brushless revo conversion!!

[mopar1994]

heres a short video. i cant believe how much power it has andd it wheelies even with the center diff in it. i got some q's about charging my battery. when i plugged the battery in i set the charger to 5s lipo and 4900mah is there anything else i need to set? and when i started charging it,on the bottom right hand side it said that the battery was at like 19 volts. so should i just not charge it since its only supposed to be at 18.5 volts? and how does the charger know when to stop charging?