Does HyperJuice external battery have over-charge protection? Shirley June 20, 2013 22:26 Follow When the HyperJuice battery is fully charged, the voltage current will be set to trigger charge to protect the battery. Related articles How long should I charge my new HyperJuice battery? Can the HyperJuice battery with Apple Magsafe Airline adapter recharge the MacBook? English user manual for HyperJuice AC battery Comments 0 comments Please sign in to leave a comment.