ASUS Zenphone 2 Battery, BoxWave [Solar Rejuva PowerPack (5000mAh)] Solar Powered Backup Power Bank for ASUS Zenphone 2 - Jet Black 5000 mAh Internal Battery Micro USB input, standard USB output, 5v at 1 amp 4 LED Incremental Power Level Indicator Sleek, compact design stores just about anywhere Solar charging LED indicator light