Connecting Li-ion battery pack to bq20z40evm

Shishir Nagendra

Other Parts Discussed in Thread: BQEVSW, BQ27541-G1, BQ27520-G4, BQ34Z100, BQ20Z40

Hi,

I have a 3-cell and 4-cell Li-ion battery pack which is completely sealed and only 2 wires(positive & negative terminals) are provided. How do I connect this to BQ20Z40EVM board through the terminals provided for individual cells?

Also, in bqEVSW, when i select DataFlash, it shows that the configuration file does not match the detected target.

Thanks,

Shishir

over 12 years ago

0 Onyx Ahiakwo over 12 years ago

TI__Guru* 76230 points

Hi Shishir,

You will have to use a different gauge for this such as our 1s gauges. This is because the bq20z45 is designed for 2-4s cells that have their leads accessible to be connected to the voltage input pins of the gauge to monitor each of the individual cell voltages as well as Qmax. In your case, since only the positive and negative terminals are accessible, they will have to be treated as a 1 cell pack.

thanks

Onyx

0 Shishir Nagendra over 12 years ago in reply to Onyx Ahiakwo

Prodigy 50 points

Hi Onyx,

Thanks for the reply.

Can you please suggest other eval boards for the same that is suitable for my application.

Thanks

Shishir

0 Onyx Ahiakwo over 12 years ago in reply to Shishir Nagendra

TI__Guru* 76230 points

Hi Shishir,

There is a plethora of options for you to choose from. A few worthy of mention are the bq34z100, bq27541-G1, bq27520-G4 etc.

thanks

Onyx

0 Shishir Nagendra over 12 years ago in reply to Onyx Ahiakwo

Prodigy 50 points

Hi Onyx,

Thanks for your reply.

You have mentioned that I will have to treat the battery as a 1-cell pack. I need to measure the SoC using the bq20z40evm and bqEVSW software. How can I do that? Is it possible?

Thanks

Shishir

0 Onyx Ahiakwo over 12 years ago in reply to Shishir Nagendra

TI__Guru* 76230 points

Like I mentioned earlier, it is not possible with the bq20z40 but it is with the other devices i mentioned. pls refer to their user guides and technical reference manuals on their Usuage.

thanks

Onyx

0 Shishir Nagendra over 12 years ago in reply to Onyx Ahiakwo

Prodigy 50 points

Thanks a lot Onyx.

0 Shishir Nagendra over 12 years ago in reply to Onyx Ahiakwo

Prodigy 50 points

Hi Onyx,

Please find the attachment for our example configuration of Li-ion battery. The diagram shows that we have access to only +ve and -ve terminals of the battery pack and we do not have any access to internal cells information. So, can we use bq34z100 IC for this type of configuration to measure SoC of the battery?

0 Onyx Ahiakwo over 12 years ago in reply to Shishir Nagendra

TI__Guru* 76230 points

Yes you can.

thanks

Onyx

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Connecting Li-ion battery pack to bq20z40evm