BQ27421-G1: bq27421-G1B battery chemistry

Lifeng Jiang

Prodigy 40 points

Part Number: BQ27421-G1
Other Parts Discussed in Thread: BQ35100, GPCCHEM

We're using the bq27421-G1B fuel gauge IC.

The older version of the bq27421-G1 technical reference (SLUUAC5, June, 2013) states:

• bq27421-G1A is pre-defined for LiCoO2 -based batteries for 4.2 V max charge voltage.

• bq27421-G1B is pre-defined for LiMn2O4 -based batteries for 4.3V or 4.35V max charge voltages

The revised version SLUUAC5C (Aug, 2016) states:

• The bq27421-G1A fuel gauge is predefined for LiCoO2-based batteries for 4.2-V maximum charge voltage.

• The bq27421-G1B fuel gauge is predefined for LiCoO2-based batteries for 4.3-V or 4.35-V maximum charge voltage.

• The bq27421-G1D fuel gauge is predefined for LiCoO2-based batteries for 4.35-V or 4.4-V maximum charge voltage.

We're using an IMR (LiMn2O4) battery with the bq27421-G1B fuel gauge. Is the bq27421-G1B accurate enough to gauge the LiMn2O4 batteries?

over 7 years ago

0 Onyx Ahiakwo over 7 years ago

TI__Guru* 76230 points

Hi Lifeng,

For lithium manganese dioxide cells, i would recommend you use the bq35100 and not any of the flavours of the bq27421.

thanks
Onyx

0 Lifeng Jiang over 7 years ago in reply to Onyx Ahiakwo

Prodigy 40 points

Thank you Onyx.

Isn't the bq35100 designed for primary (non-rechargeable) batteries?

I'm looking for a fuel gauge for rechargeable IMR batteries in the 26650 form factor.

0 Onyx Ahiakwo over 7 years ago in reply to Lifeng Jiang

TI__Guru* 76230 points

LiMnO2 is non-rechargeable primary cell, no? is your rechargeable?

If your cell is rechargeable, i would recommend you use our gpcchem tool to determine if the bq27421 default chem ids would be a good fit. If not, then use you will have to use a flash based gauge like the bq27520.

thanks
Onyx

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BQ27421-G1: bq27421-G1B battery chemistry