How do you know when the HyperJuice Plug is fully charged? Shirley August 16, 2015 01:10 Updated Follow When the HyperJuice Plug is fully charged you will have 5 solid LED lights on. Tags: hyperjuice plug fully charged Related articles English user manual for HyperJuice AC battery How long does it take to charge the HyperJuice Plug? How to recharge the HyperJuice 1.5 / HyperJuice 2 batteries with the Modified Magsafe Adapters? How long should I charge my new HyperJuice battery? Comments 0 comments Please sign in to leave a comment.