This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Can I use BQ2084-V150 without BQ29312A ?

Other Parts Discussed in Thread: BQ2084-V150, BQ29312A, BQ27500, BQ27200, BQ27210, BQ27510-G2


I have ordered a sample of BQ2084-V150, because I have to make a remote controller with a microcontroller powered by a battery, and I wish to measure the fuel gauge in my 10Ah Li-Po Battery ( One Cell - 3.7-4.2V ), and decide whether to use this one, or another one, only 1.3Ah with my remote.

I've looked on the datasheet before the order, and it seemed to me that I can use it without the BQ29312A IC, but now when I am designing the PCB layout, I look again and have a few doubts.

The facts:

I just want to see the capacity in my battery something like the bq2048 does: when I press a button ( the DISP pin on the 2048 ) I want to see how many LEDs are on/off. This I want to do with my microcontroller. Send a signal on the DISP pin, and then read the signals on the LEDx pins of the 2048. But can I do this without the bq29123A ? I don't seem to find any schematics or application notes regarding that ( i don't have a bq29123A yet, and I don't wish to order and then not to use it ).

If I can, can you tell me where to put the input on it ( my battery BAT+ and BAT- ), and what other components to use ?



Adrian-Ioan Lita

University POLITEHNICA of Bucharest

  • Adrian,

    We have many different families of fuel gauges, but I can't think of any good solution for  a single cell with LED display. If you are going to just read the signals on the LED pins, then it might be better to "talk" to the gas gauge over I2C or HDQ to get the report of remaining capacity. Have a look at the bq27200 and bq27500 families. These are single cell gauges that should work for you.



  • Doug is correct that you will probably want to look at our newer fuel gauges for single-cell batteries.  They do not require an analog front end IC.

    This old post and this other old post might help you choose between a couple of the single-cell families.  To narrow it down to only two choices, I would suggest you compare the bq27210 (from the bqJunior family) and the bq27510-G2 (from the Impedance Track family). 

    Also watch the videos linked in the second post I listed to get an idea of the process of configuring an IT gauge.

    Once you have your gauge configured, you can use your microcontroller to read the data from the gauge and then control some LEDs or other display.  Some sample MSP430 code to talk to our gauges is in SLVA413a.

  • Thank you both for your replies.

    I shall take a look and decide what do use.