BAT_DET and learning cycle

MariaC

Other Parts Discussed in Thread: BQ27425-G2A, BQSTUDIO, EV2400

Hello,

I'm trying to run a learning cycle by a bq27425-g2a on a 2200mAh Io-Li battery.

I started with the RESET and the BAT_INSERT commands, after I discharged the battery to 3V with a 450mA, waited until VOK and RUP_DIS were cleared and OCVTAKEN set so I suppose the first valid OCV has been taken.

Control Status: 0x0018

Flags: 0x01AE

But when I start the charge the battery goes out from the SLEEP state and BAT_DET is cleared. I can't continue the learning cycle with BAT_DET cleared, as the battery is not anymore detected. Where am I wrong?

Thanks in advance

over 9 years ago

0 MariaC over 9 years ago

Prodigy 140 points

I add the bqStudio screenshot, with the battery discharged:

Thanks again

0 Dominik Hartl11 over 9 years ago in reply to MariaC

TI__Guru 61536 points

What's your circuit on the BIN pin? What's the content of the OpConfig register?

0 MariaC over 9 years ago in reply to Dominik Hartl11

Prodigy 140 points

Hi Dominik, thank you for your help.

The BIN pin is just connected to the pin Vcc through a 1.8M resistor.

OpConfig: 0x5efe.

Here's the screenshot from the NVM after relax:

0 Dominik Hartl11 over 9 years ago in reply to MariaC

TI__Guru 61536 points

Why did you set OpConfig to 0x5EFE? RSVD0 must be 0 and RSVD1 must be 1 for proper operation. If you have and external pull-up on BIN then you can set BI_PU_EN to 0. See Table 8 in www.ti.com/.../bq27425-g1.pdf.

Please change this to 0x09FE

0 MariaC over 9 years ago in reply to Dominik Hartl11

Prodigy 140 points

Thank you very much for your help. I changed the OpConfig as you said. I also realised there was multiple I2C access on the fuel gauge from the EV2400 and the processor (I thought I had blocked any access from it). Now it seems working, and I'm starting the Learning Cycle. I hope eveything will be fine!

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BAT_DET and learning cycle