Recommendation for a Fuel Gauge

Elizabeth Russell

Other Parts Discussed in Thread: BQ27500, BQ27505-J5, BQ27441-G1, BQ27510

I would like a recommendation for a fuel gauge for an application that uses a 18350 rechargeable Li-Ion battery that is not embedded but removed from the unit for charging. Basically all that is needed is SOC and the accuracy can be around 5%.

over 4 years ago

0 Batt over 4 years ago

TI__Mastermind 42535 points

Hi Elizabeth,

Please confirm if it's 1s or multi cell.

0 Elizabeth Russell over 4 years ago in reply to Batt

Prodigy 220 points

It is just one cell.

Elizabeth

0 Elizabeth Russell over 4 years ago in reply to Elizabeth Russell

Prodigy 220 points

What I would like to know is whether any of the fuel gauge devices (with any of the different algorithms) can accurately determine SOC when the charging cycle is not done in the presence of the fuel gauge. And is there a best algorithm choice for this case where charging is done externally?

0 Onyx Ahiakwo over 4 years ago in reply to Elizabeth Russell

TI__Guru* 76230 points

Hi Elizabeth

I would recommend the bq27520 given you need a system side gauge.

thanks

Onyx

0 Elizabeth Russell over 4 years ago in reply to Onyx Ahiakwo

Prodigy 220 points

Thank you for your response. Could you elaborate on why you recommended the bq27520? I have been using the bq27500, bq27505-J5, and more recently the 27510-G3 when it looked like the bq27505-J5 was NRND (but I see that has changed). These applications used an embedded Li-Ion battery and the results have been very good. I wasn’t sure whether the Impedance Track algorithm was the best choice for a removable battery situation and one where the needed accuracy wasn’t as great. I am looking at the bq27441-G1 as a possibility for an Impedance Track device - which seems to require a little less setup. Any thoughts?

Thanks,

Elizabeth

0 Onyx Ahiakwo over 4 years ago in reply to Elizabeth Russell

TI__Guru* 76230 points

The bq27441 is a rom gauge and you do not have the flexibility of programming a chem id.

The other gauges you mentioned which you use are all IT gauges. If they work well in your past removable applications, you can continue using them. The bq27510 and bq27520 are just improved versions of the 500 and 505. The IT algorithm is improved.

thanks

Onyx

0 Elizabeth Russell over 4 years ago in reply to Onyx Ahiakwo

Prodigy 220 points

Thank you for the response.

I have not had any removable applications until now, so am unaware of how the IT based parts work in that situation.

That has been my question all along - what is the recommended part(s) for a removable application.

Elizabeth

0 Onyx Ahiakwo over 4 years ago in reply to Elizabeth Russell

TI__Guru* 76230 points

Hi Elizabeth,

I would recommend the bq27510 or bq27520. The difference between both is mainly just the packaging.

thanks

Onyx

0 Elizabeth Russell over 4 years ago in reply to Onyx Ahiakwo

Prodigy 220 points

Thank you.

Elizabeth

Power management

Power management forum

Recommendation for a Fuel Gauge