BQ40Z50-R2: chemistry ID

Yvan Young

Part Number: BQ40Z50-R2
Other Parts Discussed in Thread: GPCCHEM

In the application of BQ40z50RSMS-R2 , the chemistry ID of the cell （Molicel INR-18650-m35a）is id2986 . We foung the charging voltage is 4.1V, but the charging voltage should be 4.2V.

What is the reason？and How do we get the right chemical ID？

over 2 years ago

0 Shirish over 2 years ago

TI__Guru 57697 points

Hello Yvan,

According to datasheet of Molicel INR-18650-m35a charging voltage is 4.2V. Can you explain what you mean by "We found charging voltage is 4.1V"?

0 Yvan Young over 2 years ago in reply to Shirish

Prodigy 30 points

Hi Shirish,

The voltage is 4.1V in id2986, the chemistry ID of the cell （Molicel INR-18650-m35a）. You

can analyze the data of id2986.

0 Shirish over 2 years ago in reply to Yvan Young

TI__Guru 57697 points

Hello Yvan,

Can you provide reference to where the charging voltage is specified for ID 2986?

0 zhenqiang Yang over 2 years ago in reply to Shirish

Prodigy 30 points

Hi Shirish,

That's the problem I met also. Please see the last column of the figure, it shows 4.1V in the description. For our application, we need to charge to 4.2V. So ID2986 looks not fit for us. Cell may not be balanced if its voltage reached 4.1V, and the gas gauge is not accuracy if use ID2986. Can TI bulid a new chemistry ID for Molicel INR-18650-M35A for 4.2V application?
Thanks!

0 Shirish over 2 years ago in reply to zhenqiang Yang

TI__Guru 57697 points

Thanks for pointing this out. We will review.

0 Shirish over 2 years ago in reply to Shirish

TI__Guru 57697 points

Hello,

The cell was characterized at 4.1V and we do not recommend using that ID for 4.2V

Instead I would run a chemistry selection test with 4.2V charging and choose the closest chem ID match for the project using GPCCHEM tool instead of ID 2986.