Cold start

Well I have a 2005 yfz450 has a problem for the first start it will crank and crank and not fire but as soon as I hook up a car charger to battery I wait about 20 seconds and it will fire right up and run fine. They battery doesn't die and after that one start for the next 6 hours or so it will start just fine with no jump. What could this be it's got a brand new battery new regulator and new start solenoid.