2014 Malibu sometimes acts like it doesn't want to crank over to stsrt

Tried to start car..sounds like not enough power to
turn over.  Turned key off for a min and tried again
..after about 4 tries finally turned over slow but
kept running.  No check engine lights.
Went to dealer and replaced primary battery.  
About a week later saw same problem.  Cold
morning when this happened but the  next four
days this week so far has been cold and car has
started Dealer says won't be able to determine the
problem if it doesn't happen at the service.
Also, seems like when driving the car acts like it
wants to hesitate..but keeps going.  Don't know
what to do as I drive children back n forth to
school and would hate to get stuck
Don't have a second car for mine to sit at dealer
until they see the same issue,?