If you simply mean why is it triggered on the negative of cap to negative of battery...

If the positive is connected but the negative is not, that means that the positive potential from the cap is ALREADY sitting inside of the battery being charged. As soon as the negative side is connected, you have the negative charge popping towards the battery and the charging effect is stronger. It does make a difference.

If the neg is connected, the neg potential is sitting in the battery and when triggered on the positive, then the positive still has to make its way through the battery. The other way, the pos is already in the battery.

John or Peter can of course explain this better but I thought Free Energy Generation book did a good job at explaining it.

When the neg is discharged, the battery itself I suppose is a resistor and since it is, the anti-photon potential around the circuit is sucked towards the battery at this point of resistance.

When the positive of cap is connected to the pos of the batt, look at the battery at simply being an extension of the dipole.

Look at the coil in the simple school girl, the + of battery is ALREADY sitting inside of the coil and the coil is already an extension of the dipole of the input battery. Being an extension of the dipole on the positive side, the positive doesn't have to take the time to overcome the resistance of moving into the coil or moving into a battery.