Help to select battery gauge for my application.

Nikos Antoniou

Other Parts Discussed in Thread: BQ27520-G4

Hi everyone,

I design a low power battery operated hardware and I need to include a battery gauge. For my design I had initialy selected the BQ27421 and my problem is that each time the system shuts down and due to the fact that this is a ROM based gauge, if the power is disconnected the gauge will lose it's Qmax and Ra table from learning and will have to relearn them. As I have a little experience with battery gauging I need your advice on this aspect.. Should I choose a different battery gauge or could I work with the existing one? For example what battery gauge technology the cell phones use and they have accurate SOC after power disconnection? I prefere to stick with the BQ27421 since I have already written the library. Any guidance?

Thanks in advance

Nick

over 4 years ago

0 Wyatt Keller over 4 years ago

TI__Guru** 105590 points

Hello Nick,

You can save the Ra table and Qmax intermittently when the battery is connected and use your MCU to store the data and re-write to the gauge RAM in case of a power loss. If you are going to have power losses often I would recommend switching to a flash based gauge.

Sincerely,

Wyatt Keller

0 Nikos Antoniou over 4 years ago in reply to Wyatt Keller

Intellectual 820 points

Hi Keller and thank you for your answer,

Yes, probabaly I will have often power loss. Could you suggest me a low power flash based gauge with I2C communication?

Nick

0 Wyatt Keller over 4 years ago in reply to Nikos Antoniou

TI__Guru** 105590 points

Hello Nick,

I could recommend the BQ27520-G4 for your system, there are other flash based gauges you can review if your system has different needs.

Sincerely,

Wyatt Keller

Power management

Power management forum

Help to select battery gauge for my application.