If you have to choose between these three first go with the Patriot I've tested the Best and the Romans on the machine and they're both low voltage and low performance at 2A and can't charge at full speed. The Patriots are a little better. But neither is recommended. Because this is a very common booster scheme will fail at large current voltage. If the money is not poor, you can consider the use of Dr. Deng intelligent charging treasure is a step-down program, mainly the output power of 1-3A mobile phones can be charged at full speed is a little expensive
Romas power Bank is better. The reason is that the Roma charging treasure has higher security, with multiple protection mechanisms such as overcharge protection, overvoltage protection, overcurrent protection, short circuit protection, etc., to avoid various safety problems that may occur when charging.
The best charging treasure is relatively weak in terms of safety protection, prone to battery leakage, overheating and other problems, and there are security risks. In addition, the charging speed is faster and the charging time is shorter, while compatible with a variety of electronic devices, with chargers and