BQ24074: Preventing deep discharge of Li-ion battery

philip smith

Part Number: BQ24074
Other Parts Discussed in Thread: BQ24075, LMS33460

Do the TI Power management parts in the BQ2407x series have any provision for limiting the discharge of Li-ion batteries?

over 7 years ago

0 Raheem over 7 years ago

TI__Mastermind 21590 points

Hello Philip,
The BQ2407x devices don't have any protection for deep discharge of the battery. Some battery packs come with protection switches which turn off when the battery reaches a certain level.

0 philip smith over 7 years ago in reply to Raheem

Prodigy 70 points

Thanks, Raheem.
I have decided to use the BQ24075 with a NCP301HSN30T1G voltage supervisor connected to the battery and the SYSOFF terminal. I think this will prevent battery discharge below 3.0V to protect a Li-ion cell. Have you seen this done before?
Phil

0 Raheem over 7 years ago in reply to philip smith

TI__Mastermind 21590 points

Philip,
I've seen the use of supervisors before with battery chargers for multiple applications and i think this should work. Please look at the LMS33460 3V undervoltage detector.

0 philip smith over 7 years ago in reply to Raheem

Prodigy 70 points

Thanks,
The NCP301HSN30T1G has an open drain active high output which is a must for this function. I did not see any TI parts that would work.
Phil

0 philip smith over 7 years ago in reply to philip smith

Prodigy 70 points

I think this circuit solves the problem of over discharging Li-ion batteries. Any thoughts?

Phil

PWR MGMT .pdf

Pwr Mgmt.pdf

0 philip smith over 7 years ago in reply to Raheem

Prodigy 70 points

2388.PWR MGMT .pdfI think this circuit solves the problem of over discharging Li-ion batteries. Any thoughts?

0 philip smith over 7 years ago in reply to Raheem

Prodigy 70 points

Raheem

Sorry I posted the wrong file, this is the solution I would like to discuss:

1715.Pwr Mgmt.pdf

0 Raheem over 7 years ago in reply to philip smith

TI__Mastermind 21590 points

Philip,
I think that should work.

0 philip smith over 7 years ago in reply to Raheem

Prodigy 70 points

Thanks Raheem

The circuit uses a wired OR of the open drain outputs feeding the SYSOFF input, and there are some pretty critical part choices to meet all the voltage constraints. I appreciate your evaluating it.

Phil

Power management

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BQ24074: Preventing deep discharge of Li-ion battery