This answer explains how to save your chat on google drive and recently I got that option on WhatsApp. It says the backup will be stored on Drive as well as on my sd card, ok fine. But the question arises is, how to save my phone memory when I have backed up the chats? After installation, whatsapp is about 20MB but when I restore my messages (through backup stored on my sd card) the size jumps to 110MB+ Why that happens? Because all my whatsapp data (media) is stored on my SD card, then why it is still consuming my phone memory? I don't think plain text messages will occupy that much space.

When I started my Google drive backup even it showed Backing up 110MB but I don't want to backup the whatsapp media, I just want to backup the text messages. Even if I backup entire 110MB to Drive and delete all my media and text messages (to clear up the space consumed by whatsapp), what will happen on next backup? Will it overwrite the last backup and substitute a new backup consisting of nothing?

I got to know that there is some third party apps like Helium which can do this work. But is there something I can do without consuming more of my phone memory?