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BQ27520-G4: minimal firmware in order to just get a % of battery

February 23, 2017, 2:09 am
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Part Number:BQ27520-G4

Hello,

The datasheet is very complex. It looks like a one week work just to analyze it and get something useful from that chip.

Do you have some basic and CPU agnostic host firmware examples that would get from the BQ27520-G4, just what I want : a battery percentage ?

The 7 "softwares" provided on your website don't seem to be that kind of thing.

Does that make sense to have such a simple need with that chip ? Can it be used efficiently with rather simple code ?

A quick answer would be appreciated.

thank you.

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BQ33100EVM-001: CHGFET not fully turn on cause P-MOSFET overheat

February 23, 2017, 2:16 am
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Part Number:BQ33100EVM-001

Hi sir,

I have meet an issue about during charging, when during charging and super-cap voltage about ~ 0V , CHGFET we always measurement this point about 2.5V,  cause  P-MOSFET not fully turn on and overheat.

it possible to let this pin close to 0V when charging? 

Thanks!

Jeff

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BQ33100: How to enable its voltage balancing function?

February 23, 2017, 2:19 am
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Part Number:BQ33100

According to the datasheet, a command (0x0021) is needed to enable this function. I wonder the detailed command sequence like following.

Send byte 0x16 to SM bus

get ack

Send command 0x00 to SM bus

....

Do I need issue this command after every power-on?

In addition, is there any other solution to achieve it.

Thanks.

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BQ34Z100-G1: Maximum nominal energy

February 23, 2017, 5:29 am
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Part Number:BQ34Z100-G1

Hi,

I'am using  BQ34Z100-G1 on BQ34Z1xxEVM and EV2300 adapter.

I'm trying to set up the correct registers values for a pack. i'am struggling with the following values :

Configuration/Data/Design Capacity

Configuration/Data/Design Capacity

My pack is a 1S8P LiFePo4 assembly (8 x 18650 1500mAh LifePo4 cells)

Nominal voltage 3.3V

Nominal capacity 12.8Ahr

Nominal energy 42.24 Whr

As a first approach, I used Chem ID 0426 (not the exact brand/model, but seems close enough at first sight)

The datasheet is stating that max supported battery capacity is 29Ahr, so I should be ok on this point and set for my case '12800'

However, the field Design energy seems to be limited to a maximum value of '32767' (mWhr) as per the datasheet. 

Is there something i did'nt get, or I cannot sense the whole energy capacity of my battery pack with the BQ34Z100-G1 ?

I did'nt run the optimisation cycle yet, but assuming I run it, can I get a Qmax value bigger than the 'Design Energy' value ?

Thanks for your help

Regards

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BQ34Z100-G1: Charge efficiency lead acid PbA

February 23, 2017, 11:44 am
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Part Number:BQ34Z100-G1

Support Path: /Product/Development and troubleshooting/

SLUSBZ5B (revised July 2016) explains that the bq34z100-G1 now has flash settings to allow for the fact that charge efficiency in lead acid batteries decreases with state of charge and is influenced by temperature. However, there appear to be many errors in the coverage of this subject throughout SLUSBZ5B. Also, the values provided for charge efficiency calculations in this document (and probably also stored as default in the device's flash memory) are different from those popularly said to apply to real batteries. At full charge and low temperature they might work fairly well, but probably less so in other conditions. Users therefore may wish to change the stored values, and it would be easier for some of us to do this if conversion factors were provided, perhaps in the same form used for table 12 on p29 of SLUSBZ5B. My guess is that Pb Temperature Compensation (subclass 34 and offset starting at 5) would be converted from DF value using the formula 1280 * DF. If so, to convert from temperature increase in K or C (above 25 C) to charge efficiency reduction in something (maybe 0.01% per C) the temperature change is divided by 1280 then converted to Xemics floating point form before being saved in flash. Similarly, my guess is that Pb Reduction Rate (subclass 34 and offset starting at 10) would be converted from DF value using the formula 80 * DF. So, to convert from state of charge increase (above Pb Drop Off Percent) to charge efficiency reduction in something (maybe 0.1% per %) the SOC increase is divided by 80 then converted to Xemics floating point form before being saved in flash. (All these figures are decimal.) However, these guesses are probably completely wrong so I would welcome correction. Whatever information can be provided would be useful in any form, so if someone could just say what the default (or stated maximum) flash contents represent and in what units (0.1% or 0.01% or whatever) then it should be possible to sort out at this end how to make any necessary changes. Thanks for any help you can give. All best, Tim.

For other users (especially those not using the IT evaluation hardware and software) conversion to Xemics floating point is explained inHow EVSW Display the Raw Data V1.03.pdf

e2e.ti.com/.../How-EVSW-Display-the-Raw-Data-V1.03.pdf

There is VB script for conversion on page 4 of slva148a.pdf

www.ti.com/.../slva148a.pdf but the flow diagram on page 8 of SLUA640 should not be trusted.

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BQ40Z60EVM-578: Recommended fuel gauge for 4 lithium-ion batteries in series

February 24, 2017, 2:23 am
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Part Number:BQ40Z60EVM-578

We are developing a portable medical device, powered by a pack of 4 lithium-ion batteries connected in series, and require an accurate estimate of the battery charge. The batteries are exposed to temperatures ranging from 20 to 37 degrees Celsius. We were thinking of the bq40z60, because it also offers battery monitoring and charging. Do you agree? Furthermore, how difficult is it to work with the bq40z60 and its evaluation board? For rapid prototyping, would you suggest a different fuel gauge that is easier to configure and handle? Thanks!

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BQ27500-V120: I2C lines held low after DFI programming

February 24, 2017, 12:10 pm
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Part Number:BQ27500-V120

Hello,

After implementing and running the DFI programming flow described in figures 8, 9, and 10 of Going to production with BQ275xx (slua449f), the gas gauge is keeping the SDA and SCL low. No I2C errors were reported and ROM register 0x66 was 0 every time it was checked during the programming process. Also, I made sure to flash a DFI that matched the firmware version running on the gauge (120).

1) Does this mean that the gas gauge is bricked? If so, is there any way to bring it back into operating mode?

2) What is the recommended way of developing and testing the DFI programming code? I would hate to brick multiple gauges while fixing bugs.

3) If an error occurs at any point during the DFI programming flow, should the gas gauge be left in ROM mode so that it can be fixed via an external tool (e.g., EVSW)?

Thank you in advance for your help.

Andrei

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BQ27530EVM: bq easy button not showed in the bq evaluation software

February 24, 2017, 2:03 pm
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Part Number:BQ27530EVM

Dear all,

oneof my customer is going to generate the golden file for the BQ27530-G1. He is using the evm plus the BQ eval uation software of the BQ27530-G1.  According to  the documentation and the video present in the folder of the part, the software has a sort of wizard to guide the configuration of the part. This tool should start with the bqeasy button. Unfortunately this button does not appear in the GUI.

Can you please suggest any workaround ? Is there an alternative documentation which explain how to perform the steps present in the bqeasy wizard ?

thanks,

Domenico

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RTOS/BQ27621-G1: using bq27621 with CC26xx SDK

February 24, 2017, 2:41 pm
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Part Number:BQ27621-G1

Tool/software: TI-RTOS

I am starting a project using the CC2640 SDK with bq27621 on board.  When I read the datasheet & reference, I am confused with the Control & extended command.

Is there driver available for SimpleLink platform which I can check.

Currently I am using Middleware I2C command to read 2 bytes :

SensorI2C_readReg (0x04, (uint8_t *) &rBuf, 2);

In this case, I only use single byte command (address) to read, it seems to work.

But when I try to read from DEVICE_TYPE (should be 0x0621)

uint8_t wBuf[4]={0,1, 0,1};

SensorI2C_writeRead(wBuf, 4, rBuf, 2);

it does not come back correct, it all zero

Thanks for advice

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BQ40Z60: how can micro-controllers communicate with bq40z60 through SMBus?

February 25, 2017, 1:47 pm
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Part Number:BQ40Z60

hi Everybody,

I prefer to select bq40z60 ( complete power management IC: charger + gauge + protection ) if possible for a portable test equipment.

the IC has only SMBus interface.

is it possible to communicate it with uC and how?

regards,

Rasool

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BQ28Z610: what battery capacity (min) means?

February 25, 2017, 1:56 pm
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Part Number:BQ28Z610

Hello,

I guess this is a very stupid question.

I have been very confused with the Battery Capacity (min) in the search engine, does this value represent the minimal capacity of the battery that I used? Or does it mean that my battery cannot be gauged when its capacity drops below this value? For example, if I want to find a proper gauge ic for a 150mAh LiPo battery, can I use one with 100mAh minimal battery capacity? Would it stop gauging when my battery is depleted below 100mAh?

Many thanks,

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BQ40Z60: is it possible ti use bq40z60 with 1 cell?

February 25, 2017, 9:30 pm
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BQ28Z610: where should to be connected the adapter and the load?

February 26, 2017, 1:36 am
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Part Number:BQ28Z610

hi Everybody,

i am working on a battery based system with bq28z610 ( complete charge management+ gauge + protection IC ).

there is a simplified schematic in the datasheet:

where am I to connect the adapter and the load?

is bq28z610 a charger IC?

regards,

Rasool

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Linux/BQ27441-G1: how to prevent bq27441 from learning

February 26, 2017, 2:33 am
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Part Number:BQ27441-G1

Tool/software: Linux

hi , all

As I have done the learning cycle with bq27441-G1A, and the data memory is loaded with the exported parameters(Qmax cell & Ra Table updated).

But after I discharge and charge, the FCC and RC always changes a lot.

As we all know IT algorithm inside bq27441 is enable automatically, which means it's always learning. This will result in unstable capacity to end-user.

Could anyone tell me how to get rid of this trouble? Thanks!

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BQ34Z100EVM: 3s 5000mah lipo battery fuel gauging with 30 Ampere discharge. Will it work?

February 25, 2017, 5:16 am
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Part Number:BQ34Z100EVM

Hi all,

Im a newbie to the power management world.!

I'm currently working on a project that requires a 5000mah 20-30 C 11.1 v 3s lipo battery to be charged and discharged simultaneously. 

My load is a motor which draws a continuous current of 20 A & i need a fuel gauge to find the SOC of my battery.

I thought i could get a 30 A 3s BMS and wire the fuel gauge onto it. How ever after going through various TI bq series data sheets i'm all the more confused. 

I dont get it. The datasheet says the maximum charge & discharge current is 7 Amps while my load draws about 20 Amps. 

Is there any way to find the SOC of my battery with a 20 amp discharge. Please do suggest me with some ideas. 

Thank You..!! 

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Linux/BQ27441-G1: please help me to get CHEM-ID for my battery cell

February 26, 2017, 6:14 pm
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Part Number:BQ27441-G1

Tool/software: Linux

(Please visit the site to view this file)here is the charging and discharge log data, please help me to identify the CHEM-ID, thanks!

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BQ30Z554EVM: BQ30Z55

February 26, 2017, 11:20 pm
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Part Number:BQ30Z554EVM

Hi,

I want to do some development with BQ30Z55.

Is it mandatory to use EV2300 or TI make USB-SMBUS interface only ?

Can we use any other third party USB-SMBUS interface ?  

I am using BQEVSW software.

Regards

SID

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BQ27426: Current sense resistor

February 27, 2017, 1:56 am
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Part Number:BQ27426

Hi,

We are considering bq27426 as a battery gage for a custom tablet we are developing. The problem we are facing is the maximum design capacity that can be set on the IC. It is fixed at 8000mAh but we have 8800mAh batteries. Furthermore our charging current will be 3A and we are not certain that the gage can measure that current with 10mOhm resistor.

If we place a 5mOhm resistor instead of 10mOhm and divide the design capacity and design energy and taper current by 2 would the gage measure battery percentage correctly. As far as I know there arent any registers for setting resistor value.

Thnak you in advance

Martin

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Linux/BQ27542-G1: Android kernel driver reporting spurious(wrong) capacity ,voltage and current values

February 27, 2017, 2:36 am
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Part Number:BQ27542-G1

Tool/software: Linux

Hi Support Team,

In our project we are using,

- bq27542-g1 fuel guage,

- Li-Ion 6000mAh battery.

Every 1 min we logging the capacity,voltage and current values, now and then when we read capacity,voltage and average current we get spurious values.

Can you please check the kernel driver and update me why this is happening?

I am attaching the Android kernel driver we are using. Please review the kernel driver and give your valuable inputs.

If there is any particular kernel driver available for bq27542-g1,please share . We will use the same in our build and test.


(Please visit the site to view this file)

(Please visit the site to view this file)

Thanks,

Dayananda KT

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BQ20Z655-R1: ChemID Help

February 27, 2017, 5:49 am
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Part Number:BQ20Z655-R1

I am am having issues with MathCAD and identifying the ChemID. Can I send in cells for evaluation?

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