BQ40Z50EVM-561: Power management forum

RUNNING GAO

Part Number: BQ40Z50EVM-561
Other Parts Discussed in Thread: BQSTUDIO, BQ40Z50

Hi,

Thank you for reading my question. I am trying to do calibration for Battery Learning Cycle. However I ran into a problem when I set up Pack Voltage, 'pack voltage out of range'.

The HW Set up shows below. We use a Li-Ion battery (4 cells) for Learning Cycle.

Also I attached .gg file for your reference.

Thank you for your time.

Best,

Rayna0122-DA.gg.csv

over 4 years ago

0 Nick Brylski over 4 years ago

TI__Mastermind 19195 points

Hi Rayna,

Is the pack voltage actually 3mV? This is quite low.

Best regards,

0 RUNNING GAO over 4 years ago in reply to Nick Brylski

Prodigy 250 points

Hi Nick,

Yes, the pack voltage is measured by meter with reading 3mV. I guess it is because we have no charger/load in between pack + and pack- as the charger is connected to the battery white port end. Please see HW connections below.

0 Nick Brylski over 4 years ago in reply to RUNNING GAO

TI__Mastermind 19195 points

Hi Rayna,

Would recommend you apply a charger with known voltage to calibrate pack.

Best regards,

0 RUNNING GAO over 4 years ago in reply to Nick Brylski

Prodigy 250 points

Thanks Nick. We reworked the connection as you suggests.

After placing the charger in between Pack- and Pack+, we get the Pack Voltage reading as what we set (19V). For battery learning cycle, we are at charging status. One question regarding the current, from the log BQStudio recording, the current reading is consistently 0. Same as the reading we got from meter. Please advise. Thank you very much.

The log file and .gg file from BQStudio are attached for your reference.

0125-Log.log 0125.gg.csv

0 Nick Brylski over 4 years ago in reply to RUNNING GAO

TI__Mastermind 19195 points

Hi Rayna,

Looking at the voltage the device is not charging/discharging so it makes sense for their to be no current.

Best regards,

0 RUNNING GAO over 4 years ago in reply to Nick Brylski

Prodigy 250 points

Hi Nick,

We measured the voltage between Pack+ and Pack- pins on EVM board. The voltage is 19V which means the charger does provide power. However the current reading from EVM is 0, looks like the module is in idling mode or switch off to receive the current.

Best,

Rayna

0 Nick Brylski over 4 years ago in reply to RUNNING GAO

TI__Mastermind 19195 points

Hi Rayna,

Please attach registers and bit register image.

Thanks,

0 RUNNING GAO over 4 years ago in reply to Nick Brylski

Prodigy 250 points

Hi Nick,

A suspicion that 'if two BQ40Z50's work together, could it cause the current is 0?'. I would like to fill in more info to you that our battery, also has BQ40Z50 embedded, same as the evaluation module. So basically, we have 2 gauges work together, could it be the reason cause the current is 0? If so, how to redesign the hardware set up. Please advise.

Btw, I attach the .gg file for your reference. 6644.0125.gg.csv

0 Nick Brylski over 4 years ago in reply to RUNNING GAO

TI__Mastermind 19195 points

Hi Rayna,

Do you have a schematic of this I can look at?

Thanks,

0 RUNNING GAO over 4 years ago in reply to Nick Brylski

Prodigy 250 points

Hi Nick,

The problem is solved after removing one BQ40Z50 gauge. I will mark this question as 'Solved'.

Thanks again for your support all the way.

Best,

Rayna