BQ25606: Maximizing battery system power by connecting to Vbat

D N

Part Number: BQ25606

Hi there,

I'm interested in trying to get every last drop of power out of my lithium battery, so a few questions

- can I connect my system (small arduino style microcontroller) directly to Vbat to avoid the voltage drop of BATFET? If I keep the system in reset while charging maybe?

- if using an unprotected cell is it recommended to have an additional cell prottection IC (such as BQ297xx) or is the BQ25606 sufficient?

Thank you

over 5 years ago

0 Ning T over 5 years ago

TI__Guru 57611 points

Hi,

1. Yes, but the system may not start up when the battery is depleted.

2. The charger has just basic battery protection functions. Separate battery protection circuitry is recommended for full battery protection.

Thanks,

Ning

0 D N over 5 years ago in reply to Ning T

Prodigy 30 points

Thanks Ning,

Can you explain point #1 a bit more? Why would it not start up when the battery is depleted and what could I do to make sure it does?

Thanks

0 Ning T over 5 years ago in reply to D N

TI__Guru 57611 points

Hi,

Assuming the system requires 3.5V to work, if the battery is only 2.5V, the battery will not be able to support the system if connecting the system to the battery directly.

BQ25606 supports Narrow VDC (NVDC) power path management – Instant-on works with no battery or deeply discharged battery.

Please visit the videos below for charger operations and valuable tips.

Battery chargers and features

3.1 Introduction to Li-Ion battery charging

3.2 Battery charger system overview

3.6 Fast-Charging Trends and Challenges for Single-cell Batteries

Thanks,

Ning.

Power management

Power management forum

BQ25606: Maximizing battery system power by connecting to Vbat