Just watch this.....
This is what you want to do, i think..
Its called a boost converter.
This guy is lighting a 12v led on a 1.5v battery.
The coil gets charged first and then the coil discharges, plus the 1.5v of the battery in series.
So shortly you get and power boost, so to say..
It is fun to build.
I once made one with a wfc,
I always wanted to go back to it again...
Remember that circuit we build that showed more power out then in?
Thats the other variant....
Charge the coil and cell, switch off and part of the bifcoil got its charge from the cell and then power on, double power to the cell....
With a low resistance watercell, you might need to add a second transistor. 1 extra after the diode. So, one that breaks the connection to the capacitor...when you switches on the other transistor for charging the coil.