Anker 321 MagGo Battery (PowerCore 5K) The Snap and Go Magnetic Power Bank Huge Capacity, Slim Design With a huge 5,000mAh capacity, Anker 321 MagGo Battery is a powerful portable charger that is still slim and lightweight-ideal for charging on the go. Long-Lasting and Reliable Boasts a battery capacity that remains at 90% even after 20 months of use, surpassing the industry standard of 60% battery capacity. Colorful and Snappy.