6.1 The lithium cell

I declare: solidlikelyshaky

1. Name the common chemistries (NMC, LFP, LCO, "18650" Li-ion) with their nominal voltage, their range, and which is in an EGO or Stihl pack.
2. Read a cell’s discharge curve and derive state of charge from voltage, and why that’s imprecise on the LFP plateau.
3. Explain C-rate, calculate the current a given cell can deliver, and confront it with what the tool asks.
4. Measure the capacity and internal resistance of a salvaged cell and decide whether it’s worth reusing.
5. Explain what ages a cell (depth of discharge, heat, charging in the cold, storing full) and what spares it.
6. Compare lithium to lead-acid (AGM, gel) and to NiMH: energy per kilogram, cycles, charging, cold, price; say which goes where.
7. Diagnosis: a cell with correct voltage that collapses under load, internal resistance; the measurement that proves it.