gres
Full Member level 4
System allow to test a lot amount of lithium-ion cells, much easier and faster than in traditional way. Main mission is to appoint cell capacity, and print discharge characteristic. Three independent discharge channels, typical principle of work – discharge by direct current (550mA) to reach final voltage about 3V. Maximum cell capacity is 2,62Ah. Because of typical laboratory destination, and no high voltages, I didn’t make any casing. Discharger system use ATTINY26 microcontroller, discharge current is stabilized by L1084 (analog to 1086), that can be turn on by FDS9412 transistors. Glue is to secure wires.
System communicate with PC via USB slot, working thanks to VUSB library. On computer we start interface working with tcp port, that allow to communicate with discharger ( replay for one-number orders). Users interface is based on NI LabView environment.
At the picture:
- 0 channel (red) – sanyo 2,2Ah, discharge complete, capacity 1,4Ah
- 1 channel (green) – Molice 2,2Ah
- 2 channel (blue) – Panasonic 2Ah
as you can see, all three accumulators are worn out – they have very small capacity, and voltage after start discharge tool , falls very fast to 4 V and less ( all were charged to 4,16V)
software allow to save results to the file, reading files). Additional software in LabView allow to display files as a diagram.
Original text at: https://www.elektroda.pl/rtvforum/topic1581911.html