It does not matter whether you use an iOS machine or an Android machine.
There is a persistent problem of loss of chat data when someone change their mobile phone.
Agree to this and your backup should be installed, replete with your conversations.
launch the app then tap the Menu icon then go to controls>Chats and calls > Backup Chats.
Attach the USB charging cord to the phone and then plug the other end into your PC.
Eject the phone, then connect your new handset and move the WhatsApp folder onto its internal storage.
With this done you should now have all your past conversations on your new Android phone.
source: www.techworm.net
