Battery life differs for the mode:
White LED:
High 1,100 lumens; runs 5 hours
Medium 550 lumens; runs 10.5 hours
Low 125 lumens; runs 35 hours
4 Red LEDs (preserves night vision):
High: 2.7 lumens; runs 110 hours
Low: 1 lumen; runs 288 hours
Flash SOS mode: 2.7 lumens; runs 230 hours
Battery life will drop when charging other devices, the amount will depend on the time and the device. The charger is proprietary and Streamlight does not make a solar adapter for it, but if you have a solar charger with a normal wall-style AC outlet it should charge it.