USB socket for recharging

The device does what it should, charges via USB my Samsung S 5230 on. How busy it is in this case, more depends on the capacity of the inserted AA batteries, as the charger.
From a technical point, I imagine it like this that the 1,2-1,5V the batteries (Does not work with batteries) transformed to 5V, thereby naturally sings the available capacity.

It is small, handy, easy to use, simply press the button for DC out a few seconds before going to my phone.
If I hang it to a USB power source such as my computer, the batteries are charged, so you have a USB AA Battery Charger has no lithium battery that is for me, I can the battery exchange by already pre-charged and have so always to take power.

It is so far only a guess, but it still takes the SolarCard this (solar cell A4 size 188g difficult) you have a battery charger on the go and does not rely on an electrical outlet for mobile devices. Under SolarCard (and thus under 400mA output power at 5V) to buy does not make sense any other devices (if they are to be mobile because) simply do not provide enough power).