I'm frequently running out of power in my iPhone by the end of the day, even though I have

Here’s the specs

Capacity: 2400mAh

Charging Time: ~3hrs

Discharging time (to iPhone): ~3hrs

Power of amplifier speaker: <1.5W

Input Voltage: 4.8 ~ 5.5V

Current input: 500-1000mA

Output Voltage: 5.0 ~ 5.5V

Current output: 100-1000mA

Quiescent power drain: <50uA

Weight: 93g

The iPower Portable Power Station is available to buy online for $44 from Brando. [From iPhone Accessories - iPower Portable Power Station with speaker]