BQ34110: this fuel guage IC is ok to use in my EV battery pack

Hi Raja,

What battery chemistry is being used in your design? BQ34110 is part of our "higher cell count gauge" family, along with BQ34z100-G1. These gauges used a resistor divider configuration, so the gauge is essentially reading a 1S voltage. Please refer to section 2.3.4 - 2.3.6 of the technical reference manual for this part for considerations for higher voltage application, since you stated the voltage exceeds 65,535 mV. 

Thanks,

Rushi

Hi Raja,

BQ34z100-G1 may be better for your application if you are discharging more frequently. Yes it can measure charge/discharge current. 

Thanks,

Rushi

Hi Raja,

Yes that is something to consider. BQ34z100-G1 is based on Impedance Track algorithm. When you said discharged daily or in two days, I assumed your application would have significant rest periods. Rest periods are an important aspect of this algorithm. Please refer to section 3.8 of the technical reference manual (https://www.ti.com/lit/ug/sluubw5/sluubw5.pdf), this device supports high current and high capacity batteries above 32 A and 29 Ah. 

For this market, e-bike/e-scooter/etc, our monitors have been popular in this space. In fact we have reference designs for this application and well as an application note written by our systems engineering team. It is very useful please read: https://www.ti.com/lit/wp/slyy185/slyy185.pdf

Thanks,

Rushi

Hello Raja,

The bq34z100-g1 is a top of stack gauge so it can go up to 65V with voltage divider scaling but the scale factor would likely be too high for the gauge to operate correctly by itself. You might be able to scale it more, but you would need to do your own calculations with the host.

Take a look at this E2E: https://e2e.ti.com/support/power-management/f/196/t/621143

It may help with your application.

Sincerely,

Wyatt Keller

Hi Raja,

Yes both BQ34z100-G1 and BQ34110 can support scaling. These devices natively support up to 65V stack, but scaling can be done to handle higher stack voltages. The resolution of the gauging gets worse as the divider ratio gets larger, just something to keep in mind. The BQ34z100-G1 was a newer revision of an older device, so it's likely the scaling section didn't get copied into the TRM, but appreciate you pointing this out to us. And yes, both IC's have similar structure but different algorithm. 

Thanks,

Rushi

Raja,

Here are some training videos and articles I was able to find that may be able to help you:

• https://training.ti.com/quick-introduction-bq34z100-g1-0
• https://training.ti.com/how-optimize-impedance-track-gauge-performance
• https://www.ti.com/lit/an/slua760/slua760.pdf
• https://www.ti.com/lit/ug/sluubw5/sluubw5.pdf
• https://www.ti.com/lit/an/slua790/slua790.pdf

Thanks,

Rushi

OK

thanks