Here's some info that may or may not be of help to you... i think you should be able to make 15 minutes easily enough =)

Packs: 2x 2S2P 28C SMC 9000mah Lipos wired in series for 4S
Vehicle: MBX5-T (Geared 14/46 Long Shank Pinion - apparently 4.8kg RTR says my unreliable scales at home)
Electrics: MMM/Tekno Neu 1512 2.5d/f
Race/s Vehicle Run In (Runtime): 2x 6 minute qualifiers
Temps: Batts: 110f - Motor: 130f - ESC: 110f
Cell Voltages BEFORE Charge: Pack 1 - 3.72v/3.74v - Pack 2 - 3.72v/3.74v
Cell Voltages AFTER Charge: Pack 1 - 4.20v/4.20v - Pack 2 - 4.20v/4.20v
Mah Charged Into Pack: Pack 1 - 6462Mah - Pack 2 - 6572Mah
Charge Time: 111 Minutes : 53 Seconds
Peak Pack Voltage: Pack 1 - 8.422v - Pack 2 - 8.407v
Pack Resistance: Pack 1 - 3mΩ - Pack 2 - 5mΩ