...
- Charge the cells using either a DC power supply set to 4.2V, 1.0A, and monitor it until the current reaches under 100mA - OR - Use the iCharger 306B on a 1S LiPo setting at 1A.
- Use the iCharger 306B to measure internal resistance of the cells – it is one of the preconfigured tests.
- Update the result in the spreadsheet
A resistance of the probed probes used to connect to the battery must also be measured so that we can measure the actual internal resistance of the cells, and not including the resistance of the cables.
...
Setting | Value |
Discharge Condition | Discharge Current |
Discharge Current | 1, 3, or 5 Amps multiplied by the number of cells in parallel (different , for 21700 cells, multiply the 1,3, or 5 Amps by (5/3.5) in order to test equivalent C rates. |
Stop Condition | Cut-Off Voltage |
Voltage | Look on cell’s datasheet for End Voltage of Cut Off Voltage (Usually 2.5V, Samsung 35Es are 2.65V) |
...
The above is a method that I have found that works, although there might be easier methods. Keysight creates a software called BenchVue that advertises that it is able to connect to and control the Agilent 34410A multimeter. I have not tested it yet, but it is costly software.
A Note for 4P Tests
The cells get connected to the constant current load via the 12AWG cables and M3 nuts and bolts.
VERY IMPORTANT - Charge procedure for the tested cells:
- Charge 4P pack at 4.2V, with 4A constant current
- When current falls to 300mA, remove from charger
- Wait 30 minutes for voltage to settle, then start discharge test
Cell wrapping: For all 4P tests, the module is to be wrapped in blue tape in order to remove the cooling effects of circulating air. The blue tape should be attached to the black holders, and should not be touching the cells directly.
Testing a Cell
How to test a cell:
...