Good morning all,
I am working with a bq34z100 evm and am attempting to write the golden image file to the board in order to correct a calibration error. After importing the file and writing it does not change the values for the calibration that I am looking at. Specifically it is the CC gain and CC delta values I'm looking at changing. Is there another way I should be uploading the golden file or another method to directly write to this memory location?
Regards,
Alex
Hi,
I am designing with the BQ40z60 but not using the cell balancing feature. I am concerned about the VCC on the chip (using an buck regulator off the 24V Adapter). If we don’t use the cell balancing, how is the best way to wire the VC1-4?
Hi everybody,
I use 9600 mAh pack charged at 4,1V with bq27510-g3. I get a golden image with learning cycle at 4,2V and a second at 4,1V. This worked fine until SOH and TTE dramatically decrease.
According to this post step 6, I made a mistake with SOH Load I, left by default.
My question : for the end product, charging at 4,1V, should I set Design Capacity at 9600 mAh (used for learning cycle at 4,2V) or 8640 mAh (90%) to have SOH = 100% ?
Regards, Pierre
Hello,
I actually use a BQ26220 to know the capacity of a non rechargeable battery.
My problem is that the software use to evaluate the BQ26220 don't understand the answer of the BQ26220. I have a communication (See the attachment) between the host and the BQ26220. So I think that the BQ26220 understand the command and answer.
But in the soft i have no data and it is written "RS232 Communication Lost" even if the host send and receive something.
So if someone can help me.
I use an EV2200 to communicate between the BQ26220 Battery manager and the BQ26220.
Thanks you in advance for your Answer
Best regards,
Couturier Vincent
Hello,
I tried to connect via I2c to the BQ76920EVM and BQ76940EVM boards through the EV2300 interface, but I always get the "unable to detect a connected device" error from the bq76940 evaluation software.
Since it's mentioned that the EV2400 has got problems when using bqStudio to evaluate the fuel gauge, I ordered the EV2300.
I have tried using Windows 7 64 bit and Windows 7 32 bit. Both with .NET 4 installed.
I'm confident I didn't miss any steps, and I even installed Windows 7 32 bit to rule out any EV2300 driver issue I might be having on Win 7 64 bit. I don't really know how to debug the issue. Both the bq76920evm and the bq76940evm show the same exact error (the only difference being the applied voltage).
I searched the forums because I presumed not to be the only one having this problem, but apparently I am.
What should I do now to debug the issue? The bq76940 evaluation software prints out nothing in the command line.
Thanks in advance.
We are trying to calibrate the current according to paragraph 11.2.5 in TRM. However, there seems to be some errors in this paragraph. Could you help me figure out how the calibration algorithm should be?
Let me start by stating that I am NOT using the Advanced Charging Algorithm function for our product. But...
For the Low, Standard, High, and Recommended temperature ranges, I've set the voltages to the same value because I believe they are used to determine charge termination, and I also set all the Charging Current settings (Low, Med, and High) to the same value (as recommended by Tom Cosby).
Should I also set up the temperature ranges (T1, T2, T5, T6, T3, & T4) to at least encompass our temperature range, and set the Voltage Ranges (Precharge, Low, Med, and High) to the same value?
I'm worried that there might be some shared values in the Advanced Charging Algorithm that are used to determine other alarms or other conditions that I am using.
Thanks.
tom
The only component I've found that appears to be appropriate for fuel gauging Lithium Primary single cells is the BQ2052. The absolute maximum VCC for the device is 7V. I need to gauge an Energizer 9V Primary battery. Is there either a way to adapt this component to work for the application or another component that would be appropriate for my application?
Thanks.
Hello,
I am brand new to the TI battery chipsets, and have been looking at schematic for the BQ76930EVM. I'm having trouble understanding how the charge and discharge FETs are meant to operate. To my way of thinking the charge FET should be activated when you want to apply a charge from an external power source to charge the batteries, and the discharge FET would be activated when you want to control the output of the battery driving a load. When I look at the configuration on the schematic (Page 44 of SLVU925B) it looks as though both the discharge (for Q2) and the charge (for Q4) FETs would need to be activated to have current flow from J1 to J3. I do see the "PFD" node in the middle that creates an alternate path (through Q17) to J3 using the "pre-charge" control, but it still requires Q2 to be activated. I'm not sure how you would integrate a charge system into this configuration? Does this mean that for most operations both charge and discharge need to be active at the same time (or discharge in combination with pre-charge). Any help would be much appreciated. Thanks in advance.
Dan.
Hello,
We are designing a small off-grid solar power system for single homes in rural areas. I'm considering using the BQ34Z110 for battery SOC monitoring, and I have several questions regarding its application and suitability. answers from TI would be much appreciated!
First, a brief description of the system: a solar panel array feeds a charge controller, which charges a battery pack. The load is an DC-AC inverter which supplies AC to the home. a board will be made that would contain the BQ34Z110 and an MCU. This board will monitor battery SOC and health, will disconnect or limit the load when the battery is too discharged, and will also log various battery parameters for later reference.
preliminary specs:
200Ah, 24V battery pack
40A max charge / discharge current
I have the following questions:
1. Battery compatibility: we'll probably use one of the following batteries (two of them in series, and possibly two series strings in parallel).
http://www.narada-ap.com/products/htb-313k-series-12v
http://www.hoppecke.com/energy-storage/lead-acid/opzv-bloc-solarpower.html
Do you expect that either of these batteries would fit one of the existing chemistry profiles? I understand you cannot guarantee it just from the datasheets, but I'm just trying to understand what is realistic to expect (i.e. probably yes / probably no)
2. In case the existing profiles do not fit, I understand I will need to have two batteries shipped to you so you can analyze them and create a new profile. Does TI charge anything for this process? what would be an expected time-frame for this process if it's needed?
3. Is there a C software library to interface the BQ34Z110? if there is, for which MCU was it written?
4. Evaluation module: I want to use the EVM to test the setup before going to a custom board production, but I see the EVM is not designed for my current levels (sense resistor of 10 mOhm on board seems to be unsuitable for 40A). can I use an external sense resistor instead? is it realistic to get decent accuracy from such a setup?
5. How do I tell the BQ34Z110 which sense resistor was installed? I noticed a register for the ratio of my chosen voltage divider, but not for my chosen sense resistor value (or maybe I missed it?)
6. Algorithm suitability: considering my target application, I'd expect that the charge "cycles" would be short and incomplete, i.e.rapid switching between charging and discharging. This is because both my energy source my load are unpredictable: sunlight comes and goes as clouds move across the sun, and users turn appliances on and off, changing the inverter's consumption from the battery. Generally, I will not have complete, uninterrupted charge cycles, but more like a few minutes of charge, a few minutes of discharge and so on. Now, the datasheet mentions the concept of "charge cycles" a lot (e.g. "the BQ34Z110 will calculate XYZ according to the previous discharge cycle), but as I explained my application will have very intermittent charging. Will this erratic behavior mess with the algorithm?
7. Production: what would I need to calibrate per each manufactured unit? will I need to do a charge / discharge cycle for each manufactured unit for calibration, or just once during development? will changes in the resistance of the high-current path (battery wiring to the board) affect system accuracy? if so, how can I compensate?
thank you for taking the time to read my long post... looking forward for answers so I can go forward with this project!
thanks,
Guy.
Hello, all
Now we have some inquiries regarding remained battery information on BQ27500-V120 from our customer.
Please refer to the item below, and feedback us with your comment.
We released our production with BQ27500-V120. However, some parts have been returned from the market since the remained battery information was not correct.
From our investigation, this root cause was found as some registers information were not correct.
<Normal products for full charged battery>
AverageCurrent: -33mA
RemainingCapacity: 444mAh
StateofCharge: 68%
Unfortunately we could not read FullChargeCapacity directly, however the above information may result in 653mAh.
<Returned products for full charged battery>
AverageCurrent: -7mA
RemainingCapacity: 325mAh
StateofCharge: 92%
Unfortunately we could not read FullChargeCapacity directly, however the above information may result in 353mAh.
For your reference, the initial settings for Qmax and DesignCapacity are both 720mAh.
Please let us clarify about the following items.
1) How we could correct these register values
2) Whether only these related registers could be reset
We thank you in advance for your information.
Best regards,
Hi,
I use the configuration bq76940 + bq78350 for my battery management system. I have used the the optional resistor programmable SMBus Slave Address with R1=39K and R2=100K for REGOUT=2,5V, I get Vaddress=704mV (SMBTAR_ADDR6). I have cleared the register FIXED_ADDR. However BqStudio acknowledge the address 0x17 and it doesn´t answer the new configuration address.
Could you give me a solution? Sorry for my english.
Thanks you.
In looking through the technical reference, it references a document (SLUA420) for a circuit for Fast Balancing. This shows the circuit (roughly) to be used to increase the bypass current and speed up balancing.
This is still passive balancing though. Is it possible to perform any form of active balancing using the BQ40z50?
Alternatively, are there any other products which can be paired with this BMS IC to perform active balancing?
Hello,
Looking at the BQ76930EVM, (Page45) I have a question.
I understand that the VC lines switch between measuring the voltage (presumably presenting a high impedance input to the external balancing circuit) to actively balance adjacent circuits. I understand that the internal circuit can balance up to 5mA between VC lines, but what does the output stage of a VC line look like when in balancing mode and how does it affect the external balancing circuit in EVM?
Thanks.
hi,
can i have 2 separate bq76930 to measure 20 cell battery ?
i am designing bq76930 + mcu in single module which is able to log 10 hours of cell information, and export to pc with csv format, how if i connect 2 modules to 20s battery pack ?
e.g. the 1-10s battery cell connect to bottom module, and 11s-20s battery cell connect to top module, both module will not link together, in this situation can i still turn on balance feature ? if i set target balance voltage to 3.7v although the cell 1 of top battery pack is not connect to cell 10s of bottom battery pack, can i still use this method to make both pack balance ? any risk i may encounter ?
thanks,
tiger
Hi.
I'm currently working on bq34z100 and DFI. I've been able to successfully dump and flash a DFI using a uC.
If possible, it would be great to have a "DFI to parameter" mapping, so that quick changes are possible (e.g. we have a DFI with a Cycle Count value of n, we want to set it to zero, we set location 0x264 and 0x265 in DFI to 0x00).
Does such a document exist?
Thank you very much,
Hi
We are using the BQ34Z100 with 2 series Li-Ion cells (2900mAh).
The charger we are using (I don't think it can be changed) is a single stage charger that cuts off the charge at 8.4V and does not do the second stage saturation charging down to 50mA.
I am currently tying to "teach" the pack prior to production. The problem is the FC bit doesn't get set when charging.
I've set the taper current to 300mA (the chargers seem to stop around 200-250mA), cell taper voltage to 200mV, taper window to 20s and FC Set to -1.
The pack passes the taper current and taper voltage, but the FC bit is never set.
The datasheet says
"The bq34z100 detects charge termination when (1) during two consecutive periods of Current Taper Window, the
AverageCurrent() is < Taper Current and (2) during the same periods, the accumulated change in capacity >
0.25 mAh /Taper Current Window and (3) Voltage() > Charging Voltage - Charging Taper Voltage."
I don't understand how I can read the second requirment, do I need to adjust Min Taper Capacity? Its set to 25mAh
Is it the case that FC will never be set due to single stage charging?
Can I optimise the settings without FC being set, I thought it was required to update an internal parameter, but perhaps I misunderstood this?
Thanks
Morgan
What is a suggested process for bringing a bq27421 design to production? It appears there are many ways to get there.
1. Minimal one would be to just set the four things (Design capacity, termination voltage, design energy and taper rate) and then just let the product go through various cycles in normal use. We are finding this may not necessarily expose the gauge to all the conditions it needs to learn.
2. Perform controlled learning on the bench, and then use Qmax value and Ra tables from that to load to every gauge by their host processors on ITPOR
3. Perform controlled learning on the bench, generate golden image and have host processor load all of it on ITPOR
Comments and thoughts are welcomed!
Hi,
I have checked possibility to use BQ40Z60 in one of our future applications. It, however, is still unclear to me if it could be used as stand-alone charger / gas gauge after programming the flash. Is this possible or does it always need a separate controller?
