It's important to remember when you are going through a custody battle that although you have a lot of conflict with your ex spouse in different ways of parenting over certain areas that you never bring those things up in front of the child especially during the exchanges. You need to have ways to communicate with your ex spouse not in the child's presence. Email is a great way to do that, doing that when the child is sleeping by phone might be a great way to do that but all this areas that may involve sports, schooling healthcare. You never want to involve the child in seeing the conflict and being aware of the conflict and you never want to show the child that you want them to take a side. The important thing again is when you are together in front of the child during in exchanges to both be pleasant. You could make it as fast as possible, be nice together and focus on loving and parenting the child.