Eton Rechargeable USB Battery Pack with Hand Turbine Power Generator, Black, NBOTU4000B

I am pleased with the feel of this device. It appears to be well built, nothing flimsy in the makeup or components. However, I expected to be able to fully charge my cell phone from the crank itself, that is not the case. The unit is meant to be fully charged, either via usb from comp or wall outlet or car, whatever, fully charge the device and then it's ready to charge other devices. It holds a decent charge, but I was hoping that even when it did not have any charge that I could utilize the hand crank and spend whatever amount of human effort it took to fully charge my phone (or get reasonably close say %70). The manufacturer recommends that you only hand crank for enough time to permit a 4 minute phone call. repeat as necessary. Overall I'm happy with it though.

Great product, recharges fast and will as advertised charge my cellphone twice on a single charge. I allowed the charger and phone to die so I could check out the crank capability and it was more than I expected. I just about 3 minutes of cranking I was able to make a phone call to my wife and talk for almost 4 minutes before it died again. The cranking can be a little tedious but for what it is designed for it's incredible. I carry it with me wherever I go and no longer have to worry about my phone going out on me or in an emergency can make a call in just a few minute if the phone dies. I highly recommend this product.

Picked this up for a friend after another buddy bought one. I like the cranking feature, but it takes a lot of cranking just to get a little charge. It's good that you can plug it in to charge it and I guess if you're out of power you could crank away for hours, but it would take a lot of cranking just to get a good charge. Excellent idea, and it would be even better if we had the technology to improve it.

Exceptionally engineered piece of equipment. Metal housing, sturdy crank, solid connections, just not something you can very easily throw in the pocket of a pair of shorts if you are heading out for the day (don't forget the cable too). Will charge your phone and someone else gadget nicely. Wish it came with a built in charging cable, and a USB plug. You have to carry unit and cable. The charging level indicator is ok, not great.

Sturdy Emergency Battery Pack that can be recharged manually. Every home should have one in case there’s no power.

Really like this product. It does exactly what it says. It charges very quickly, and have no issues charging my HTC One M8 multiple times on a single charge. The dynamo works very well but isn't the easiest to crank, but in a dire situation that shouldn't be an issue. Also it's understandably a bit big.

I charged the battery pack fully and was successful to charge my iPhone 5S. From 80% to 90% around. Then I tried it with my iPad mini. When it was connected, everything looks ok. But when I came back after 10 mins or so, I found the battery pack completely dead. Nothing worked afterward. I re-charged it many hours but nothing happened. No LED, no charging whatever I do. Amazing to see a product broken on the first day. Since, I contacted Amazon and got a refund. I liked the product, design and concept. Feel so sorry it didn't work for me.

I never leave product reviews, unless I'm ecstatic or disappointed. This is the latter. I purchased the Eton hand turbine product a month ago, and have yet to get it to charge anything. It's not like I don't know what I'm doing (I'm an Engineer). I've not torn the device apart and tested the output with a meter yet, but it certainly won't plug-and-play with my iphone 5 at all out of the box. I've contacted support ([email protected]) and had no response after 1 week. Sadly, I would not recommend purchasing products from Eton.