Archos 55 Platinum features a 5-inch, 720 x 1280 pixels display, 1GB RAM, 8GB memory, 13 megapixel rear camera and 2 megapixel front camera, dual SIM connectivity, LTE, and a 2400mAh battery
Amazon.com: Synergy Digital Cell Phone Battery, Works with Archos 50c Platinum Cell Phone, (Li-ion, 3.7V, 2200mAh) Ultra High Capacity, Compatible with Archos AC50CPL, BSE70H Battery : Electronics
How to save battery life on ARCHOS 55 Platinum? - HardReset.info