CrossRoads:
I think that was a great description of how it should work Doornroos.
I would check on the discharge voltage. I'm thinking you don't want to get below 3.7V/cell.
3 Cells would be ~12.3 to 12.6V fully charged, and 11.1V when pretty discharged.
No, 3.7 vdc represents approximately the 50% remaining charge level and is often the 'nominal' voltage rating given when talking about a Li-Po cell. 3.0 is considered a good low cutoff value, and 4.2 is considered the fully charged voltage. So a 3 series cell Li-Po would could use 9 to 12.6 as it's safe workable voltage range.
Lefty