BQ24650: Disable precharge timeout

ChangedDaily

Part Number: BQ24650

Hi,

I would like to disable pre-charge timeout, i.e. if battery voltage has not risen above VLOWV threshold after 30 minutes I would like to continue to pre-charge, indefinitely. Is this possible, if so then how can I do this?

Thanks

over 6 years ago

0 Kedar Manishankar over 6 years ago

TI__Mastermind 24075 points

Hi Patrick,
30 minute in-built pre charge timer cannot be disabled for BQ24650. If 30 min timer has been reached, you can initiate a new cycle by toggling the CE pin, but you will need some form of external logic/MCU for that. Or precharge current can be increased, but it means fast charge current will increase, and termination current threshold will also be higher.

0 ChangedDaily over 6 years ago in reply to Kedar Manishankar

Prodigy 70 points

OK, thanks. Just to confirm by toggling CE you are referring to shorting of the MPPSET pin to ground and then releasing.

0 Kedar Manishankar over 6 years ago in reply to ChangedDaily

TI__Mastermind 24075 points

Hi Patrick,
Yes, for this part there is actually no CE so you can toggle the MPPSET under 75mV (to GND) and then release (above 175mV). This will reset the timer.

0 Shang Wu18 over 6 years ago in reply to Kedar Manishankar

Intellectual 270 points

Adding to this topic.

The (both) status pins activate when it reaches 30 minutes. Can we (N)AND these pins and connect to CE/MPPSET to essentially disable the 30-minute timer?

Or these pins will cause permanent logic LOW and disable the entire chip?

0 Kedar Manishankar over 6 years ago in reply to Shang Wu18

TI__Mastermind 24075 points

Hi Shang,
This would theoretically cause MPPSET/CE to toggle but is not recommended as STAT pins report other faults as well (refer section 8.3.20 of d.s), and you would constantly be trying to reset a charge cycle when one of the other fault conditions persists. For other questions, please feel free to open a new thread so information is easily accessible for the rest of the E2E community.

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BQ24650: Disable precharge timeout