BQ34Z100-G1: LOW TEMPERATURE PERFORMANCE

unai sanchez

Part Number: BQ34Z100-G1
Other Parts Discussed in Thread: GPCRB, GPCCHEM

Hi all,

We have been using the bq34z100-g1 with LiFePO4 batteries for years with an acceptable result. But now, we are trying to use it with new LiFePO4 batteries that can be charged from -20ºC and we are seeing strange behaviour (SoC and FCC drops at low temperature).

I have read somewhere that a new golden image or learning cycles should be done for working at these temperatures. Is this true? where can we get more info about this?

Best regards,

over 2 years ago

0 Shirish over 2 years ago

TI__Guru 57697 points

Hello Unai,

Use the GPCRB tool to optimize low temperature performance. Then you can do a learning cycle and take a golden image.

0 unai sanchez over 2 years ago

Prodigy 220 points

Hi,

we have seen with that method, we have the news values of Ra, Qmax...then now, would it be necessary to make a golden image from scratch? beside this, what the "reistance temperature compensation optimizer, rev=1,5" is?

Best regards,

0 Shirish over 2 years ago in reply to unai sanchez

TI__Guru 57697 points

Hello Unai,

I would recommend creating the golden image from scratch for best accuracy. The rev=1,5 is the revision number of the tool that processed the data.

0 unai sanchez over 2 years ago in reply to Shirish

Prodigy 220 points

Hi,

So when we do the goldenImage from scratch at room temperature, what RA, Qmax... do we leave as final? The one taken at this time or the ones have given us previously with this low temperature method?

best regards

0 Shirish over 2 years ago in reply to unai sanchez

TI__Guru 57697 points

Hello Unai,

Program the low temperature gg file before starting the learning cycle. The values you get after learning will be the golden values

0 unai sanchez over 2 years ago

Prodigy 220 points

Hi,

I'd like to know if in the file "roomtemp.csv" we have to send the ".csv" that was sentó to get the chemistry of the battery at room temperature.

Files to send:

                        • config.txt
                        • roomtemp.csv -- (this)
                        • lowtemp.csv
                        • gg.csv

best regards

0 Shirish over 2 years ago in reply to unai sanchez

TI__Guru 57697 points

Hello Unai,

Refer to the GPCRB user guide

Excerpt

The tool requires two log files of a charge / relaxation / discharge /relaxation test performed under load and heat exchange conditions similar to an actual device, or ideally inside the actual device. Log files are recorded at room temperature and low temperature starting conditions.

The roomtemp csv for GPCCHEM is at C/10 rate and not at actual load

0 unai sanchez over 2 years ago in reply to Shirish

Prodigy 220 points

Hi,

I have already received the results of the low temperature test. Regarding the "T rise" and "T time constant" parameters, what do they induce in the operation?

best regards

0 Shirish over 2 years ago in reply to unai sanchez

TI__Guru 57697 points

Hello Unai,

I will assign this thread to an expert

0 Steven Yao over 2 years ago in reply to unai sanchez

TI__Genius 12215 points

unai sanchez

These 2 parameters are used to predict the temperature under given load in discharge from present moment onwards, with predicted temperature available, predicting the Ra and Remaining Capacity would be possible.

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BQ34Z100-G1: LOW TEMPERATURE PERFORMANCE