Does HyperJuice external battery have over-charge protection? Shirley June 20, 2013 22:26 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? Do I need a special cable to connect HyperJuice pure DC Car Charger with MacBook? Can I charge my HyperJuice external battery with DC charger? Battery does not charge full, hold charge, or drains faster than normal (and how to recondition). HyperJuice Dual USB-C Manual (start here) Comments 0 comments Please sign in to leave a comment.