Don't know. I bought EasyAcc® 12000mAh Power Bank 4 USB 3.5A Output Portable Charger H... http://www.amazon.co.uk/dp/B008YRG5JQ/ref=cm_sw_r_udp_awd_GC3Ltb0TNXHQ7 and used it to charge my iPhone 4s. Hope that helps
Hi, you can tell because the device you are charging should go into charge mode. If the sun is not strong it will at least be trickle charging. To be certain, you can purchase (about £9.00), the Portapow USB power monitor, which displays either the voltage or Amps being used from the charged device from the solar panel.
I use mine to charge my Anker® Astro 3E 10000mAh Portable High Capacity Dual-Port External Battery Power Bank. What I have found is that it needs a certain amount of current (i.e. sunlight) to start charging, less than this and it will not do anything. I also own a PortaPow Solar USB Battery Pack and find that this will charge usefully with a much lower current.
Yes this will charge a Kindle (Sunshine permitting especially in the UK) if I'm right in thinking it charges from USB Socket. (like an iphone or micro usb port). Not sure what port the kindle uses to charge as I don't have on personally, but the unit does come with a USB cable and a number of adapter head. Alternatively I normally use a spare of the standard charging cable that came with my phone when charging it.