This backup battery just bought me great service rendered during hospitalization. Fully charged, it allowed me to charge my Nokia Lumia 920 twice and this 100%. Besides the 4 small LEDs let you see the charging status of the battery. It remains for me to recharge so it makes me valuable services again. I highly recommend this battery is a 2200 mAh and 1800 mAh as shown not all users or user of a Nokia Lumia 920.