BQ35100: Lithium Thionyl Chloride (Li-SOCl2) chemistry characterization

Hello Rene,

All the battery chemistries we have characterized can be found after updated the chemistry ID database (you can use the updater to add the new chemistries) For primary cells we recommend you use the exact battery, it looks like we have not characterized those batteries yet, I would recommend using one of the characterized batteries to use the bq35100 in your application.

Sincerely,

Wyatt Keller

The EVE ER34615 was part of the chemistry ID database under chem ID 615, which is now obsolete. According to the database version 838, chem Id 615 is replaced by 651, but 651 is not part of the database version 838.

Regarding the Tadiran SL-2780 (TL-5930), how can this be characterized and added to the chemistry ID database? Do you have a specific procedure for characterizing primary batteries?

Regards,

Rene

Hello Rene,

I'm checking with the chemistry ID team, it looks like it may have been a issue with it being included in the updater or the wrong one was referenced for chem ID 615.

We try to update batteries as they come out. If you are using EOS mode then the Ra table can be created if you take measurements during discharge at specific DOD points and fill the Ra table with those values.

Sincerely,

Wyatt Keller 

Hello Wyatt,

Do you have a described procedure including the used equipment on how to create the Ra table for the EOS mode of a primary battery?

Or if TI provides a service to have a primary battery characterized, how and where should this be requested?

The Tadiran SL-2780 (or TL-5930 outside of Europe) has been available for many years, but it is not part of the chemistry ID database. So how can this, or a different part type, be added to the database?

Regards,

Rene

Hello Rene,

It looks like the chem ID was accidentally removed from the database, we are adding it back now, it should be in the next chemistry updater which happens often, I believe it's released once a week or every other week.

To characterize the batteries Ra table you can drain the battery by 11.1% increments and take the measured Z value at each increment until 77.7%, then discharge by 3.3% and take Measured Z values at each increment. Then upload these values to the Ra table.

If we get a large demand for the battery we will characterize it.

Sincerely,

Wyatt Keller

Hello Wyatt

Can this characterization procedure be performed using bqStudio and a BQ35100EVM board, of should another setup be used? And can this be automated within bqStudio? Draining a 19Ah battery takes some time and collection the data points at the right percentages should be done carefully, I think.

Should the battery be drained using a constant current or in bursts like the BQ35100 likes to be used?

Regards,

Rene

Hello Rene,

Yes it can be performed with the EVM. bqStudio can't automate the process yet.

The problem has been fixed in the updater, chemID 651 should be available by the end of this week.

Sincerely,

Wyatt Keller

Hello Wyatt,

As of when will the characterization of primary batteries be part of bqStudio?

And when this is available in such an automated form, could this be accompanied by an instruction document describing which procedures should be followed?

Regards,

Rene

Hello Rene,

Usually we don't recommend performing your own characterization for primary cells because you need accurate equipment and lots of time, it's always best to go with a battery with matching chem ID for primary cells.

If we incorporate it in bqStudio it would have documentation.

Sincerely,

Wyatt Keller

Hello Wyatt,

According to the Chemistry ID history of the new version 839 the chem ID 651 should have been added: software-dl.ti.com/.../ChemIDHistory.htm

But when version 839 is loaded into bqStudio it is not present. 650 is the highest chem ID in the 06xx range, when sorting the chem IDs.

What has happened?

Regards,

Rene

Hello Wyatt,

I have used this chem ID 651 now with the Tadiran SL-2780 (TL-5930) and also with the EVE ER34615, and in both cases the SOH value drops with 2% after every measurement until it reached 0% but the batteries are not empty. This is however another issue.

But because of this I investigated the Ra Table values of chem id 651 and I found something strange.

In the past chem id 615 was intended for the EVE ER34615, but it is now obsolete and replaced by chem ID 651 which is now part of the chemistry database version 840 and intended for the Tadiran TL-5930. But these batteries are not from the same factory, show I doubt they will have the same chemistry.

I have compared the Ra table of chem Id 651 with all other Lithium Thionyl Chloride batteries of 3.6V and 19Ah in the database to investigate this. All Ra table of the comparable batteries are different, so I again doubt that a EVE ER34615 can be used with a Ra table for the Tadiran TL-5930.

During this small investigation I noticed that the Ra table of chem Id 651 is exactly the same as Ra table of chem id 645, which is a chemistry definition of a custom battery. Has there been a mixup of the values in the database?

During this investigation I also found a few other issues:

• Energizer EL123APVP (Chem id 612) is a Lithium Manganese Dioxide battery and not a Lithium Thionyl Chloride.
• EVE ER26500-SPC1550 (Chem id 626) has a capacity of 8500mA, not 42500mA.
• Tadiran THL-2450 (Chem id 650) is actually a TLH-2450, so a small typo.

Kind regards,

Rene

Hello Rene,

It is possible for different chemistry IDs to have very similar characteristics. Some of the values could have been mixed, I will have to check if this is the case for these specific IDs.

Sincerely,

Wyatt Keller

Hello Wyatt,

I hope to hear from you soon, and have this confirmed.

Regards,

Rene

Rene,

Still waiting to hear back from the chemistry ID team, it may take some time because of the Thanksgiving holiday.

Sincerely,

Wyatt Keller

Hello Wyatt,

Have you heard from the chemistry ID team yet?

Have they also noticed the strange situation regarding chem id 615 (original EVE ER34615) which is superseded by chem id 651 (now named for the Tadiran TL-5930, but the TL-5930 is not an EVE ER34615) and this chem id 651 has exactly the same Ra table as chem id 645 which is characterized for some custom unknown primary battery.

Regards,

Rene

Hello Rene,

I don't have an update from the team yet, I'll follow up with them or look into it myself.

Sincerely,

Wyatt Keller

Hello Wyatt,

Any news or other status updates regarding the potential chem id mix up?

Regards,

Rene

Hello Rene,

I checked with our database, chem ID 651 and chem ID 645 do not have the dame Ra values, when you uploaded the chemistry ID did you click the "read all" in bqStudio? Sometimes it will not update until you manually do it.

I even checked manually uploading to a gauge to see if it was an issue with the chemdat files, but it matches our database and both are different.

Sincerely,

Wyatt Keller

Hello Wyatt,

I have also checked this, and you are right. I don't know what went wrong. I used "read all". So this part is solved. I will be using Chem ID 651 for the Tadiran TL-5930.

Which Chem Id should I be using for the EVE ER34615? It was originally Chem Id 615 but superseded by 651 which is now the Tadiran TL-5930 and which is not an EVE ER34615.

Regards,

Rene