Riche13,
I think you ought to approach the battery and charger manufacturers as battery technology and charger technologies have come on in leaps and bounds, chargers such as high frequency ionic chargers can charge a battery up in about 4 hrs depending on the general condition of the battery mind you if a battery has been over discharged the chargr may initiated a desulphation cycle which may take up to 11hrs to complete. I'm sure that as a student the battery companies will enthusiastically send you info on there products.

Regards Titus