BQ40Z60EVM-578: unable to charge after partial discharge

LIAN DAI59

Part Number: BQ40Z60EVM-578
Other Parts Discussed in Thread: BQSTUDIO

I'm using BQ40Z60EVM-578 to evaluate our NCR 18650B, lithium Ion battery, 4 series, so the final output is 3.7v*4.

Power supply: BK precision 1762 DC power supply. Set output to 20V, current output is set to max.

Load: 40ohm resistor.

I just found an issue regarding not resuming charge. The battery pack was fully charged, and partially discharged around 2481mAh(remaining capacity). Then I turned on the external power supply, but it seems it won't resume charging as the charging current is 0mA. The external power supply only supply power to the resistor load.

I attached my log and data memory export.unable to charge after partial discharge.zip

Any idea?

over 8 years ago

0 Sammi Shang over 8 years ago

TI__Expert 4450 points

Hello Lian,

It seems the OC bit has been set which means over charge protection.
You could take TRM P22 as reference.
www.ti.com/.../sluua04c.pdf
Thanks.

Best regards,
Sammi

0 LIAN DAI59 over 8 years ago in reply to Sammi Shang

Intellectual 590 points

Hi Sammi,

Good point. As of right now, the remaining capacity is less than 2386mAh vs.2891mAh[full charge capacity], which is less than the default OC setting, why won't it automatically recover? And how to recover?

Lian

0 LIAN DAI59 over 8 years ago in reply to Sammi Shang

Intellectual 590 points

I made a Low-high-low transition on SYSPRES pin, and it reset the OC flag. Is there anyway to let the chip automatically recover? In the real world, once the fault occurs, the customer won't be able to know how to reset it manually.
Lian

0 Sammi Shang over 8 years ago in reply to LIAN DAI59

TI__Expert 4450 points

Hello,

Manually turn off using AFE_CONTROL[CHGEN]=0. Take datasheet P24 as reference.
www.ti.com.cn/.../bq40z60.pdf

Thanks.
Best regards,
Sammi

0 LIAN DAI59 over 8 years ago in reply to Sammi Shang

Intellectual 590 points

Hi Sammi,
do you know where i can find the AFE_CONTROL[CHGEN] in the bqStudio?
I can't find any reference of the AFE CONTROL register in TPM(www.ti.com/.../sluua04c.pdf), so I'm unable to revise the value.
Lian

Power management

Power management forum

BQ40Z60EVM-578: unable to charge after partial discharge