... panel : Charging time is much longer.3. Battery difference :Duolilong use A-grand polymer Lithium-ion battery with 2400mah power, it ... circuit protection system, it can protect the iPhone.Others may use poor quality of PCB, without circuit protection system, that ... , rechargeable volume indicators will be luminous, and I=25% electricity, I,II=50% electricity ,I,II,III=100% electricity . 2.After iphone ...