Part Number:BQ27441-G1
When I send the set capacity command, it changes the design capacity, but the other numbers don't update for quite a while. Is there some way to force it to update the other values? Is it possible to have the chip remember the last values it had so the numbers are available on boot?
Part Number:BQ78350-R1
Hello,
I'm quite familiar with other older CEDV gauges, and the capacity synchronization to FCC (with RSOC=100%) at charge termination, by reaching a voltage and current threshold during charge current tapering down.
This feature is handy and always present the battery at 100% to the user.
On studying a new 7S pack based on bq78350-r2 fw 2.01 build 25, I have difficulty to reach the same sync effect and RSOC does not reach 100%.
All the battery settings are correctly set:
CEDV Gauging Configuration:
CCT=1
CSYNC=1
SC=1
Advanced Charging Algorithm - Termination Config:
Charge Term Taper Current: 40mA (meaning 400mA, because I have IPSCALE0 =1)
Charge Term Voltage = 100mV
I noted during several test that the gauge never sync when the current taper down and reach those thresholds.
On doing other tests with different settings I noted instead this:
Setting Charge Term Taper Current: 200mA (meaning 2000mA because of IPSCALE0=1), the Valid Charge Termination is met after 40s the Average Capacity is below ~116mA (meaning 1160mA)
Setting Charge Term Taper Current: 100mA (meaning 1000mA because of IPSCALE0=1), the Valid Charge Termination is met after 40s the Average Capacity is below ~60mA (meaning 600mA)
Setting Charge Term Taper Current: 80mA (meaning 800mA because of IPSCALE0=1), the Valid Charge Termination is met after 40s the Average Capacity is below ~20mA (meaning 200mA)
Please note the attached charts taken during my tests (the Remaining capacity was artificially dropped by hand before each run, in order to simplify the test).
Question:
what are exactly the conditions to met the valid charge temriation ?
The voltage threshold is ok, all cells are > 4200-100 = 4100mV
How is the current interpreted ?
Does the IPSCALE setting interfere with the calculations ?
Thanks in advance
Pietro
Part Number:BQ40Z60
When trying to preform a learning cycle, once I get to the part where I am supposed to fully charge the pack, I Cell 4 voltage climes up over 4200mv while the other 3 cells are still at ~4050mv +-30mv.
If I continue to charge the over voltage protector IC (BQ294700) will drive the FUSE pin before the BQ40z60 does anything.
1.) Shouldn't the BQ40z60 stop charging when any cell is higher than the COV Threshold (4300mv) before the protector IC blows the fuse (4350mv)?
2.) Shouldn't the BQ40z60 balance by bypassing cell 4 and not allow it to reach 4200mv?
Part Number:BQ34Z100-G1
Hello,
I have several questions regarding the BQ34Z100-G1 evaluation module, more specifically on integrating the calbration/golden image on higher scale volumes.
Thanks!
Part Number:BQ27441-G1
Hello evereone.
i was used 7.4V li-po Battery. and i like to used BQ27441-G1 fule gauge. but BQ27441-G1 pin BAT max voltage 6V.
how can i used BQ27441-G1. can it possible to use a voltage divider.
please provide any reference schematic.
Part Number:BQ20Z95
Hello，
my project：Lithium battery pack fuel gauge
I used BQ20Z95 to process it.
This product has been mass-produced and the product has encountered problems.
1）The calibration coefficient of bq20z95 is automatically changed，resulting in inaccurate current measurement and large current. The CC Gain = 0.706，CC Delta = 0.706，The values of these instructions are wrong. What causes the calibration coefficient to change?
2）You can refer to the attached configuration parameters and calibration coefficient picture.
Thanks.
(Please visit the site to view this file)
Part Number:BQ28Z610
Hi all, I'm trying to integrate this fuel gauge into our product and am having trouble with writing to the data flash region. I am able to read values and they are as expected but writing has no effect. For example for register 0x4600 (FET Options) I do the following to read:
[Start Condition] [I2C Write] [0x3E, 0x00, 0x46] [I2C Read] [0x20]
Which reads 0x20 as is the default value. Then I attempt to write the value:
[Start Condition] [I2C Write] [0x3E, 0x00, 0x46, 0x00]
However when I read the value back again I still read 0x20. Am I missing something? Does something need to be enabled to allow me to write?
Part Number:BQ40Z50-R2
Hello,
I need help with this customer issue:
I am digging into battery failure modes and discovered that I needed to change a few settings to prevent our drones from falling out of the sky from an under voltage cutoff event.
I set:
This is correctly causing the % remaining to go to 0 and prevent a pack with a bad cell from cutting off in the air.
But, I am seeing this same behavior on some packs with good cells. If you look at these logs, you'll see that the voltage did not dip low enough to cause the Cell Term event but the % remaining drops like a rock.
When I hook these packs up to the Battery Management Studio after the flight, they show 0% remaining, 15V+, and true remaining Q of 1500mAh+.
Any ideas about this would be helpful.
I have plenty of other data I can share offline (flight data, srec, etc)
Regards,
Ryan B.
Part Number:BQ40Z50
Hey all,
This is in regards to the learning cycle needed for accurate SOC prediction for BQ40z50 fuel gauge. We have tried to perform two learning cycles, the most recent with just 1 cell (DA configuration register was updated to reflect the number of cells in series).
1) Final Update Status not matching the doc: Upon commencing the learning cycle, we found the process to register values were going as expected, i.e. the update status was 0x05 after the charge cycle, however after the C/5 discharge (final discharge of learning cycle) our update status is 0x05, not 0x06, as seen recommended in page 5 section 4.2.5 of this manual: http://www.ti.com/lit/an/slua777/slua777.pdf . At this point our update status will stay at 0x05 after waiting for the VOK bit to clear.
2) Full Charge Capacity not matching Design Capacity: When the rest period after the slow (C/5) discharge is done, the full charge capacity only shows 1050 mAh, whereas the Design Capacity was set as 1500 mAh (the rated capacity of the cell). WIll this value update itself automatically as battery is used, or is this incorrect due to improper learning cycle?
3) The manual mentions dataflash values of: Design Capacity, Charge Termination Taper Current, Discharge Current Threshold, Charge Current Threshold, Quit Current Threshold, and Term Voltage must be set for learning cycle to work properly. I wanted to confirm that there are no extra dataflash values in the BQ40Z50 that need to be updated for learning cycle.
Please let us know if you have any suggestions/advice to try out with our next learning cycle.
Thanks!
Part Number:BQ40Z50
Hey all,
When performing a learning cycle we allow our batteries to rest for a recommended amount of time found in the learning cycle portion of this document http://www.ti.com/lit/an/slua777/slua777.pdf.
The problem we have run in to is that when left to rest the battery keeps discharging slowly when not attached to any load or other current drain.
We were curious if anyone had any suggestions, we have tried powering off and disconnecting our load but it seems like overnight the battery will drop .4-.5 Volts below the safe discharge levels for the battery. Has anyone else had problems where other parts drain power? Have they found any solution to it aside from flat-out disconnecting it? The battery, in our case, was connected to the gauge, directly on it, and the gauge was connected to a charger, a microcontroller and an EV2400 unit.
Thanks!
Part Number:BQ40Z50-R2
Hi,
My customer would like to understand how the 5.1Kohm series resistor suggested for the CHG/DSG/PCHG signals are calculated?
Another post states;
1. “The limitation for the DSG series resistance is to limit the DC pin current under a severe reverse charger connection scenario. Select the resistor where the DC current in this scenario is 10mA or less.”
How would one calculate the DC current in this scenario? I’m assuming that a ‘severe reverse charger connection’ would be an unregulated reverse polarity power supply or similar?
2. “For the CHG series resistor, a 1k can be used.”
Also, if the max gate drive current per pin is 10mA, then the 2k internal resistance should be enough to limit this, so why the recommendation for a 1k series external resistance for the CHG FET?
Thanks in advance, Carlo.
Part Number:BQ34Z651
Hi There,
I am writing my own script to update the data flash on my BQ34Z651 devices and I have noticed that there are many regions of the data flash that are undocumented.
So far I have discovered the following:
| SubClass ID | Offset range | Description |
| unknown | unknown | Heater Control |
| 36 | 4-5 | unknown |
| 59 | 24-25 | unknown |
| 59 | 32-39 | Lifetime OT/OV information |
| 60 | 4-6 | Unknown |
| 64 | 12-13 | Unknown |
| 65 | 0 | Unknown |
| 80 | 2-59 | Unknown |
| 80 | 62-76 | Unknown |
| 80 | 85-87 | Unknown |
| 80 | 90 | Unknown |
| 80 | 91-92 | Is meant to be 'Sim Temperature Delta' but it is not there |
I currently haven't looked past Subclass 80, but given my findings thus far I image in that there will be more issues there too.
These undocumented regions (where their location is known) are certainly full of Data when I read from the data flash. I just have no idea what that data is or if it is safe to erase it.
Can anyone help me out?
Thanks,
David
Part Number:BQ27750
Hey,
I'm working on BQ27750 single cell unit in my project and facing some following issue:
1. Communicate the BQ27750 with PSOC 4 micro controller via I2C, when Load is connected DFET and CFET is on after some threshold DFET gets off but still some negative current is shown and battery still get discharge with slow rate. (command is ( 0xAA + 0x3E + 0x20 + 0x00 ) for DFET & for CFET ( 0xAA + 0x3E + 0x1F + 0x00 )).
2. On Every reset the BQ27750 go into the sealed mode. Please tell me the Command of Unseal mode or full access mode and how to write via I2C.
3. On reading Operation_Status Register, it show that BQ27750 is in Reserved mode but I unable to write the register like Shutdown Threshold, Sleep Threshold etc.
Regards
Rahul Kumar
rahul1.kumar@vnl.in
8860719701
Part Number:BQ28Z610
Hello,
Following the opinion of Batt (who I thank once again) I have put in manufacturing the batteries using the procedure outlined in my original post:
when battery packs need to be assembled, then we do:
This procedure, done during design and small pre-series, has worked but now I do not know what could happen -> The manufactured batch has the most of the packs well below the rated capacity, also considering the tolerances of the process but the most strange is that when I attempt to discharge, the Remaining Capacity doesn't change for sometime (and RSoC is 100%), then suddenly it is updated to a value well lower i.e. RsOc goes 57%).
I have checked everything several time (FW, data and parameters and all is exactly like should be.
What hell has happened / is happening? I'm going crazy .....
Any help will be appreciated a lot.
Maurizio
Part Number:BQ40Z80
Hi,
We would like to set LED display control pin to pin 15.
However, when I set MFP15_sel1.0 to 0x01 and then do reset, I don’t see the pin 15 pull hig. ( I also set MSF13_sel2.0 to unused 0x1xx)
Do I misunderstand or loss something?
Part Number:BQ4050
We have recently received batteries using the BQ4050 controller and I am attempting to integrate them into our hardware.
The BQ4050 technical data sheet is inconsistent regarding ChargingStatus().
It appears that the ChargingStatus() description is incorrect. What are the correct contents?
Part Number:BQ34Z950
Hello,
I am using the bq34z950, which has a DQ interface and the standard registers that are available over DQ.
I noticed that when trying to convert NAC to Remaining Capacity, the provided equation does not give the expected result.
According to several datasheets of parts that report NAC over DQ:
NAC = RC() * Rsns * 1/mV to mAh Scale
OR
RC() = (NAC * mV to mAh Scale) / Rsns
My example uses known values for RemCap = 4689mAh as reported through SMBus, mv to mAh scale = 640, and Rsns = 3.359mOhm. The reported value in this case is NAC = 0x2706 = 9990uVh
However, when using the provided equation and reported NAC, the resulting RemCap is 1903mAh, which is only about 40% of the reporetd RemCap.
Can you help me understand why the error exists?
Part Number:BQ27742-G1
Hello ,
I'm asking for your help with following problem:
I have difficulties to read out or access the data flash of the bq27742-G1 with the bq management studio software.
To program chem id or write values to the data flash always ends with an error.
Im getting readings for the bit registers. But there is also some kind of problem to use "Read all" in the "Data Memory" window.
It is working just really rarely if i press that button a lot of times.
Pull ups are attached to SDA and SCL and the signals on the lines were checked and are looking fine.
Can you tell me which frequency the bq studio is using for i2c and how to adjust it? Is there some kind of other error source
what Im not thinking about?
Thank you!