Have you double check about your installation for battery?If your battery dont want charged,I am sure you have wrong on installation.
If you increase the magnetic force of the stator of an electric motor, you will reduce the maximum speed of the motor, as well as its ideal speed. However, the power delivered at this new ideal speed will remain the same as before.
The increase of the magnetic field can be obtained by a static electromagnet put above little permanent magnets. When you want an increase in the mechanical power given by the motor at low speed, you simply switch on the electromagnet.
Note that the power of the stator can not be increased or decreased indefinitely: too power ful, it will override the magnetic field of the rotor, and block it. Too weak, it will be overridden by the magnetic field of the rotor, and be of no use.
This system can be self-regulating: at high speeds the electrix counter-force lowers the current in the stator.So best way to give output from your stator is read your manual book and you will find default setting for it.
I hope this can help solve your problem.