BQ25751:LVBD

William Trevine

Part Number: BQ25751

Tool/software:

Does the BQ25751 disconnect the battery? Is there any way to disconnect it other than the FORCE_BATFET_OFF register? After disconnection my microcontroller will turn off, consequently stopping the I2C connection, after the watchdog time the BQ25751 will return to the default settings and connect the battery again!?

4 months ago

0 William Trevine 4 months ago

Prodigy 10 points

Complementing: I will work with two 12V batteries, totaling 24V. I want to disconnect the battery at 21V, saving the battery from a deep discharge. As BQ25751 does not seem to have LVBD, I would do it manually, however, I run into the dilemma described above.

0 Christian Moyer 4 months ago in reply to William Trevine

TI__Mastermind 31541 points

Hello William,

William Trevine said:
after the watchdog time the BQ25751 will return to the default settings and connect the battery again!?

Do you need the watchdog timer in your system? Are you able to disable it?

Best Regards,

Christian

0 William Trevine 4 months ago in reply to Christian Moyer

Prodigy 10 points

Hi Christian,
I have verified that FORCE_BATFET_OFF is not reset by the watchdog, that is good, I will be able to make it work this way.
However, I find it strange that the BQ25751 does not have an automatic LVBD configuration. I will have to read the battery voltage and ask it to turn off. Is that right?

0 Christian Moyer 4 months ago in reply to William Trevine

TI__Mastermind 31541 points

Hello William,

William Trevine said:
However, I find it strange that the BQ25751 does not have an automatic LVBD configuration. I will have to read the battery voltage and ask it to turn off. Is that right?

Unfortunately we do not have a configurable LVBD. You will need to read the voltage with a fuel guage or similar device and disconnect battery using FORCE_BATFET_OFF

Best Regards,

christian.

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BQ25751:LVBD