BQ27426: Battery Pack SoC Calculation Method

Sahil Nayak

Intellectual 450 points

Part Number: BQ27426

Hi TI Team,

We are using BQ27426 Fuel gauge in our custom design.

We wanted to know more about SoC calculation. What parameters affect the SoC change?

If battery voltage drop suddenly when load is applied, will the SoC also drop?? Is SoC, voltage dependent?

Note: After disconnecting load, original voltage is restored.

Thanks & regards.

over 4 years ago

0 Sahil Nayak over 4 years ago

Intellectual 450 points

Hi,

Any update on this??

0 Dominik Hartl11 over 4 years ago in reply to Sahil Nayak

TI__Guru 64366 points

Please check out the gauging training videos on https://training.ti.com/gauges-track-battery-management-deep-dive-2020

For Impedance Tracking (bq27426), SOC is based on discharge simulations so there are many parameters that affect the result. Voltage is just one. In general, SOC will start to decrease *depending on the current* (not directly because of measured voltage). SOC will zero out, if the voltage drops below terminate voltage during a discharge, by definition.

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BQ27426: Battery Pack SoC Calculation Method