Need a little extra juice? You can get use this iPhone 4 Mophie case as a protective case and a portable battery back up charger. We have one and it’s really convenient but it is a little bulky. Groupon has a deal today for a re-manufactured Mophie case for just $39 + $3 shipping (ARV $79.99.) Choose from red, white, or black.

If you are new to Groupon, you can sign up here.

Love these deals? Find more daily deal posts or see a complete list of daily deal sites you should be following!