Other Parts Discussed in Thread: BQSTUDIO,
Tool/software:
I have a battery pack based on the Panasonic NCR18650BF. The pack has four cells in parallel.
After programing R2 firmware to ensure all factory defaults are loaded set the following with bqstudio:
- Programmed ChemID = 2039
- Calibrated current, voltage and temperature. After calibration I verified all readings with DMM including temperature.
- Set the following Data Memory Parameters:
Design Capacity mAh 13400 Design Capacity cWh 4824 Design Voltage 3600 Charge Term Taper Current 120 Dsg Current Threshold 2 Chg Current Threshold 25 Quit Current 1 Term Voltage 2675 Temperature Enable 1
I used the Alternate method for initial discharge
| Discharge Battery to Empty (Alternative Method): An alternative method before starting this initial discharge would be to make sure IT is disabled. The GAUGE_EN flag of the manufacturing status register would be cleared if IT is disabled. If the GAUGE_EN flag is set, clear it by sending command 0x21 or clicking the GAUGE_EN button in the command window. This is different from earlier gauges in that IT enable command can be toggled on and off. In earlier gauges, once IT is enabled, it can never be disabled via command. Disabling impedance track prevents resistance updates from occurring during this initial discharge. |
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| 1 | Set E36731A function to load. | ||||
| 2 | Set E36731A load current to 2.68A (C/5). | ||||
| 3 | Enable E36731A load (On Button illuminated) | ||||
| 4 | Wait for battery to reach Term Voltage. | ||||
| 5 | Disable E36731A load (On Button not illuminated) and disconnect power leads. | ||||
| Relax for at least 5 Hours (Alternative Method): If the alternative method of disabling IT was used, IT enable command should be sent after the 5 hour wait time. This forces an OCV measurement to be taken, and because the cells are sufficiently rested, this OCV value is qualified for a Qmax update. |
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| 1 | Wait for 5 hrs. until discharged battery stabilizes. | ||||
| 2 | Click "Start Log" in registers tab. Interval set in File Menu-->Window-->Preferences-->Registers-->Scan/Log Interval (ms)--> 4000 | ||||
| 3 | Click "Auto Export" in Data Memory tab. Interval set in File Menu-->Window-->Preferences-->Data Memory-->Auto Export Interval (ms)--> 600000 | ||||
| 4 | Issue command GAUGE_EN, until GAUGE_EN = '1' and QEN ='1' (Don't change GAUGE_EN state for the remainder of the learning cycle) | ||||
| 5 | Issue command RESET | ||||
| 6 | Update Status should now be 0x04 (IT Enabled) and VOK = '0' and RDIS = '1' | ||||
| 7 | Wait for IT Status Register RDIS = '0' Highlighted Green | ||||
| 8 | Wait for IT Status Register VOK = '0' Highlighted Green | ||||
| 9 | Wait for IT Status Register REST = '1' Highlighted Green | ||||
| Charge Battery to Full • A typical C/2 charge rate is recommended; however, the charge rate is of no consequence. • Make sure IT is already enabled at this point before the start of charge (the [Gauge_EN] bit in the manufacturing status() register should be set). |
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| 1 | Set E36731A function to Power Supply. | ||||
| 2 | Set E36731A current limit to 2.68A (C/5). | ||||
| 3 | Set E36731A voltage to 4.2V. | ||||
| 4 | Enable E36731A output (On Button illuminated) | ||||
| 5 | At the start of charge, VOK bit in the IT status register sets automatically. | ||||
| 6 | At the end of charge the FC bit in the Battery Status register should be set automatically. If it did not set then a full charge was not properly detected and the learning cycle fails. Correct either the charging conditions or the relevant dataflash settings to ensure the [FC] bit gets set and try again from the beginning. |
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The FC bit never set. I gave up after the taper reached around 70mA.
I have attached the register log and data memory auto export data.
Did I forget to set a parameter, or did I mess up one of the parameters called out in the app note: SLUA903?
