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.

BQ28Z610-R1: Questions about the Chemistry ID Matching

Part Number: BQ28Z610-R1

Hello everyone,

I suspect my batteries are fake, so I'm running a Chem ID Matching.

And for that, I'm following SLVA725A.

Just some questions:

1) SLVA725A says: "Charge using CC or CV charging to full using taper current. (For example, C/100.) Use nominal CC charge rate and CV voltage." - But what if I don't know my battery's C? It should be 3400mAh, but it's probably fake and it's really 1000mAh.

2)  SLVA725A then says: "Discharge the battery at C/10 rate until the minimal voltage (as specified by the cell manufacturer) is reached." - Same here. Which C should I use? 3400?

3) Just to clarify because this always confuses me: Taper Current is the current you get across time when you just apply a constant voltage to the battery to charge it, right? If so, on (1) above:  "...using taper current. (For example, C/100.)", C/100 also means Taper Current on this situation? Sorry for this question, but TI's documentation always confuses me with these statements, specially since english is my 2nd language.

Thanks for your time

  • Hello Eduardo,

    Without knowing the actual battery specifications, it will not be possible to easily setup the cells for finding the chem ID match. You should have the documentation for the cell that can be used to set these parameters, if you are skeptical I would run a cycle using the expected lower capacity and see how much you coulomb count for either a full charge or full discharge so you know what the C rate should be.

    Taper Current is the current value in CV mode when charge completes, that's correct.


    Wyatt Keller

  • Hello Wyatt,

    So which one is correct?

    Taper Current is:

    A) This entire current curve (marked in red) that you get when you charge the battery using Constant Voltage (CV)

    B) The method of charging. (Taper Current charging = Charging the battery with Constant Voltage (CV), that results in the current curve marked in red)

    C) One single current value. (For example: Taper Current is the current value where you end the Constant Voltage (CV) charging)

    I was under the impression A is correct. And the method of charging that generates the Taper Current (the current curve marked in red above) is CV charging.

  • Hello Eduardo,

    There is a taper current region which is also the constant voltage section of charging, that's correct. The taper current value specified in the gauge is the value which you determine the battery to be full. The taper current is a parameter that is common with battery chargers as well, it will stop charge once the current during the CV region is equal to the Taper Current threshold.


    Wyatt Keller