BQ25700A: Ni-MH 12S1P charger IC needed

Colin Brenton

Part Number: BQ25700A
Other Parts Discussed in Thread: BQ25720

Hi,

I'm trying to identify a chip which can charge and manage a 12S1P battery of Ni-MH cells. Someone else has asked this (see link below) but I think the replies are wrong, as the two parts they mention describe being able to handle 3 cells in series, not 12. Am I reading this right?

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/621195/bq25700a-part-selection-and-recommendation

So, does anyone know what chips are available to do a 12S1P pack? The search feature on the web shows nothing.

Ideally we'd like to implement input power via USB PD (although this may need an additional IC), and we also need power pass through, to both run the load and charge the battery from the incoming supply.

TIA for any leads.

Colin

over 1 year ago

0 Tiger Zhou over 1 year ago

TI__Mastermind 21885 points

Hi Colin,

When you mention 12S1P NiMH battery, each cell is 1.2V, so the max charge voltage is 14.4V. This is within the charge voltage range of BQ25700A (1~19.2V).

If additional feature is needed, you can take a look at BQ25720.

www.ti.com/.../BQ25720

Regards,

Tiger

0 Colin Brenton over 1 year ago in reply to Tiger Zhou

Prodigy 60 points

Hi,

Thanks, interesting answer. Why then does the device data sheet say on the first line "Charge 1- to 4-Cell Battery From Wide Range of Input Sources"?

Both things can't be true..

Cheers,

Colin

0 Tiger Zhou over 1 year ago in reply to Colin Brenton

TI__Mastermind 21885 points

Hi Colin,

BQ257xx was designed for Lithium Ion batteries. Each cell is 4.2V, it supports 1S-4S Li-On batteries.

Hope this clarifies.

Regards,

Tiger

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BQ25700A: Ni-MH 12S1P charger IC needed