Will the MN Model MN82 RC Car Parts 7.4V 3000mAh Battery SM3P increase runtime?

Yes. Compared with the original 500mAh or 1200mAh battery, the MN Model MN82 Parts 7.4V 3000mAh Battery SM3P offers significantly longer driving time while maintaining the same 7.4V (2S) operating voltage, so no changes to the stock electronics are required.