No output power with bq20z45 EVM

Thiebaut Benjamin

Hello,

I have buy a bq20z45 evaluation board with an EV2300 for use lipo 3s pack ( 11.1v / 7000mAh). I upload data to the evm with bqEASY software but when measure the output voltage is equal to 0v. And when I connected the sys pres to ground I have the same result.

Do you know about this problem?

thank you for answer

over 9 years ago

0 Mike Ewer over 9 years ago

TI__Intellectual 2650 points

Did you wake the part by briefly connecting top of highest cell to pack + before you ran the EVSW

Have you got the unused cell 4 connection on EVM connected to cell3

Have you ticked the keep scanning box in the EVSW SBS window, can you send us a screen shot of EVSW

0 Thiebaut Benjamin over 9 years ago in reply to Mike Ewer

Prodigy 40 points

Thank you for your answer.

Yes, I have wake the EVM.

I have make a test with unused cell 4 connected to cell 3 but I have the same result.

I join two screenshot one for flag and seconf for static data

0 Mike Ewer over 9 years ago in reply to Thiebaut Benjamin

TI__Intellectual 2650 points

Can you clarify what you mean by "but when measure the output voltage is equal to 0v ". I don't think I understand what you mean and cannot see what you mean from the creeen shots. Where is the output = 0V ? Cell 4 is 0V which we expect , but the other 3 cells looks okay and the pavk voltage looks okay , ie equals the sum of the 3 cells.

0 Thiebaut Benjamin over 9 years ago in reply to Mike Ewer

Prodigy 40 points

I take output power here :

On the first and last pin , I want to use it to connect a step-up converter supplied to a intel nuc

0 Mike Ewer over 9 years ago in reply to Thiebaut Benjamin

TI__Intellectual 2650 points

Ok, I understand your issue.

At the moment the problem is that the CHG and DSG FETs are off as shown by the FET control register here

Have you enabled IT by sending 0x21 to MAC access 00 yet? Until you do this the FETs will not turn on automatically and this is usually done during your golden learning cycle. On the DATA FLASH screen, under the 'Gas gauging' tabs what is the value of update status ? If it is 00 or 02 then IT is not enabled yet.

If you want to turn the FETs on manually you can do this by going to the PRO screen and writing SMB Command 46 with data 06. But I would recommend you go through a learning cycle to get the gauge set up before you start trying to connect your load to it.

You may want to read this , especially sect A.2.2

3362.slua421a quick start guide for bq20zxx family gas guages.pdf

and if you haven't done the learning yet then this document , top of page 2 procedure ' for no known QMAX ' is best to follow

5773.slua334b preparing optimised default flash constants for specific battery types.pdf