bq27541-g1 chemistry flash data update

The hidden chemistry information is actually proprietary to TI, so we can't release this information publicly. However, it is basically a set of tables that describe the OCV and Ra table across temperature for a specific chemistry. The only way to update the chemistry in the bq27541-G1 is to use bqConfig.

Ok, but if I update the chemistry with bqConfig and create flash image dffs, dmi or dfi with bqConfig,  chemistry update is present in the image, right ? And if I use this image file to update another bq27541-g1 I am updating also chemistry data of the chip, is it correct ?

Thanks

Yes, this is correct. Once you go through all of the bqConfig steps and read out your flash image files you will have a golden file that can b programmed into any other pack and it will contain all relevant chemistry information.

thanks for your answers

I tried to update chemistry with bqConfig from default 0128 to 0107 and bqConfig returns to me always the following error: "there was an error trying to update the chemistry. Please try again. Ra table definition is missing the FirstDataName attribute" (see attached image)

even if there is the error at least the chemistry ID in the flash is updated to 0107

this is my environment configuration:

- bq27541-G1 v2.24

- bqConfig 1.2.5

- adapter version EV2300a v3.1r

what does the error mean ?

If you try downloading the latest bqConfig, does the error go away? http://www.ti.com/litv/zip/sluc378d

I haven't seen the error before, but it may not be affecting the programming if you're getting the ID to update. If you attach a SENC file I can verify if the ID is programmed correctly or fix it if it isn't.

I updated to the latest bqConfig 1.5.2, but this version doesn't seem to recognize the device. In attach the error I get

In attach also the SENC file. Please check if it chemistry is correct for 0107 chem ID

thanks a lot

7774.bq27541-G1_v2.24_Image.senc.zip

I checked the SENC file, and despite the error, the chemistry ID still programmed correctly. You should be fine to continue.

Hello,

Just another question about an issue I am facing using bq27541-g1 with battery Panasonic NCR-18650 (Technology: NNP + HRL, Nominal Voltage: 3600V, Typical Capacity: 2900 mAh)

What I am noticing is that if I totally discharge the battery starting from a full charge state, with the device connected always powered on, the discharging State of Charge graph is linear and is ok, but if during discharge I switch off and after a while switch on the device, when battery state of charge is under about 50% - 40%, I can notice that state of charge updates don't seem so "regular" and there are some fast decreasing of the SOC and can happen that it reaches a low battery value (3% or also 0%) with a battery voltage that in my opinion is not corresponding to this percentage. In this situation SOC remains to this low value for a lot of time before battery reaches termination voltage (2800V)

have you a possible explanation for this behaviour ? a wrong chemistry ? is in your opinion chem ID 0107 correct for the battery I am using or you suggest another one ?

(I am also about to try the 0210 ID which seems to match with the NCR-18650 Panasonic; do I need to perform again the learning cycle or can I rely on the Ra tables previously obtained with the 0107 chem ID?)

in attach you can find bqEVSW exported gg file of the current flash image I am using and related dffs file. Please, could you check if there is something wrong in my configuration and if dffs file contains the right chemistry ?

thank you very much

2211.bq27541-G1_v2.24_Image.zip

Stefano,

I would say your assumption about a wrong chem ID is correct and this is what is causing the SOC discrepancy. ID 210 does look like the correct ID to use for this cell. ID 210 and ID 107 have very different OCV profiles. So, during discharging, the SOC may look accurate. However, after an OCV reading, you will get very different SOC values with the two chem IDs, especially in the 50% range since this is usually the voltage flat region for a battery.

I would suggest programming ID 210 and redoing the learning cycle.