A cell that is overcharged will only appear to have a greater capacity when it is being charged...when you discharge it, the truth comes out.

It is very difficult to charge a single cell using mv thresholds...false peaking is common. 5mv is too small for a single cell...I would use 10. 5 per cell or less is great when you have 6 cells, with some losing voltage, others staying put, and others dropping. For one cell, it's far too low.

However, the best way to charge a single cell is temperature. If you have a charger with a temp sensor, set your mv threshold level to the highest it will go (or turn it off if you can) and stop charging the cell at 120F or so. With a single cell, temperature is your best guide.

Also, a single cell cannot stand high amperage discharges for any length of time. When a Turbo Matcher matches cells, it does 4 at a time. I believe this is a great flaw with the concept of cell matching, but that's a topic for another day. For example, if you take a fully charged GP3300 cell and try to discharge it at 20amps, it will drop below .9v very quickly, yiedling very few mah. The same cell in a set of 4 or more will yield full capacity under that load.

I have found that the most stable way to test cells is to charge then at 2 amps until 120F, then discharge them at 1.5 amps. I use this technique to match cells in damaged packs based on capacity. I always get the same results (+/- 30mah), no matter how many times I do this method. The same cannot be said of other methods I have tried.