BQ28Z610: Question for 0V precharge

Wu JW

Part Number: BQ28Z610

Hi,

We found the BQ28Z610 can support the 0V precharge function in application note, but we can't find more detail info in the datasheet. Could you give more detail function for this function?

Can we disable the 0V precharge function? My customer want that the BQ28Z610 can't be charged when the cell voltage <1.5V, how can we set it? Thanks a lot!

over 6 years ago

0 Onyx Ahiakwo over 6 years ago

TI__Guru* 76230 points

The 0V charge function wouldn't work if you do not have charger connected at the pack+and pack- and it isn't something that can be disabled. The gauge would short the charge fet gate to pack + and thus turn on the charge fet to allow trickle charging the battery.
thanks
Onyx

0 Wu JW over 6 years ago in reply to Onyx Ahiakwo

TI__Intellectual 2935 points

Hi, Ahiakwo,

Can we use the external circuit to realize the function as stop 0V charger function when the cell voltage <1.5V? Do you have some reference circuit? Thanks a lot!

0 Onyx Ahiakwo over 6 years ago in reply to Wu JW

TI__Guru* 76230 points

Hi JW,
It is possible to think of a circuit that will prevent that, but i do not have any reference schematic to share.
thanks
Onyx

0 Wu JW over 6 years ago in reply to Onyx Ahiakwo

TI__Intellectual 2935 points

Do you some suggestion for that? How to realize it?

0 Wu JW over 6 years ago in reply to Onyx Ahiakwo

TI__Intellectual 2935 points

Hi, Onyx,

Can we use following circuit(Red square) to disconnect the PACK pin when the cell voltage below a low voltage? Thanks a lot.

0 Onyx Ahiakwo over 6 years ago in reply to Wu JW

TI__Guru* 76230 points

hi JW,
I am not sure how that will work because if the gauge is in shut down mode and needs to be woken up, pack pin needs to see a voltage to wake up. if we have 4 voltage on P+, the gate of V2 will see 2V. Would that not turn V2(pfet) on and allow the 0V charging of the battery through the pack Pin?

thanks
Onyx

0 Kaihua Guo over 6 years ago in reply to Onyx Ahiakwo

Prodigy 40 points

Hi,Onyx

Can we use following circuit(Red square) to inhibit charge when the cells voltage below a voltage like 3V? Thanks a lot.

0 Onyx Ahiakwo over 6 years ago in reply to Kaihua Guo

TI__Guru* 76230 points

Hi Kaihua,
This appears viable. pls thoroughly test functionality and that it doesn't affect gauging operation.
thanks
Onyx

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BQ28Z610: Question for 0V precharge