I use Soshine E4S. User replaceable 18650 LiPo battery can run on 1 or 2 battery. Works great.. LCD performance tells you sufficient information on the source battery or item you are charging. It will automatically shutdown if load is less then 100mA can be annoying if your are trying to continuous run items with low power drain items.

Power rating depends on what rated battery you put in.. so no more ripoff jobs.. good thing is you can charge a coup of battery for stand by. It can be switch to deliver 2.1A or 1.0A.