You may be wondering why it carries some heft. Well, its claim to fame is the unbelievably massive 6,300mAh battery. With moderate use, LEAGOO claims you can go up to 3.5 days. It will still return two days of battery life with heavy use. Highly impressive. Not only that, it features Pump Express Flash Charge technology that rapid charges the big battery. With the supplied 9V/3A charger, you can give the Shark 1 a full day’s worth of juice with only 30 minutes of charging.