This phone from Huawei has a 3,750 mAh battery. Great for kids or as a backup.
Amazon
HUAWEI Nova 5T (128GB, 6GB) 6.26" LCD, Kirin 980, 48MP Quad Camera, 22.5W Fast Charge, Dual SIM GSM Unlocked Global 4G LTE International EU Plug with US Adapter (Black)
Or $80.12/mo. (x12)*