Cell-sense channel with balance resistor
9 parts
One cell, the lead that senses it, and the resistor that balances it. A 3.2 V cell with 25 mΩ internal resistance feeds a sense lead through a 1 A fuse (50 mΩ). At the lead end, a 330 Ω bleed and 100 nF filter the sense node, which a 10 MΩ meter reads. The 33 Ω balance resistor hangs off the lead end behind Sbal; Slead opens the sense lead. Close Sbal and about 97 mA flows through the cell's 25 mΩ, the fuse and the lead, so the reading sags while the cell is being balanced.
- Vcell 3.2V
- Rint 25mΩ
- F1 1A
- Slead closed
- Sbal open
- Rbal 33Ω
- Rbleed 330Ω
- C1 100nF
- Rmeter 10MΩ