There are two ways of communicating with members of your team. You can either use the canned chat control at the bottom right of the screen which will enable you to quickly send common messages to other players or you can write short sentences by tapping the chat button on the top right of the screen which will bring up the keyboard for text entry. Once you have typed your message you will be able to send it to team members or the entire battlefield. Even if your tank is destroyed in the battle you can still communicate with your team members and provide them intel like giving them the location of enemy tanks. Being helpful is in your best interest because if your team wins you will earn credits and experience.