for the RRC 2057 battery.
I am using a 12V power supply and I altered the charge voltage to 8.66V, charge current to 4A, and the termination current to 150mA.
The battery charges as expected and I have graphed the charge curve and I'm happy with how the chip operates. However, when I leave the chip to charge the battery the charge indicator LEDs (STAT1 and STAT2) do not behave as expected.
The STAT1 LED is ON and the STAT2 LED is OFF when the battery begins to charge (as is expected), but when I come back after the charging is complete the STAT1 LED is blinking and the STAT2 LED is OFF.
The scenario above has happened multiple times and so I watched it more closely and this is what I believe is happening. When the charging current drops below the chosen 150mA termination current, the BQ24617 chip ends charging as expected. The charger is now OFF and so VBAT is now the true battery voltage, which happen to fall from 8.66V to 8.06V when no current is sinked/sourced from the battery. The lower battery voltage measured from Vfb causes the charger to go into the Recharge state and the chip tries to charge the battery more, but it has already met the charge complete requirements so it stops charging.
The BQ24617 chip then gets stuck in this recharge / done charging loop which causes the STAT1 LED to flash.
Does anyone know away around this recharge state?
Any help will be appreciated,
