15 minute run times is an estimate, at best. It all depends on how hard you drive the rig, how good the battery connections are to the ESC and motor, the condition of the motor, etc.
As for charge times, it may take a hour to hour-and-a-half for the initial charge, yes, but afterwards, it won't take that long (and it beats waiting 8 or so hours). Think of it this way. My Chevy Tahoe has a 33 gallon gas tank. Even when the gauge is pegged at "E", I've never actually put 33 gallons of gas in it, more like 25 (and that's with the needle pushing past "E").
Like as been suggested, get yourself 3 or 4 packs and your brother will never be without a charged battery (unless you never charge them afterwards).