Part Number: BQ24650
hi there,
I have designed a circuit using the BQ24650, referencing two different application notes.
Preventing bq24650 Leakage Current When Using Shaded Solar Panels,
Using the bq24650 to Charge a LiFePO4 battery
My setup is as follows:
Preventing bq24650 Leakage Current When Using Shaded Solar Panels,
Using the bq24650 to Charge a LiFePO4 battery
My setup is as follows:
- Battery: LiFePO4 (12.8V)
- Solar Panel: Vmp 18.4V / Voc 21.8V
[Issue Description]
During charging, the STAT1 LED remains ON as expected. However, I am experiencing an issue with the Sleep Mode transition and the LED status when the panel voltage drops.
During charging, the STAT1 LED remains ON as expected. However, I am experiencing an issue with the Sleep Mode transition and the LED status when the panel voltage drops.
According to the datasheet, the device should enter Sleep Mode when the panel voltage falls below the battery voltage, and the STAT1 LED should turn OFF. In my test, the STAT1 LED stays ON even when the panel voltage is lower than the battery voltage; it only turns OFF once the panel voltage drops below approximately 4V.
- When the panel voltage is 0V, the board's current consumption is about 30µA.
- Even when the panel voltage is low (not charging), the consumption remains constant at 30µA.
- The STAT1 LED does not turn OFF immediately when the panel voltage becomes lower than the battery voltage (VCC < VSRN).
I would like to understand why the STAT1 LED remains active until the input voltage drops as low as 4V, instead of turning off upon entering Sleep Mode.
[Additional Question]
1. Based on my panel specifications (Vmp 18.4V, Voc 21.8V), what would be the recommended voltage setting for the MPPSET pin for optimal performance?
2. Could you also perform a general review of my circuit design to see if there are any other potential issues or improvements needed?
1. Based on my panel specifications (Vmp 18.4V, Voc 21.8V), what would be the recommended voltage setting for the MPPSET pin for optimal performance?
2. Could you also perform a general review of my circuit design to see if there are any other potential issues or improvements needed?
