There are many standards specify how DCR should be measured or calculated. Basically, it needs 2 periods of charge or discharge with different current values. The calculation formula is like that: Rdc=(U2- U1) / (I2 – I1) , U2 and U1 are the usually the very end of the corresponding period.

1, Using our BTS 4000 or those equipment can support 10Hz or above record frequency for such test. Below schedule goes a testing method specified a standard manual.

Cycle-Life-Test-Result

2, Now use DCR (or DCIR) function in BTSDA to load the testing data. Set below computing group for calculation.

DCIR-Calculator

Why BTS 4000 for DCR Test

DCR test is usually brought out in short time. So the equipment’s capability is critical to the testing result. The equipment needs to response fast and has an accurate time control. And as specified in many testing standard manuals, it needs the voltage value at the very end of each period, so the closer value to the very end will contribute the DCR result accuracy. The current output accuracy and voltage measurement accuracy are the basic requirements.

• Response Time. BTS 4000 responses set current in less than 10 ms (millisecond).

• Timing Control. BTS 4000 has a time accuracy of 1ms (millisecond).

• Data Acquisition Frequency. BTS 4000 has a conventional 10Hz data acquisition frequency, and 100Hz optional.

Below goes a comparison between BTS 4000 and BTS 3000. There are 2 data record frequencies adopted for the comparison – 1 second (1 Hz) and 0.1 second (10Hz). Battery was restored to its original SOC (State of Charge) after every DCR test to avoid the influence.
P.S.: 4S or 4 Series means BTS 4000, and 3S means BTS 3000

Box_Plot_of_DCR_Value

Single_Value_Chart_of_DCR