A:Answer The Pocket Juice 20,000 can be recharged at any level of its charge. However, you cannot charge it while simultaneously using it to charge another device. Depending on the level of discharge and the charger being used, it can take up 15 hours to bring it back to a full charge. I personally use a 36 watt PD charger will typically bring the Pocket Juice from 50% to full charge in less than 8 hours. Thanks & Good Luck!