BQ27427: Primary Charge Termination Algorithm & Taper Rate

Vadim Aleynikov

Part Number: BQ27427

Tool/software:

Hello,

The conditions of Primary Charge Termination Algorithm and Taper Rate are not quite clear. Please clarify the following:

In the Table in 7.4.2.3.10, the Taper Rate unit is defined as "0.1 h rate" but below the Taper Rate is compared with IRateAvgx.
1. Is the Taper Rate dimension Time (h)? If not, what is the correct dimension of the Taper Rate?
2. What is the dimension of the IRateAvgx?
The second requirement to qualify for Primary Charge Termination is:
"During the same periods: Accumulated change in capacity per 40-second period"
but this doesn't contain any requirement. What is the requirement related to "Accumulated change in capacity"?

Best regards,

Vadim

2 months ago

0 Alan Frias 2 months ago

TI__Mastermind 28325 points

Hello Vadim,

This question has been assigned and will be followed up when possible.

Thank you,
Alan

0 Dominik Hartl11 2 months ago

TI__Guru 63146 points

#1: Taper Rate is in 0.1h rate. It specifies a current threshold relative to DesignCapacity [mAh]. Taper Current [mA] = DesignCapacity [mAh] * 10 / TaperRate [0.1h].
The gauge checks if the average current falls below this Taper Current [mA] threshold. Or you could interpret this as the gauge checks if the average current rate IRateAvgx [0.1h] exceeds the Taper Rate. It's more intuitive using the Taper Current [mA] instead of IRateAvgx [0.1h].

#2: The requirement is that the accumulated charge exceeds 25/256 mAh = approx. 0.1mAh.

0 Vadim Aleynikov 2 months ago in reply to Dominik Hartl11

Prodigy 60 points

Hello Dominik,

Thank you for the explanations.

Best regards,

Vadim

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BQ27427: Primary Charge Termination Algorithm & Taper Rate